Box API

Package gofpdf implements a PDF document generator with high level support for text, drawing and images. - UTF-8 support - Choice of measurement unit, page format and margins - Page header and footer management - Automatic page breaks, line breaks, and text justification - Inclusion of JPEG, PNG, GIF, TIFF and basic path-only SVG images - Colors, gradients and alpha channel transparency - Outline bookmarks - Internal and external links - TrueType, Type1 and encoding support - Page compression - Lines, Bézier curves, arcs, and ellipses - Rotation, scaling, skewing, translation, and mirroring - Clipping - Document protection - Layers - Templates - Barcodes - Charting facility - Import PDFs as templates gofpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. gofpdf supports UTF-8 TrueType fonts and “right-to-left” languages. Note that Chinese, Japanese, and Korean characters may not be included in many general purpose fonts. For these languages, a specialized font (for example, NotoSansSC for simplified Chinese) can be used. Also, support is provided to automatically translate UTF-8 runes to code page encodings for languages that have fewer than 256 glyphs. This repository will not be maintained, at least for some unknown duration. But it is hoped that gofpdf has a bright future in the open source world. Due to Go’s promise of compatibility, gofpdf should continue to function without modification for a longer time than would be the case with many other languages. Forks should be based on the last viable commit. Tools such as active-forks can be used to select a fork that looks promising for your needs. If a particular fork looks like it has taken the lead in attracting followers, this README will be updated to point people in that direction. The efforts of all contributors to this project have been deeply appreciated. Best wishes to all of you. To install the package on your system, run Later, to receive updates, run The following Go code generates a simple PDF file. See the functions in the fpdf_test.go file (shown as examples in this documentation) for more advanced PDF examples. If an error occurs in an Fpdf method, an internal error field is set. After this occurs, Fpdf method calls typically return without performing any operations and the error state is retained. This error management scheme facilitates PDF generation since individual method calls do not need to be examined for failure; it is generally sufficient to wait until after Output() is called. For the same reason, if an error occurs in the calling application during PDF generation, it may be desirable for the application to transfer the error to the Fpdf instance by calling the SetError() method or the SetErrorf() method. At any time during the life cycle of the Fpdf instance, the error state can be determined with a call to Ok() or Err(). The error itself can be retrieved with a call to Error(). This package is a relatively straightforward translation from the original FPDF library written in PHP (despite the caveat in the introduction to Effective Go). The API names have been retained even though the Go idiom would suggest otherwise (for example, pdf.GetX() is used rather than simply pdf.X()). The similarity of the two libraries makes the original FPDF website a good source of information. It includes a forum and FAQ. However, some internal changes have been made. Page content is built up using buffers (of type bytes.Buffer) rather than repeated string concatenation. Errors are handled as explained above rather than panicking. Output is generated through an interface of type io.Writer or io.WriteCloser. A number of the original PHP methods behave differently based on the type of the arguments that are passed to them; in these cases additional methods have been exported to provide similar functionality. Font definition files are produced in JSON rather than PHP. A side effect of running go test ./... is the production of a number of example PDFs. These can be found in the gofpdf/pdf directory after the tests complete. Please note that these examples run in the context of a test. In order run an example as a standalone application, you’ll need to examine fpdf_test.go for some helper routines, for example exampleFilename() and summary(). Example PDFs can be compared with reference copies in order to verify that they have been generated as expected. This comparison will be performed if a PDF with the same name as the example PDF is placed in the gofpdf/pdf/reference directory and if the third argument to ComparePDFFiles() in internal/example/example.go is true. (By default it is false.) The routine that summarizes an example will look for this file and, if found, will call ComparePDFFiles() to check the example PDF for equality with its reference PDF. If differences exist between the two files they will be printed to standard output and the test will fail. If the reference file is missing, the comparison is considered to succeed. In order to successfully compare two PDFs, the placement of internal resources must be consistent and the internal creation timestamps must be the same. To do this, the methods SetCatalogSort() and SetCreationDate() need to be called for both files. This is done automatically for all examples. Nothing special is required to use the standard PDF fonts (courier, helvetica, times, zapfdingbats) in your documents other than calling SetFont(). You should use AddUTF8Font() or AddUTF8FontFromBytes() to add a TrueType UTF-8 encoded font. Use RTL() and LTR() methods switch between “right-to-left” and “left-to-right” mode. In order to use a different non-UTF-8 TrueType or Type1 font, you will need to generate a font definition file and, if the font will be embedded into PDFs, a compressed version of the font file. This is done by calling the MakeFont function or using the included makefont command line utility. To create the utility, cd into the makefont subdirectory and run “go build”. This will produce a standalone executable named makefont. Select the appropriate encoding file from the font subdirectory and run the command as in the following example. In your PDF generation code, call AddFont() to load the font and, as with the standard fonts, SetFont() to begin using it. Most examples, including the package example, demonstrate this method. Good sources of free, open-source fonts include Google Fonts and DejaVu Fonts. The draw2d package is a two dimensional vector graphics library that can generate output in different forms. It uses gofpdf for its document production mode. gofpdf is a global community effort and you are invited to make it even better. If you have implemented a new feature or corrected a problem, please consider contributing your change to the project. A contribution that does not directly pertain to the core functionality of gofpdf should be placed in its own directory directly beneath the contrib directory. Here are guidelines for making submissions. Your change should - be compatible with the MIT License - be properly documented - be formatted with go fmt - include an example in fpdf_test.go if appropriate - conform to the standards of golint and go vet, that is, golint . and go vet . should not generate any warnings - not diminish test coverage Pull requests are the preferred means of accepting your changes. gofpdf is released under the MIT License. It is copyrighted by Kurt Jung and the contributors acknowledged below. This package’s code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Bruno Michel has provided valuable assistance with the code. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF transparency script by Martin Hall-May. Support for gradients and clipping is adapted from FPDF scripts by Andreas Würmser. Support for outline bookmarks is adapted from Olivier Plathey by Manuel Cornes. Layer support is adapted from Olivier Plathey. Support for transformations is adapted from the FPDF transformation script by Moritz Wagner and Andreas Würmser. PDF protection is adapted from the work of Klemen Vodopivec for the FPDF product. Lawrence Kesteloot provided code to allow an image’s extent to be determined prior to placement. Support for vertical alignment within a cell was provided by Stefan Schroeder. Ivan Daniluk generalized the font and image loading code to use the Reader interface while maintaining backward compatibility. Anthony Starks provided code for the Polygon function. Robert Lillack provided the Beziergon function and corrected some naming issues with the internal curve function. Claudio Felber provided implementations for dashed line drawing and generalized font loading. Stani Michiels provided support for multi-segment path drawing with smooth line joins, line join styles, enhanced fill modes, and has helped greatly with package presentation and tests. Templating is adapted by Marcus Downing from the FPDF_Tpl library created by Jan Slabon and Setasign. Jelmer Snoeck contributed packages that generate a variety of barcodes and help with registering images on the web. Jelmer Snoek and Guillermo Pascual augmented the basic HTML functionality with aligned text. Kent Quirk implemented backwards-compatible support for reading DPI from images that support it, and for setting DPI manually and then having it properly taken into account when calculating image size. Paulo Coutinho provided support for static embedded fonts. Dan Meyers added support for embedded JavaScript. David Fish added a generic alias-replacement function to enable, among other things, table of contents functionality. Andy Bakun identified and corrected a problem in which the internal catalogs were not sorted stably. Paul Montag added encoding and decoding functionality for templates, including images that are embedded in templates; this allows templates to be stored independently of gofpdf. Paul also added support for page boxes used in printing PDF documents. Wojciech Matusiak added supported for word spacing. Artem Korotkiy added support of UTF-8 fonts. Dave Barnes added support for imported objects and templates. Brigham Thompson added support for rounded rectangles. Joe Westcott added underline functionality and optimized image storage. Benoit KUGLER contributed support for rectangles with corners of unequal radius, modification times, and for file attachments and annotations. - Remove all legacy code page font support; use UTF-8 exclusively - Improve test coverage as reported by the coverage tool. Example demonstrates the generation of a simple PDF document. Note that since only core fonts are used (in this case Arial, a synonym for Helvetica), an empty string can be specified for the font directory in the call to New(). Note also that the example.Filename() and example.Summary() functions belong to a separate, internal package and are not part of the gofpdf library. If an error occurs at some point during the construction of the document, subsequent method calls exit immediately and the error is finally retrieved with the output call where it can be handled by the application.

Package tcell provides a lower-level, portable API for building programs that interact with terminals or consoles. It works with both common (and many uncommon!) terminals or terminal emulators, and Windows console implementations. It provides support for up to 256 colors, text attributes, and box drawing elements. A database of terminals built from a real terminfo database is provided, along with code to generate new database entries. Tcell offers very rich support for mice, dependent upon the terminal of course. (Windows, XTerm, and iTerm 2 are known to work very well.) If the environment is not Unicode by default, such as an ISO8859 based locale or GB18030, Tcell can convert input and output, so that your terminal can operate in whatever locale is most convenient, while the application program can just assume "everything is UTF-8". Reasonable defaults are used for updating characters to something suitable for display. Unicode box drawing characters will be converted to use the alternate character set of your terminal, if native conversions are not available. If no ACS is available, then some ASCII fallbacks will be used. Note that support for non-UTF-8 locales (other than C) must be enabled by the application using RegisterEncoding() -- we don't have them all enabled by default to avoid bloating the application unnecessarily. (These days UTF-8 is good enough for almost everyone, and nobody should be using legacy locales anymore.) Also, actual glyphs for various code point will only be displayed if your terminal or emulator (or the font the emulator is using) supports them. A rich set of key codes is supported, with support for up to 65 function keys, and various other special keys.

SQL Schema migration tool for Go. Key features: To install the library and command line program, use the following: The main command is called sql-migrate. Each command requires a configuration file (which defaults to dbconfig.yml, but can be specified with the -config flag). This config file should specify one or more environments: The `table` setting is optional and will default to `gorp_migrations`. The environment that will be used can be specified with the -env flag (defaults to development). Use the --help flag in combination with any of the commands to get an overview of its usage: The up command applies all available migrations. By contrast, down will only apply one migration by default. This behavior can be changed for both by using the -limit parameter. The redo command will unapply the last migration and reapply it. This is useful during development, when you're writing migrations. Use the status command to see the state of the applied migrations: If you are using MySQL, you must append ?parseTime=true to the datasource configuration. For example: See https://github.com/go-sql-driver/mysql#parsetime for more information. Import sql-migrate into your application: Set up a source of migrations, this can be from memory, from a set of files or from bindata (more on that later): Then use the Exec function to upgrade your database: Note that n can be greater than 0 even if there is an error: any migration that succeeded will remain applied even if a later one fails. The full set of capabilities can be found in the API docs below. Migrations are defined in SQL files, which contain a set of SQL statements. Special comments are used to distinguish up and down migrations. You can put multiple statements in each block, as long as you end them with a semicolon (;). If you have complex statements which contain semicolons, use StatementBegin and StatementEnd to indicate boundaries: The order in which migrations are applied is defined through the filename: sql-migrate will sort migrations based on their name. It's recommended to use an increasing version number or a timestamp as the first part of the filename. Normally each migration is run within a transaction in order to guarantee that it is fully atomic. However some SQL commands (for example creating an index concurrently in PostgreSQL) cannot be executed inside a transaction. In order to execute such a command in a migration, the migration can be run using the notransaction option: If you like your Go applications self-contained (that is: a single binary): use packr (https://github.com/gobuffalo/packr) to embed the migration files. Just write your migration files as usual, as a set of SQL files in a folder. Use the PackrMigrationSource in your application to find the migrations: If you already have a box and would like to use a subdirectory: As an alternative, but slightly less maintained, you can use bindata (https://github.com/shuLhan/go-bindata) to embed the migration files. Just write your migration files as usual, as a set of SQL files in a folder. Then use bindata to generate a .go file with the migrations embedded: The resulting bindata.go file will contain your migrations. Remember to regenerate your bindata.go file whenever you add/modify a migration (go generate will help here, once it arrives). Use the AssetMigrationSource in your application to find the migrations: Both Asset and AssetDir are functions provided by bindata. Then proceed as usual. Adding a new migration source means implementing MigrationSource. The resulting slice of migrations will be executed in the given order, so it should usually be sorted by the Id field.

Package tcell provides a lower-level, portable API for building programs that interact with terminals or consoles. It works with both common (and many uncommon!) terminals or terminal emulators, and Windows console implementations. It provides support for up to 256 colors, text attributes, and box drawing elements. A database of terminals built from a real terminfo database is provided, along with code to generate new database entries. Tcell offers very rich support for mice, dependent upon the terminal of course. (Windows, XTerm, and iTerm 2 are known to work very well.) If the environment is not Unicode by default, such as an ISO8859 based locale or GB18030, Tcell can convert input and output, so that your terminal can operate in whatever locale is most convenient, while the application program can just assume "everything is UTF-8". Reasonable defaults are used for updating characters to something suitable for display. Unicode box drawing characters will be converted to use the alternate character set of your terminal, if native conversions are not available. If no ACS is available, then some ASCII fallbacks will be used. Note that support for non-UTF-8 locales (other than C) must be enabled by the application using RegisterEncoding() -- we don't have them all enabled by default to avoid bloating the application unneccessarily. (These days UTF-8 is good enough for almost everyone, and nobody should be using legacy locales anymore.) Also, actual glyphs for various code point will only be displayed if your terminal or emulator (or the font the emulator is using) supports them. A rich set of keycodes is supported, with support for up to 65 function keys, and various other special keys.

Package goji provides an out-of-box web server with reasonable defaults. Example: This package exists purely as a convenience to programmers who want to get started as quickly as possible. It draws almost all of its code from goji's subpackages, the most interesting of which is goji/web, and where most of the documentation for the web framework lives. A side effect of this package's ease-of-use is the fact that it is opinionated. If you don't like (or have outgrown) its opinions, it should be straightforward to use the APIs of goji's subpackages to reimplement things to your liking. Both methods of using this library are equally well supported. Goji requires Go 1.2 or newer.

Package gosnowflake is a pure Go Snowflake driver for the database/sql package. Clients can use the database/sql package directly. For example: Use the Open() function to create a database handle with connection parameters: The Go Snowflake Driver supports the following connection syntaxes (or data source name (DSN) formats): where all parameters must be escaped or use Config and DSN to construct a DSN string. For information about account identifiers, see the Snowflake documentation (https://docs.snowflake.com/en/user-guide/admin-account-identifier.html). The following example opens a database handle with the Snowflake account named "my_account" under the organization named "my_organization", where the username is "jsmith", password is "mypassword", database is "mydb", schema is "testschema", and warehouse is "mywh": The connection string (DSN) can contain both connection parameters (described below) and session parameters (https://docs.snowflake.com/en/sql-reference/parameters.html). The following connection parameters are supported: account <string>: Specifies your Snowflake account, where "<string>" is the account identifier assigned to your account by Snowflake. For information about account identifiers, see the Snowflake documentation (https://docs.snowflake.com/en/user-guide/admin-account-identifier.html). If you are using a global URL, then append the connection group and ".global" (e.g. "<account_identifier>-<connection_group>.global"). The account identifier and the connection group are separated by a dash ("-"), as shown above. This parameter is optional if your account identifier is specified after the "@" character in the connection string. region <string>: DEPRECATED. You may specify a region, such as "eu-central-1", with this parameter. However, since this parameter is deprecated, it is best to specify the region as part of the account parameter. For details, see the description of the account parameter. database: Specifies the database to use by default in the client session (can be changed after login). schema: Specifies the database schema to use by default in the client session (can be changed after login). warehouse: Specifies the virtual warehouse to use by default for queries, loading, etc. in the client session (can be changed after login). role: Specifies the role to use by default for accessing Snowflake objects in the client session (can be changed after login). passcode: Specifies the passcode provided by Duo when using multi-factor authentication (MFA) for login. passcodeInPassword: false by default. Set to true if the MFA passcode is embedded in the login password. Appends the MFA passcode to the end of the password. loginTimeout: Specifies the timeout, in seconds, for login. The default is 60 seconds. The login request gives up after the timeout length if the HTTP response is success. requestTimeout: Specifies the timeout, in seconds, for a query to complete. 0 (zero) specifies that the driver should wait indefinitely. The default is 0 seconds. The query request gives up after the timeout length if the HTTP response is success. authenticator: Specifies the authenticator to use for authenticating user credentials: To use the internal Snowflake authenticator, specify snowflake (Default). If you want to cache your MFA logins, use AuthTypeUsernamePasswordMFA authenticator. To authenticate through Okta, specify https://<okta_account_name>.okta.com (URL prefix for Okta). To authenticate using your IDP via a browser, specify externalbrowser. To authenticate via OAuth, specify oauth and provide an OAuth Access Token (see the token parameter below). application: Identifies your application to Snowflake Support. disableOCSPChecks: false by default. Set to true to bypass the Online Certificate Status Protocol (OCSP) certificate revocation check. IMPORTANT: Change the default value for testing or emergency situations only. insecureMode: deprecated. Use disableOCSPChecks instead. token: a token that can be used to authenticate. Should be used in conjunction with the "oauth" authenticator. client_session_keep_alive: Set to true have a heartbeat in the background every hour to keep the connection alive such that the connection session will never expire. Care should be taken in using this option as it opens up the access forever as long as the process is alive. ocspFailOpen: true by default. Set to false to make OCSP check fail closed mode. validateDefaultParameters: true by default. Set to false to disable checks on existence and privileges check for Database, Schema, Warehouse and Role when setting up the connection tracing: Specifies the logging level to be used. Set to error by default. Valid values are trace, debug, info, print, warning, error, fatal, panic. disableQueryContextCache: disables parsing of query context returned from server and resending it to server as well. Default value is false. clientConfigFile: specifies the location of the client configuration json file. In this file you can configure Easy Logging feature. disableSamlURLCheck: disables the SAML URL check. Default value is false. All other parameters are interpreted as session parameters (https://docs.snowflake.com/en/sql-reference/parameters.html). For example, the TIMESTAMP_OUTPUT_FORMAT session parameter can be set by adding: A complete connection string looks similar to the following: Session-level parameters can also be set by using the SQL command "ALTER SESSION" (https://docs.snowflake.com/en/sql-reference/sql/alter-session.html). Alternatively, use OpenWithConfig() function to create a database handle with the specified Config. # Connection Config You can also connect to your warehouse using the connection config. The dbSql library states that when you want to take advantage of driver-specific connection features that aren’t available in a connection string. Each driver supports its own set of connection properties, often providing ways to customize the connection request specific to the DBMS For example: If you are using this method, you dont need to pass a driver name to specify the driver type in which you are looking to connect. Since the driver name is not needed, you can optionally bypass driver registration on startup. To do this, set `GOSNOWFLAKE_SKIP_REGISTERATION` in your environment. This is useful you wish to register multiple verions of the driver. Note: GOSNOWFLAKE_SKIP_REGISTERATION should not be used if sql.Open() is used as the method to connect to the server, as sql.Open will require registration so it can map the driver name to the driver type, which in this case is "snowflake" and SnowflakeDriver{}. You can load the connnection configuration with .toml file format. With two environment variables SNOWFLAKE_HOME(connections.toml file directory) SNOWFLAKE_DEFAULT_CONNECTION_NAME(DSN name), the driver will search the config file and load the connection. You can find how to use this connection way at ./cmd/tomlfileconnection or Snowflake doc: https://docs.snowflake.com/en/developer-guide/snowflake-cli-v2/connecting/specify-credentials The Go Snowflake Driver honors the environment variables HTTP_PROXY, HTTPS_PROXY and NO_PROXY for the forward proxy setting. NO_PROXY specifies which hostname endings should be allowed to bypass the proxy server, e.g. no_proxy=.amazonaws.com means that Amazon S3 access does not need to go through the proxy. NO_PROXY does not support wildcards. Each value specified should be one of the following: The end of a hostname (or a complete hostname), for example: ".amazonaws.com" or "xy12345.snowflakecomputing.com". An IP address, for example "192.196.1.15". If more than one value is specified, values should be separated by commas, for example: By default, the driver's builtin logger is exposing logrus's FieldLogger and default at INFO level. Users can use SetLogger in driver.go to set a customized logger for gosnowflake package. In order to enable debug logging for the driver, user could use SetLogLevel("debug") in SFLogger interface as shown in demo code at cmd/logger.go. To redirect the logs SFlogger.SetOutput method could do the work. If you want to define S3 client logging, override S3LoggingMode variable using configuration: https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/aws#ClientLogMode Example: A custom query tag can be set in the context. Each query run with this context will include the custom query tag as metadata that will appear in the Query Tag column in the Query History log. For example: A specific query request ID can be set in the context and will be passed through in place of the default randomized request ID. For example: If you need query ID for your query you have to use raw connection. For queries: ``` ``` For execs: ``` ``` The result of your query can be retrieved by setting the query ID in the WithFetchResultByID context. ``` ``` From 0.5.0, a signal handling responsibility has moved to the applications. If you want to cancel a query/command by Ctrl+C, add a os.Interrupt trap in context to execute methods that can take the context parameter (e.g. QueryContext, ExecContext). See cmd/selectmany.go for the full example. The Go Snowflake Driver now supports the Arrow data format for data transfers between Snowflake and the Golang client. The Arrow data format avoids extra conversions between binary and textual representations of the data. The Arrow data format can improve performance and reduce memory consumption in clients. Snowflake continues to support the JSON data format. The data format is controlled by the session-level parameter GO_QUERY_RESULT_FORMAT. To use JSON format, execute: The valid values for the parameter are: If the user attempts to set the parameter to an invalid value, an error is returned. The parameter name and the parameter value are case-insensitive. This parameter can be set only at the session level. Usage notes: The Arrow data format reduces rounding errors in floating point numbers. You might see slightly different values for floating point numbers when using Arrow format than when using JSON format. In order to take advantage of the increased precision, you must pass in the context.Context object provided by the WithHigherPrecision function when querying. Traditionally, the rows.Scan() method returned a string when a variable of types interface was passed in. Turning on the flag ENABLE_HIGHER_PRECISION via WithHigherPrecision will return the natural, expected data type as well. For some numeric data types, the driver can retrieve larger values when using the Arrow format than when using the JSON format. For example, using Arrow format allows the full range of SQL NUMERIC(38,0) values to be retrieved, while using JSON format allows only values in the range supported by the Golang int64 data type. Users should ensure that Golang variables are declared using the appropriate data type for the full range of values contained in the column. For an example, see below. When using the Arrow format, the driver supports more Golang data types and more ways to convert SQL values to those Golang data types. The table below lists the supported Snowflake SQL data types and the corresponding Golang data types. The columns are: The SQL data type. The default Golang data type that is returned when you use snowflakeRows.Scan() to read data from Arrow data format via an interface{}. The possible Golang data types that can be returned when you use snowflakeRows.Scan() to read data from Arrow data format directly. The default Golang data type that is returned when you use snowflakeRows.Scan() to read data from JSON data format via an interface{}. (All returned values are strings.) The standard Golang data type that is returned when you use snowflakeRows.Scan() to read data from JSON data format directly. Go Data Types for Scan() =================================================================================================================== | ARROW | JSON =================================================================================================================== SQL Data Type | Default Go Data Type | Supported Go Data | Default Go Data Type | Supported Go Data | for Scan() interface{} | Types for Scan() | for Scan() interface{} | Types for Scan() =================================================================================================================== BOOLEAN | bool | string | bool ------------------------------------------------------------------------------------------------------------------- VARCHAR | string | string ------------------------------------------------------------------------------------------------------------------- DOUBLE | float32, float64 [1] , [2] | string | float32, float64 ------------------------------------------------------------------------------------------------------------------- INTEGER that | int, int8, int16, int32, int64 | string | int, int8, int16, fits in int64 | [1] , [2] | | int32, int64 ------------------------------------------------------------------------------------------------------------------- INTEGER that doesn't | int, int8, int16, int32, int64, *big.Int | string | error fit in int64 | [1] , [2] , [3] , [4] | ------------------------------------------------------------------------------------------------------------------- NUMBER(P, S) | float32, float64, *big.Float | string | float32, float64 where S > 0 | [1] , [2] , [3] , [5] | ------------------------------------------------------------------------------------------------------------------- DATE | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIME | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIMESTAMP_LTZ | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIMESTAMP_NTZ | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- TIMESTAMP_TZ | time.Time | string | time.Time ------------------------------------------------------------------------------------------------------------------- BINARY | []byte | string | []byte ------------------------------------------------------------------------------------------------------------------- ARRAY [6] | string / array | string / array ------------------------------------------------------------------------------------------------------------------- OBJECT [6] | string / struct | string / struct ------------------------------------------------------------------------------------------------------------------- VARIANT | string | string ------------------------------------------------------------------------------------------------------------------- MAP | map | map [1] Converting from a higher precision data type to a lower precision data type via the snowflakeRows.Scan() method can lose low bits (lose precision), lose high bits (completely change the value), or result in error. [2] Attempting to convert from a higher precision data type to a lower precision data type via interface{} causes an error. [3] Higher precision data types like *big.Int and *big.Float can be accessed by querying with a context returned by WithHigherPrecision(). [4] You cannot directly Scan() into the alternative data types via snowflakeRows.Scan(), but can convert to those data types by using .Int64()/.String()/.Uint64() methods. For an example, see below. [5] You cannot directly Scan() into the alternative data types via snowflakeRows.Scan(), but can convert to those data types by using .Float32()/.String()/.Float64() methods. For an example, see below. [6] Arrays and objects can be either semistructured or structured, see more info in section below. Note: SQL NULL values are converted to Golang nil values, and vice-versa. Snowflake supports two flavours of "structured data" - semistructured and structured. Semistructured types are variants, objects and arrays without schema. When data is fetched, it's represented as strings and the client is responsible for its interpretation. Example table definition: The data not have any corresponding schema, so values in table may be slightly different. Semistuctured variants, objects and arrays are always represented as strings for scanning: When inserting, a marker indicating correct type must be used, for example: Structured types differentiate from semistructured types by having specific schema. In all rows of the table, values must conform to this schema. Example table definition: To retrieve structured objects, follow these steps: 1. Create a struct implementing sql.Scanner interface, example: a) b) Automatic scan goes through all fields in a struct and read object fields. Struct fields have to be public. Embedded structs have to be pointers. Matching name is built using struct field name with first letter lowercase. Additionally, `sf` tag can be added: - first value is always a name of a field in an SQL object - additionally `ignore` parameter can be passed to omit this field 2. Use WithStructuredTypesEnabled context while querying data. 3. Use it in regular scan: See StructuredObject for all available operations including null support, embedding nested structs, etc. Retrieving array of simple types works exactly the same like normal values - using Scan function. You can use WithMapValuesNullable and WithArrayValuesNullable contexts to handle null values in, respectively, maps and arrays of simple types in the database. In that case, sql null types will be used: If you want to scan array of structs, you have to use a helper function ScanArrayOfScanners: Retrieving structured maps is very similar to retrieving arrays: To bind structured objects use: 1. Create a type which implements a StructuredObjectWriter interface, example: a) b) 2. Use an instance as regular bind. 3. If you need to bind nil value, use special syntax: Binding structured arrays are like any other parameter. The only difference is - if you want to insert empty array (not nil but empty), you have to use: The following example shows how to retrieve very large values using the math/big package. This example retrieves a large INTEGER value to an interface and then extracts a big.Int value from that interface. If the value fits into an int64, then the code also copies the value to a variable of type int64. Note that a context that enables higher precision must be passed in with the query. If the variable named "rows" is known to contain a big.Int, then you can use the following instead of scanning into an interface and then converting to a big.Int: If the variable named "rows" contains a big.Int, then each of the following fails: Similar code and rules also apply to big.Float values. If you are not sure what data type will be returned, you can use code similar to the following to check the data type of the returned value: You can retrieve data in a columnar format similar to the format a server returns, without transposing them to rows. When working with the arrow columnar format in go driver, ArrowBatch structs are used. These are structs mostly corresponding to data chunks received from the backend. They allow for access to specific arrow.Record structs. An ArrowBatch can exist in a state where the underlying data has not yet been loaded. The data is downloaded and translated only on demand. Translation options are retrieved from a context.Context interface, which is either passed from query context or set by the user using WithContext(ctx) method. In order to access them you must use `WithArrowBatches` context, similar to the following: This returns []*ArrowBatch. ArrowBatch functions: GetRowCount(): Returns the number of rows in the ArrowBatch. Note that this returns 0 if the data has not yet been loaded, irrespective of it’s actual size. WithContext(ctx context.Context): Sets the context of the ArrowBatch to the one provided. Note that the context will not retroactively apply to data that has already been downloaded. For example: will produce the same result in records1 and records2, irrespective of the newly provided ctx. Context worth noting are: -WithArrowBatchesTimestampOption -WithHigherPrecision -WithArrowBatchesUtf8Validation described in more detail later. Fetch(): Returns the underlying records as *[]arrow.Record. When this function is called, the ArrowBatch checks whether the underlying data has already been loaded, and downloads it if not. Limitations: How to handle timestamps in Arrow batches: Snowflake returns timestamps natively (from backend to driver) in multiple formats. The Arrow timestamp is an 8-byte data type, which is insufficient to handle the larger date and time ranges used by Snowflake. Also, Snowflake supports 0-9 (nanosecond) digit precision for seconds, while Arrow supports only 3 (millisecond), 6 (microsecond), an 9 (nanosecond) precision. Consequently, Snowflake uses a custom timestamp format in Arrow, which differs on timestamp type and precision. If you want to use timestamps in Arrow batches, you have two options: How to handle invalid UTF-8 characters in Arrow batches: Snowflake previously allowed users to upload data with invalid UTF-8 characters. Consequently, Arrow records containing string columns in Snowflake could include these invalid UTF-8 characters. However, according to the Arrow specifications (https://arrow.apache.org/docs/cpp/api/datatype.html and https://github.com/apache/arrow/blob/a03d957b5b8d0425f9d5b6c98b6ee1efa56a1248/go/arrow/datatype.go#L73-L74), Arrow string columns should only contain UTF-8 characters. To address this issue and prevent potential downstream disruptions, the context WithArrowBatchesUtf8Validation, is introduced. When enabled, this feature iterates through all values in string columns, identifying and replacing any invalid characters with `�`. This ensures that Arrow records conform to the UTF-8 standards, preventing validation failures in downstream services like the Rust Arrow library that impose strict validation checks. How to handle higher precision in Arrow batches: To preserve BigDecimal values within Arrow batches, use WithHigherPrecision. This offers two main benefits: it helps avoid precision loss and defers the conversion to upstream services. Alternatively, without this setting, all non-zero scale numbers will be converted to float64, potentially resulting in loss of precision. Zero-scale numbers (DECIMAL256, DECIMAL128) will be converted to int64, which could lead to overflow. WHen using NUMBERs with non zero scale, the value is returned as an integer type and a scale is provided in record metadata. Example. When we have a 123.45 value that comes from NUMBER(9, 4), it will be represented as 1234500 with scale equal to 4. It is a client responsibility to interpret it correctly. Also - see limitations section above. Binding allows a SQL statement to use a value that is stored in a Golang variable. Without binding, a SQL statement specifies values by specifying literals inside the statement. For example, the following statement uses the literal value “42“ in an UPDATE statement: With binding, you can execute a SQL statement that uses a value that is inside a variable. For example: The “?“ inside the “VALUES“ clause specifies that the SQL statement uses the value from a variable. Binding data that involves time zones can require special handling. For details, see the section titled "Timestamps with Time Zones". Version 1.6.23 (and later) of the driver takes advantage of sql.Null types which enables the proper handling of null parameters inside function calls, i.e.: The timestamp nullability had to be achieved by wrapping the sql.NullTime type as the Snowflake provides several date and time types which are mapped to single Go time.Time type: Version 1.3.9 (and later) of the Go Snowflake Driver supports the ability to bind an array variable to a parameter in a SQL INSERT statement. You can use this technique to insert multiple rows in a single batch. As an example, the following code inserts rows into a table that contains integer, float, boolean, and string columns. The example binds arrays to the parameters in the INSERT statement. If the array contains SQL NULL values, use slice []interface{}, which allows Golang nil values. This feature is available in version 1.6.12 (and later) of the driver. For example, For slices []interface{} containing time.Time values, a binding parameter flag is required for the preceding array variable in the Array() function. This feature is available in version 1.6.13 (and later) of the driver. For example, Note: For alternative ways to load data into the Snowflake database (including bulk loading using the COPY command), see Loading Data into Snowflake (https://docs.snowflake.com/en/user-guide-data-load.html). When you use array binding to insert a large number of values, the driver can improve performance by streaming the data (without creating files on the local machine) to a temporary stage for ingestion. The driver automatically does this when the number of values exceeds a threshold (no changes are needed to user code). In order for the driver to send the data to a temporary stage, the user must have the following privilege on the schema: If the user does not have this privilege, the driver falls back to sending the data with the query to the Snowflake database. In addition, the current database and schema for the session must be set. If these are not set, the CREATE TEMPORARY STAGE command executed by the driver can fail with the following error: For alternative ways to load data into the Snowflake database (including bulk loading using the COPY command), see Loading Data into Snowflake (https://docs.snowflake.com/en/user-guide-data-load.html). Go's database/sql package supports the ability to bind a parameter in a SQL statement to a time.Time variable. However, when the client binds data to send to the server, the driver cannot determine the correct Snowflake date/timestamp data type to associate with the binding parameter. For example: To resolve this issue, a binding parameter flag is introduced that associates any subsequent time.Time type to the DATE, TIME, TIMESTAMP_LTZ, TIMESTAMP_NTZ or BINARY data type. The above example could be rewritten as follows: The driver fetches TIMESTAMP_TZ (timestamp with time zone) data using the offset-based Location types, which represent a collection of time offsets in use in a geographical area, such as CET (Central European Time) or UTC (Coordinated Universal Time). The offset-based Location data is generated and cached when a Go Snowflake Driver application starts, and if the given offset is not in the cache, it is generated dynamically. Currently, Snowflake does not support the name-based Location types (e.g. "America/Los_Angeles"). For more information about Location types, see the Go documentation for https://golang.org/pkg/time/#Location. Internally, this feature leverages the []byte data type. As a result, BINARY data cannot be bound without the binding parameter flag. In the following example, sf is an alias for the gosnowflake package: The driver directly downloads a result set from the cloud storage if the size is large. It is required to shift workloads from the Snowflake database to the clients for scale. The download takes place by goroutine named "Chunk Downloader" asynchronously so that the driver can fetch the next result set while the application can consume the current result set. The application may change the number of result set chunk downloader if required. Note this does not help reduce memory footprint by itself. Consider Custom JSON Decoder. Custom JSON Decoder for Parsing Result Set (Experimental) The application may have the driver use a custom JSON decoder that incrementally parses the result set as follows. This option will reduce the memory footprint to half or even quarter, but it can significantly degrade the performance depending on the environment. The test cases running on Travis Ubuntu box show five times less memory footprint while four times slower. Be cautious when using the option. The Go Snowflake Driver supports JWT (JSON Web Token) authentication. To enable this feature, construct the DSN with fields "authenticator=SNOWFLAKE_JWT&privateKey=<your_private_key>", or using a Config structure specifying: The <your_private_key> should be a base64 URL encoded PKCS8 rsa private key string. One way to encode a byte slice to URL base 64 URL format is through the base64.URLEncoding.EncodeToString() function. On the server side, you can alter the public key with the SQL command: The <your_public_key> should be a base64 Standard encoded PKI public key string. One way to encode a byte slice to base 64 Standard format is through the base64.StdEncoding.EncodeToString() function. To generate the valid key pair, you can execute the following commands in the shell: Note: As of February 2020, Golang's official library does not support passcode-encrypted PKCS8 private key. For security purposes, Snowflake highly recommends that you store the passcode-encrypted private key on the disk and decrypt the key in your application using a library you trust. JWT tokens are recreated on each retry and they are valid (`exp` claim) for `jwtTimeout` seconds. Each retry timeout is configured by `jwtClientTimeout`. Retries are limited by total time of `loginTimeout`. The driver allows to authenticate using the external browser. When a connection is created, the driver will open the browser window and ask the user to sign in. To enable this feature, construct the DSN with field "authenticator=EXTERNALBROWSER" or using a Config structure with following Authenticator specified: The external browser authentication implements timeout mechanism. This prevents the driver from hanging interminably when browser window was closed, or not responding. Timeout defaults to 120s and can be changed through setting DSN field "externalBrowserTimeout=240" (time in seconds) or using a Config structure with following ExternalBrowserTimeout specified: This feature is available in version 1.3.8 or later of the driver. By default, Snowflake returns an error for queries issued with multiple statements. This restriction helps protect against SQL Injection attacks (https://en.wikipedia.org/wiki/SQL_injection). The multi-statement feature allows users skip this restriction and execute multiple SQL statements through a single Golang function call. However, this opens up the possibility for SQL injection, so it should be used carefully. The risk can be reduced by specifying the exact number of statements to be executed, which makes it more difficult to inject a statement by appending it. More details are below. The Go Snowflake Driver provides two functions that can execute multiple SQL statements in a single call: To compose a multi-statement query, simply create a string that contains all the queries, separated by semicolons, in the order in which the statements should be executed. To protect against SQL Injection attacks while using the multi-statement feature, pass a Context that specifies the number of statements in the string. For example: When multiple queries are executed by a single call to QueryContext(), multiple result sets are returned. After you process the first result set, get the next result set (for the next SQL statement) by calling NextResultSet(). The following pseudo-code shows how to process multiple result sets: The function db.ExecContext() returns a single result, which is the sum of the number of rows changed by each individual statement. For example, if your multi-statement query executed two UPDATE statements, each of which updated 10 rows, then the result returned would be 20. Individual row counts for individual statements are not available. The following code shows how to retrieve the result of a multi-statement query executed through db.ExecContext(): Note: Because a multi-statement ExecContext() returns a single value, you cannot detect offsetting errors. For example, suppose you expected the return value to be 20 because you expected each UPDATE statement to update 10 rows. If one UPDATE statement updated 15 rows and the other UPDATE statement updated only 5 rows, the total would still be 20. You would see no indication that the UPDATES had not functioned as expected. The ExecContext() function does not return an error if passed a query (e.g. a SELECT statement). However, it still returns only a single value, not a result set, so using it to execute queries (or a mix of queries and non-query statements) is impractical. The QueryContext() function does not return an error if passed non-query statements (e.g. DML). The function returns a result set for each statement, whether or not the statement is a query. For each non-query statement, the result set contains a single row that contains a single column; the value is the number of rows changed by the statement. If you want to execute a mix of query and non-query statements (e.g. a mix of SELECT and DML statements) in a multi-statement query, use QueryContext(). You can retrieve the result sets for the queries, and you can retrieve or ignore the row counts for the non-query statements. Note: PUT statements are not supported for multi-statement queries. If a SQL statement passed to ExecQuery() or QueryContext() fails to compile or execute, that statement is aborted, and subsequent statements are not executed. Any statements prior to the aborted statement are unaffected. For example, if the statements below are run as one multi-statement query, the multi-statement query fails on the third statement, and an exception is thrown. If you then query the contents of the table named "test", the values 1 and 2 would be present. When using the QueryContext() and ExecContext() functions, golang code can check for errors the usual way. For example: Preparing statements and using bind variables are also not supported for multi-statement queries. The Go Snowflake Driver supports asynchronous execution of SQL statements. Asynchronous execution allows you to start executing a statement and then retrieve the result later without being blocked while waiting. While waiting for the result of a SQL statement, you can perform other tasks, including executing other SQL statements. Most of the steps to execute an asynchronous query are the same as the steps to execute a synchronous query. However, there is an additional step, which is that you must call the WithAsyncMode() function to update your Context object to specify that asynchronous mode is enabled. In the code below, the call to "WithAsyncMode()" is specific to asynchronous mode. The rest of the code is compatible with both asynchronous mode and synchronous mode. The function db.QueryContext() returns an object of type snowflakeRows regardless of whether the query is synchronous or asynchronous. However: The call to the Next() function of snowflakeRows is always synchronous (i.e. blocking). If the query has not yet completed and the snowflakeRows object (named "rows" in this example) has not been filled in yet, then rows.Next() waits until the result set has been filled in. More generally, calls to any Golang SQL API function implemented in snowflakeRows or snowflakeResult are blocking calls, and wait if results are not yet available. (Examples of other synchronous calls include: snowflakeRows.Err(), snowflakeRows.Columns(), snowflakeRows.columnTypes(), snowflakeRows.Scan(), and snowflakeResult.RowsAffected().) Because the example code above executes only one query and no other activity, there is no significant difference in behavior between asynchronous and synchronous behavior. The differences become significant if, for example, you want to perform some other activity after the query starts and before it completes. The example code below starts a query, which run in the background, and then retrieves the results later. This example uses small SELECT statements that do not retrieve enough data to require asynchronous handling. However, the technique works for larger data sets, and for situations where the programmer might want to do other work after starting the queries and before retrieving the results. For a more elaborative example please see cmd/async/async.go The Go Snowflake Driver supports the PUT and GET commands. The PUT command copies a file from a local computer (the computer where the Golang client is running) to a stage on the cloud platform. The GET command copies data files from a stage on the cloud platform to a local computer. See the following for information on the syntax and supported parameters: Using PUT: The following example shows how to run a PUT command by passing a string to the db.Query() function: "<local_file>" should include the file path as well as the name. Snowflake recommends using an absolute path rather than a relative path. For example: Different client platforms (e.g. linux, Windows) have different path name conventions. Ensure that you specify path names appropriately. This is particularly important on Windows, which uses the backslash character as both an escape character and as a separator in path names. To send information from a stream (rather than a file) use code similar to the code below. (The ReplaceAll() function is needed on Windows to handle backslashes in the path to the file.) Note: PUT statements are not supported for multi-statement queries. Using GET: The following example shows how to run a GET command by passing a string to the db.Query() function: "<local_file>" should include the file path as well as the name. Snowflake recommends using an absolute path rather than a relative path. For example: To download a file into an in-memory stream (rather than a file) use code similar to the code below. Note: GET statements are not supported for multi-statement queries. Specifying temporary directory for encryption and compression: Putting and getting requires compression and/or encryption, which is done in the OS temporary directory. If you cannot use default temporary directory for your OS or you want to specify it yourself, you can use "tmpDirPath" DSN parameter. Remember, to encode slashes. Example: Using custom configuration for PUT/GET: If you want to override some default configuration options, you can use `WithFileTransferOptions` context. There are multiple config parameters including progress bars or compression.

Package gofpdf implements a PDF document generator with high level support for text, drawing and images. - UTF-8 support - Choice of measurement unit, page format and margins - Page header and footer management - Automatic page breaks, line breaks, and text justification - Inclusion of JPEG, PNG, GIF, TIFF and basic path-only SVG images - Colors, gradients and alpha channel transparency - Outline bookmarks - Internal and external links - TrueType, Type1 and encoding support - Page compression - Lines, Bézier curves, arcs, and ellipses - Rotation, scaling, skewing, translation, and mirroring - Clipping - Document protection - Layers - Templates - Barcodes - Charting facility - Import PDFs as templates gofpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. gofpdf supports UTF-8 TrueType fonts and “right-to-left” languages. Note that Chinese, Japanese, and Korean characters may not be included in many general purpose fonts. For these languages, a specialized font (for example, NotoSansSC for simplified Chinese) can be used. Also, support is provided to automatically translate UTF-8 runes to code page encodings for languages that have fewer than 256 glyphs. This repository will not be maintained, at least for some unknown duration. But it is hoped that gofpdf has a bright future in the open source world. Due to Go’s promise of compatibility, gofpdf should continue to function without modification for a longer time than would be the case with many other languages. Forks should be based on the last viable commit. Tools such as active-forks can be used to select a fork that looks promising for your needs. If a particular fork looks like it has taken the lead in attracting followers, this README will be updated to point people in that direction. The efforts of all contributors to this project have been deeply appreciated. Best wishes to all of you. If you currently use the $GOPATH scheme, install the package with the following command. To test the installation, run The following Go code generates a simple PDF file. See the functions in the fpdf_test.go file (shown as examples in this documentation) for more advanced PDF examples. If an error occurs in an Fpdf method, an internal error field is set. After this occurs, Fpdf method calls typically return without performing any operations and the error state is retained. This error management scheme facilitates PDF generation since individual method calls do not need to be examined for failure; it is generally sufficient to wait until after Output() is called. For the same reason, if an error occurs in the calling application during PDF generation, it may be desirable for the application to transfer the error to the Fpdf instance by calling the SetError() method or the SetErrorf() method. At any time during the life cycle of the Fpdf instance, the error state can be determined with a call to Ok() or Err(). The error itself can be retrieved with a call to Error(). This package is a relatively straightforward translation from the original FPDF library written in PHP (despite the caveat in the introduction to Effective Go). The API names have been retained even though the Go idiom would suggest otherwise (for example, pdf.GetX() is used rather than simply pdf.X()). The similarity of the two libraries makes the original FPDF website a good source of information. It includes a forum and FAQ. However, some internal changes have been made. Page content is built up using buffers (of type bytes.Buffer) rather than repeated string concatenation. Errors are handled as explained above rather than panicking. Output is generated through an interface of type io.Writer or io.WriteCloser. A number of the original PHP methods behave differently based on the type of the arguments that are passed to them; in these cases additional methods have been exported to provide similar functionality. Font definition files are produced in JSON rather than PHP. A side effect of running go test ./... is the production of a number of example PDFs. These can be found in the gofpdf/pdf directory after the tests complete. Please note that these examples run in the context of a test. In order run an example as a standalone application, you’ll need to examine fpdf_test.go for some helper routines, for example exampleFilename() and summary(). Example PDFs can be compared with reference copies in order to verify that they have been generated as expected. This comparison will be performed if a PDF with the same name as the example PDF is placed in the gofpdf/pdf/reference directory and if the third argument to ComparePDFFiles() in internal/example/example.go is true. (By default it is false.) The routine that summarizes an example will look for this file and, if found, will call ComparePDFFiles() to check the example PDF for equality with its reference PDF. If differences exist between the two files they will be printed to standard output and the test will fail. If the reference file is missing, the comparison is considered to succeed. In order to successfully compare two PDFs, the placement of internal resources must be consistent and the internal creation timestamps must be the same. To do this, the methods SetCatalogSort() and SetCreationDate() need to be called for both files. This is done automatically for all examples. Nothing special is required to use the standard PDF fonts (courier, helvetica, times, zapfdingbats) in your documents other than calling SetFont(). You should use AddUTF8Font() or AddUTF8FontFromBytes() to add a TrueType UTF-8 encoded font. Use RTL() and LTR() methods switch between “right-to-left” and “left-to-right” mode. In order to use a different non-UTF-8 TrueType or Type1 font, you will need to generate a font definition file and, if the font will be embedded into PDFs, a compressed version of the font file. This is done by calling the MakeFont function or using the included makefont command line utility. To create the utility, cd into the makefont subdirectory and run “go build”. This will produce a standalone executable named makefont. Select the appropriate encoding file from the font subdirectory and run the command as in the following example. In your PDF generation code, call AddFont() to load the font and, as with the standard fonts, SetFont() to begin using it. Most examples, including the package example, demonstrate this method. Good sources of free, open-source fonts include Google Fonts and DejaVu Fonts. The draw2d package is a two dimensional vector graphics library that can generate output in different forms. It uses gofpdf for its document production mode. gofpdf is a global community effort and you are invited to make it even better. If you have implemented a new feature or corrected a problem, please consider contributing your change to the project. A contribution that does not directly pertain to the core functionality of gofpdf should be placed in its own directory directly beneath the contrib directory. Here are guidelines for making submissions. Your change should - be compatible with the MIT License - be properly documented - be formatted with go fmt - include an example in fpdf_test.go if appropriate - conform to the standards of golint and go vet, that is, golint . and go vet . should not generate any warnings - not diminish test coverage Pull requests are the preferred means of accepting your changes. gofpdf is released under the MIT License. It is copyrighted by Kurt Jung and the contributors acknowledged below. This package’s code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Bruno Michel has provided valuable assistance with the code. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF transparency script by Martin Hall-May. Support for gradients and clipping is adapted from FPDF scripts by Andreas Würmser. Support for outline bookmarks is adapted from Olivier Plathey by Manuel Cornes. Layer support is adapted from Olivier Plathey. Support for transformations is adapted from the FPDF transformation script by Moritz Wagner and Andreas Würmser. PDF protection is adapted from the work of Klemen Vodopivec for the FPDF product. Lawrence Kesteloot provided code to allow an image’s extent to be determined prior to placement. Support for vertical alignment within a cell was provided by Stefan Schroeder. Ivan Daniluk generalized the font and image loading code to use the Reader interface while maintaining backward compatibility. Anthony Starks provided code for the Polygon function. Robert Lillack provided the Beziergon function and corrected some naming issues with the internal curve function. Claudio Felber provided implementations for dashed line drawing and generalized font loading. Stani Michiels provided support for multi-segment path drawing with smooth line joins, line join styles, enhanced fill modes, and has helped greatly with package presentation and tests. Templating is adapted by Marcus Downing from the FPDF_Tpl library created by Jan Slabon and Setasign. Jelmer Snoeck contributed packages that generate a variety of barcodes and help with registering images on the web. Jelmer Snoek and Guillermo Pascual augmented the basic HTML functionality with aligned text. Kent Quirk implemented backwards-compatible support for reading DPI from images that support it, and for setting DPI manually and then having it properly taken into account when calculating image size. Paulo Coutinho provided support for static embedded fonts. Dan Meyers added support for embedded JavaScript. David Fish added a generic alias-replacement function to enable, among other things, table of contents functionality. Andy Bakun identified and corrected a problem in which the internal catalogs were not sorted stably. Paul Montag added encoding and decoding functionality for templates, including images that are embedded in templates; this allows templates to be stored independently of gofpdf. Paul also added support for page boxes used in printing PDF documents. Wojciech Matusiak added supported for word spacing. Artem Korotkiy added support of UTF-8 fonts. Dave Barnes added support for imported objects and templates. Brigham Thompson added support for rounded rectangles. Joe Westcott added underline functionality and optimized image storage. Benoit KUGLER contributed support for rectangles with corners of unequal radius, modification times, and for file attachments and annotations. - Remove all legacy code page font support; use UTF-8 exclusively - Improve test coverage as reported by the coverage tool. Example demonstrates the generation of a simple PDF document. Note that since only core fonts are used (in this case Arial, a synonym for Helvetica), an empty string can be specified for the font directory in the call to New(). Note also that the example.Filename() and example.Summary() functions belong to a separate, internal package and are not part of the gofpdf library. If an error occurs at some point during the construction of the document, subsequent method calls exit immediately and the error is finally retrieved with the output call where it can be handled by the application.

Package aw is a "plug-and-play" workflow development library/framework for Alfred 3 & 4 (https://www.alfredapp.com/). It requires Go 1.13 or later. It provides everything you need to create a polished and blazing-fast Alfred frontend for your project. As of AwGo 0.26, all applicable features of Alfred 4.1 are supported. The main features are: AwGo is an opinionated framework that expects to be used in a certain way in order to eliminate boilerplate. It *will* panic if not run in a valid, minimally Alfred-like environment. At a minimum the following environment variables should be set to meaningful values: NOTE: AwGo is currently in development. The API *will* change and should not be considered stable until v1.0. Until then, be sure to pin a version using go modules or similar. Be sure to also check out the _examples/ subdirectory, which contains some simple, but complete, workflows that demonstrate the features of AwGo and useful workflow idioms. Typically, you'd call your program's main entry point via Workflow.Run(). This way, the library will rescue any panic, log the stack trace and show an error message to the user in Alfred. In the Script box (Language = "/bin/bash"): To generate results for Alfred to show in a Script Filter, use the feedback API of Workflow: You can set workflow variables (via feedback) with Workflow.Var, Item.Var and Modifier.Var. See Workflow.SendFeedback for more documentation. Alfred requires a different JSON format if you wish to set workflow variables. Use the ArgVars (named for its equivalent element in Alfred) struct to generate output from Run Script actions. Be sure to set TextErrors to true to prevent Workflow from generating Alfred JSON if it catches a panic: See ArgVars for more information. New() creates a *Workflow using the default values and workflow settings read from environment variables set by Alfred. You can change defaults by passing one or more Options to New(). If you do not want to use Alfred's environment variables, or they aren't set (i.e. you're not running the code in Alfred), use NewFromEnv() with a custom Env implementation. A Workflow can be re-configured later using its Configure() method. See the documentation for Option for more information on configuring a Workflow. AwGo can check for and install new versions of your workflow. Subpackage update provides an implementation of the Updater interface and sources to load updates from GitHub or Gitea releases, or from the URL of an Alfred `metadata.json` file. See subpackage update and _examples/update. AwGo can filter Script Filter feedback using a Sublime Text-like fuzzy matching algorithm. Workflow.Filter() sorts feedback Items against the provided query, removing those that do not match. See _examples/fuzzy for a basic demonstration, and _examples/bookmarks for a demonstration of implementing fuzzy.Sortable on your own structs and customising the fuzzy sort settings. Fuzzy matching is done by package https://godoc.org/go.deanishe.net/fuzzy AwGo automatically configures the default log package to write to STDERR (Alfred's debugger) and a log file in the workflow's cache directory. The log file is necessary because background processes aren't connected to Alfred, so their output is only visible in the log. It is rotated when it exceeds 1 MiB in size. One previous log is kept. AwGo detects when Alfred's debugger is open (Workflow.Debug() returns true) and in this case prepends filename:linenumber: to log messages. The Config struct (which is included in Workflow as Workflow.Config) provides an interface to the workflow's settings from the Workflow Environment Variables panel (see https://www.alfredapp.com/help/workflows/advanced/variables/#environment). Alfred exports these settings as environment variables, and you can read them ad-hoc with the Config.Get*() methods, and save values back to Alfred/info.plist with Config.Set(). Using Config.To() and Config.From(), you can "bind" your own structs to the settings in Alfred: See the documentation for Config.To and Config.From for more information, and _examples/settings for a demo workflow based on the API. The Alfred struct provides methods for the rest of Alfred's AppleScript API. Amongst other things, you can use it to tell Alfred to open, to search for a query, to browse/action files & directories, or to run External Triggers. See documentation of the Alfred struct for more information. AwGo provides a basic, but useful, API for loading and saving data. In addition to reading/writing bytes and marshalling/unmarshalling to/from JSON, the API can auto-refresh expired cache data. See Cache and Session for the API documentation. Workflow has three caches tied to different directories: These all share (almost) the same API. The difference is in when the data go away. Data saved with Session are deleted after the user closes Alfred or starts using a different workflow. The Cache directory is in a system cache directory, so may be deleted by the system or "system maintenance" tools. The Data directory lives with Alfred's application data and would not normally be deleted. Subpackage util provides several functions for running script files and snippets of AppleScript/JavaScript code. See util for documentation and examples. AwGo offers a simple API to start/stop background processes via Workflow's RunInBackground(), IsRunning() and Kill() methods. This is useful for running checks for updates and other jobs that hit the network or take a significant amount of time to complete, allowing you to keep your Script Filters extremely responsive. See _examples/update and _examples/workflows for demonstrations of this API.

Package gofpdf implements a PDF document generator with high level support for text, drawing and images. - UTF-8 support - Choice of measurement unit, page format and margins - Page header and footer management - Automatic page breaks, line breaks, and text justification - Inclusion of JPEG, PNG, GIF, TIFF and basic path-only SVG images - Colors, gradients and alpha channel transparency - Outline bookmarks - Internal and external links - TrueType, Type1 and encoding support - Page compression - Lines, Bézier curves, arcs, and ellipses - Rotation, scaling, skewing, translation, and mirroring - Clipping - Document protection - Layers - Templates - Barcodes - Charting facility - Import PDFs as templates gofpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. gofpdf supports UTF-8 TrueType fonts and “right-to-left” languages. Note that Chinese, Japanese, and Korean characters may not be included in many general purpose fonts. For these languages, a specialized font (for example, NotoSansSC for simplified Chinese) can be used. Also, support is provided to automatically translate UTF-8 runes to code page encodings for languages that have fewer than 256 glyphs. This repository will not be maintained, at least for some unknown duration. But it is hoped that gofpdf has a bright future in the open source world. Due to Go’s promise of compatibility, gofpdf should continue to function without modification for a longer time than would be the case with many other languages. Forks should be based on the last viable commit. Tools such as active-forks can be used to select a fork that looks promising for your needs. If a particular fork looks like it has taken the lead in attracting followers, this README will be updated to point people in that direction. The efforts of all contributors to this project have been deeply appreciated. Best wishes to all of you. To install the package on your system, run Later, to receive updates, run The following Go code generates a simple PDF file. See the functions in the fpdf_test.go file (shown as examples in this documentation) for more advanced PDF examples. If an error occurs in an Fpdf method, an internal error field is set. After this occurs, Fpdf method calls typically return without performing any operations and the error state is retained. This error management scheme facilitates PDF generation since individual method calls do not need to be examined for failure; it is generally sufficient to wait until after Output() is called. For the same reason, if an error occurs in the calling application during PDF generation, it may be desirable for the application to transfer the error to the Fpdf instance by calling the SetError() method or the SetErrorf() method. At any time during the life cycle of the Fpdf instance, the error state can be determined with a call to Ok() or Err(). The error itself can be retrieved with a call to Error(). This package is a relatively straightforward translation from the original FPDF library written in PHP (despite the caveat in the introduction to Effective Go). The API names have been retained even though the Go idiom would suggest otherwise (for example, pdf.GetX() is used rather than simply pdf.X()). The similarity of the two libraries makes the original FPDF website a good source of information. It includes a forum and FAQ. However, some internal changes have been made. Page content is built up using buffers (of type bytes.Buffer) rather than repeated string concatenation. Errors are handled as explained above rather than panicking. Output is generated through an interface of type io.Writer or io.WriteCloser. A number of the original PHP methods behave differently based on the type of the arguments that are passed to them; in these cases additional methods have been exported to provide similar functionality. Font definition files are produced in JSON rather than PHP. A side effect of running go test ./... is the production of a number of example PDFs. These can be found in the gofpdf/pdf directory after the tests complete. Please note that these examples run in the context of a test. In order run an example as a standalone application, you’ll need to examine fpdf_test.go for some helper routines, for example exampleFilename() and summary(). Example PDFs can be compared with reference copies in order to verify that they have been generated as expected. This comparison will be performed if a PDF with the same name as the example PDF is placed in the gofpdf/pdf/reference directory and if the third argument to ComparePDFFiles() in internal/example/example.go is true. (By default it is false.) The routine that summarizes an example will look for this file and, if found, will call ComparePDFFiles() to check the example PDF for equality with its reference PDF. If differences exist between the two files they will be printed to standard output and the test will fail. If the reference file is missing, the comparison is considered to succeed. In order to successfully compare two PDFs, the placement of internal resources must be consistent and the internal creation timestamps must be the same. To do this, the methods SetCatalogSort() and SetCreationDate() need to be called for both files. This is done automatically for all examples. Nothing special is required to use the standard PDF fonts (courier, helvetica, times, zapfdingbats) in your documents other than calling SetFont(). You should use AddUTF8Font() or AddUTF8FontFromBytes() to add a TrueType UTF-8 encoded font. Use RTL() and LTR() methods switch between “right-to-left” and “left-to-right” mode. In order to use a different non-UTF-8 TrueType or Type1 font, you will need to generate a font definition file and, if the font will be embedded into PDFs, a compressed version of the font file. This is done by calling the MakeFont function or using the included makefont command line utility. To create the utility, cd into the makefont subdirectory and run “go build”. This will produce a standalone executable named makefont. Select the appropriate encoding file from the font subdirectory and run the command as in the following example. In your PDF generation code, call AddFont() to load the font and, as with the standard fonts, SetFont() to begin using it. Most examples, including the package example, demonstrate this method. Good sources of free, open-source fonts include Google Fonts and DejaVu Fonts. The draw2d package is a two dimensional vector graphics library that can generate output in different forms. It uses gofpdf for its document production mode. gofpdf is a global community effort and you are invited to make it even better. If you have implemented a new feature or corrected a problem, please consider contributing your change to the project. A contribution that does not directly pertain to the core functionality of gofpdf should be placed in its own directory directly beneath the contrib directory. Here are guidelines for making submissions. Your change should - be compatible with the MIT License - be properly documented - be formatted with go fmt - include an example in fpdf_test.go if appropriate - conform to the standards of golint and go vet, that is, golint . and go vet . should not generate any warnings - not diminish test coverage Pull requests are the preferred means of accepting your changes. gofpdf is released under the MIT License. It is copyrighted by Kurt Jung and the contributors acknowledged below. This package’s code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Bruno Michel has provided valuable assistance with the code. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF transparency script by Martin Hall-May. Support for gradients and clipping is adapted from FPDF scripts by Andreas Würmser. Support for outline bookmarks is adapted from Olivier Plathey by Manuel Cornes. Layer support is adapted from Olivier Plathey. Support for transformations is adapted from the FPDF transformation script by Moritz Wagner and Andreas Würmser. PDF protection is adapted from the work of Klemen Vodopivec for the FPDF product. Lawrence Kesteloot provided code to allow an image’s extent to be determined prior to placement. Support for vertical alignment within a cell was provided by Stefan Schroeder. Ivan Daniluk generalized the font and image loading code to use the Reader interface while maintaining backward compatibility. Anthony Starks provided code for the Polygon function. Robert Lillack provided the Beziergon function and corrected some naming issues with the internal curve function. Claudio Felber provided implementations for dashed line drawing and generalized font loading. Stani Michiels provided support for multi-segment path drawing with smooth line joins, line join styles, enhanced fill modes, and has helped greatly with package presentation and tests. Templating is adapted by Marcus Downing from the FPDF_Tpl library created by Jan Slabon and Setasign. Jelmer Snoeck contributed packages that generate a variety of barcodes and help with registering images on the web. Jelmer Snoek and Guillermo Pascual augmented the basic HTML functionality with aligned text. Kent Quirk implemented backwards-compatible support for reading DPI from images that support it, and for setting DPI manually and then having it properly taken into account when calculating image size. Paulo Coutinho provided support for static embedded fonts. Dan Meyers added support for embedded JavaScript. David Fish added a generic alias-replacement function to enable, among other things, table of contents functionality. Andy Bakun identified and corrected a problem in which the internal catalogs were not sorted stably. Paul Montag added encoding and decoding functionality for templates, including images that are embedded in templates; this allows templates to be stored independently of gofpdf. Paul also added support for page boxes used in printing PDF documents. Wojciech Matusiak added supported for word spacing. Artem Korotkiy added support of UTF-8 fonts. Dave Barnes added support for imported objects and templates. Brigham Thompson added support for rounded rectangles. Joe Westcott added underline functionality and optimized image storage. Benoit KUGLER contributed support for rectangles with corners of unequal radius, modification times, and for file attachments and annotations. - Remove all legacy code page font support; use UTF-8 exclusively - Improve test coverage as reported by the coverage tool. Example demonstrates the generation of a simple PDF document. Note that since only core fonts are used (in this case Arial, a synonym for Helvetica), an empty string can be specified for the font directory in the call to New(). Note also that the example.Filename() and example.Summary() functions belong to a separate, internal package and are not part of the gofpdf library. If an error occurs at some point during the construction of the document, subsequent method calls exit immediately and the error is finally retrieved with the output call where it can be handled by the application.

Package fpdf implements a PDF document generator with high level support for text, drawing and images. - UTF-8 support - Choice of measurement unit, page format and margins - Page header and footer management - Automatic page breaks, line breaks, and text justification - Inclusion of JPEG, PNG, GIF, TIFF and basic path-only SVG images - Colors, gradients and alpha channel transparency - Outline bookmarks - Internal and external links - TrueType, Type1 and encoding support - Page compression - Lines, Bézier curves, arcs, and ellipses - Rotation, scaling, skewing, translation, and mirroring - Clipping - Document protection - Layers - Templates - Barcodes - Charting facility - Import PDFs as templates go-pdf/fpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. go-pdf/fpdf supports UTF-8 TrueType fonts and “right-to-left” languages. Note that Chinese, Japanese, and Korean characters may not be included in many general purpose fonts. For these languages, a specialized font (for example, NotoSansSC for simplified Chinese) can be used. Also, support is provided to automatically translate UTF-8 runes to code page encodings for languages that have fewer than 256 glyphs. To install the package on your system, run Later, to receive updates, run The following Go code generates a simple PDF file. See the functions in the fpdf_test.go file (shown as examples in this documentation) for more advanced PDF examples. If an error occurs in an Fpdf method, an internal error field is set. After this occurs, Fpdf method calls typically return without performing any operations and the error state is retained. This error management scheme facilitates PDF generation since individual method calls do not need to be examined for failure; it is generally sufficient to wait until after Output() is called. For the same reason, if an error occurs in the calling application during PDF generation, it may be desirable for the application to transfer the error to the Fpdf instance by calling the SetError() method or the SetErrorf() method. At any time during the life cycle of the Fpdf instance, the error state can be determined with a call to Ok() or Err(). The error itself can be retrieved with a call to Error(). This package is a relatively straightforward translation from the original FPDF library written in PHP (despite the caveat in the introduction to Effective Go). The API names have been retained even though the Go idiom would suggest otherwise (for example, pdf.GetX() is used rather than simply pdf.X()). The similarity of the two libraries makes the original FPDF website a good source of information. It includes a forum and FAQ. However, some internal changes have been made. Page content is built up using buffers (of type bytes.Buffer) rather than repeated string concatenation. Errors are handled as explained above rather than panicking. Output is generated through an interface of type io.Writer or io.WriteCloser. A number of the original PHP methods behave differently based on the type of the arguments that are passed to them; in these cases additional methods have been exported to provide similar functionality. Font definition files are produced in JSON rather than PHP. A side effect of running go test ./... is the production of a number of example PDFs. These can be found in the go-pdf/fpdf/pdf directory after the tests complete. Please note that these examples run in the context of a test. In order run an example as a standalone application, you’ll need to examine fpdf_test.go for some helper routines, for example exampleFilename() and summary(). Example PDFs can be compared with reference copies in order to verify that they have been generated as expected. This comparison will be performed if a PDF with the same name as the example PDF is placed in the go-pdf/fpdf/pdf/reference directory and if the third argument to ComparePDFFiles() in internal/example/example.go is true. (By default it is false.) The routine that summarizes an example will look for this file and, if found, will call ComparePDFFiles() to check the example PDF for equality with its reference PDF. If differences exist between the two files they will be printed to standard output and the test will fail. If the reference file is missing, the comparison is considered to succeed. In order to successfully compare two PDFs, the placement of internal resources must be consistent and the internal creation timestamps must be the same. To do this, the methods SetCatalogSort() and SetCreationDate() need to be called for both files. This is done automatically for all examples. Nothing special is required to use the standard PDF fonts (courier, helvetica, times, zapfdingbats) in your documents other than calling SetFont(). You should use AddUTF8Font() or AddUTF8FontFromBytes() to add a TrueType UTF-8 encoded font. Use RTL() and LTR() methods switch between “right-to-left” and “left-to-right” mode. In order to use a different non-UTF-8 TrueType or Type1 font, you will need to generate a font definition file and, if the font will be embedded into PDFs, a compressed version of the font file. This is done by calling the MakeFont function or using the included makefont command line utility. To create the utility, cd into the makefont subdirectory and run “go build”. This will produce a standalone executable named makefont. Select the appropriate encoding file from the font subdirectory and run the command as in the following example. In your PDF generation code, call AddFont() to load the font and, as with the standard fonts, SetFont() to begin using it. Most examples, including the package example, demonstrate this method. Good sources of free, open-source fonts include Google Fonts and DejaVu Fonts. The draw2d package is a two dimensional vector graphics library that can generate output in different forms. It uses gofpdf for its document production mode. gofpdf is a global community effort and you are invited to make it even better. If you have implemented a new feature or corrected a problem, please consider contributing your change to the project. A contribution that does not directly pertain to the core functionality of gofpdf should be placed in its own directory directly beneath the contrib directory. Here are guidelines for making submissions. Your change should - be compatible with the MIT License - be properly documented - be formatted with go fmt - include an example in fpdf_test.go if appropriate - conform to the standards of golint and go vet, that is, golint . and go vet . should not generate any warnings - not diminish test coverage Pull requests are the preferred means of accepting your changes. gofpdf is released under the MIT License. It is copyrighted by Kurt Jung and the contributors acknowledged below. This package’s code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Bruno Michel has provided valuable assistance with the code. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF transparency script by Martin Hall-May. Support for gradients and clipping is adapted from FPDF scripts by Andreas Würmser. Support for outline bookmarks is adapted from Olivier Plathey by Manuel Cornes. Layer support is adapted from Olivier Plathey. Support for transformations is adapted from the FPDF transformation script by Moritz Wagner and Andreas Würmser. PDF protection is adapted from the work of Klemen Vodopivec for the FPDF product. Lawrence Kesteloot provided code to allow an image’s extent to be determined prior to placement. Support for vertical alignment within a cell was provided by Stefan Schroeder. Ivan Daniluk generalized the font and image loading code to use the Reader interface while maintaining backward compatibility. Anthony Starks provided code for the Polygon function. Robert Lillack provided the Beziergon function and corrected some naming issues with the internal curve function. Claudio Felber provided implementations for dashed line drawing and generalized font loading. Stani Michiels provided support for multi-segment path drawing with smooth line joins, line join styles, enhanced fill modes, and has helped greatly with package presentation and tests. Templating is adapted by Marcus Downing from the FPDF_Tpl library created by Jan Slabon and Setasign. Jelmer Snoeck contributed packages that generate a variety of barcodes and help with registering images on the web. Jelmer Snoek and Guillermo Pascual augmented the basic HTML functionality with aligned text. Kent Quirk implemented backwards-compatible support for reading DPI from images that support it, and for setting DPI manually and then having it properly taken into account when calculating image size. Paulo Coutinho provided support for static embedded fonts. Dan Meyers added support for embedded JavaScript. David Fish added a generic alias-replacement function to enable, among other things, table of contents functionality. Andy Bakun identified and corrected a problem in which the internal catalogs were not sorted stably. Paul Montag added encoding and decoding functionality for templates, including images that are embedded in templates; this allows templates to be stored independently of gofpdf. Paul also added support for page boxes used in printing PDF documents. Wojciech Matusiak added supported for word spacing. Artem Korotkiy added support of UTF-8 fonts. Dave Barnes added support for imported objects and templates. Brigham Thompson added support for rounded rectangles. Joe Westcott added underline functionality and optimized image storage. Benoit KUGLER contributed support for rectangles with corners of unequal radius, modification times, and for file attachments and annotations. - Remove all legacy code page font support; use UTF-8 exclusively - Improve test coverage as reported by the coverage tool. Example demonstrates the generation of a simple PDF document. Note that since only core fonts are used (in this case Arial, a synonym for Helvetica), an empty string can be specified for the font directory in the call to New(). Note also that the example.Filename() and example.SummaryCompare() functions belong to a separate, internal package and are not part of the gofpdf library. If an error occurs at some point during the construction of the document, subsequent method calls exit immediately and the error is finally retrieved with the output call where it can be handled by the application.

stackblur-go is a Go port of the Stackblur algorithm. Stackblur is a compromise between Gaussian blur and Box blur, but it creates much better looking blurs than Box blur and it is ~7x faster than Gaussian blur. The API is very simple and easy to integrate into the project. There is a single publicly exposed `Process` functions which receive an image and a radius as parameters and returns the blurred version of the provided image. Below is a very simple example of how you can use this package.

Package duit is a pure go, cross-platform, MIT-licensed, UI toolkit for developers. The examples/ directory has small code examples for working with duit and its UIs. Examples are the recommended starting point. Start with NewDUI to create a DUI: essentially a window and all the UI state. The user interface consists of a hierarchy of "UIs" like Box, Scroll, Button, Label, etc. They are called UIs, after the interface UI they all implement. The zero structs for UIs have sane default behaviour so you only have to fill in the fields you need. UIs are kept/wrapped in a Kid, to track their layout/draw state. Use NewKids() to build up the UIs for your application. You won't see much of the Kid-types/functions otherwise, unless you implement a new UI. You are in charge of the main event loop, receiving mouse/keyboard/window events from the dui.Inputs channel, and typically passing them on unchanged to dui.Input. All callbacks and functions on UIs are called from inside dui.Input. From there you can also safely change the the UIs, no locking required. After changing a UI you are responsible for calling MarkLayout or MarkDraw to tell duit the UI needs a new layout or draw. This may sound like more work, but this tradeoff keeps the API small and easy to use. If you need to change the UI from a goroutine outside of the main loop, e.g. for blocking calls, you can send a function that makes those modifications on the dui.Call channel, which will be run on the main channel through dui.Inputs. After handling an input, duit will layout or draw as necessary, no need to render explicitly. Embedding a UI into your own data structure is often an easy way to build up UI hiearchies. Scroll and Edit show a scrollbar. Use button 1 on the scrollbar to scroll up, button 3 to scroll down. If you click more near the top, you scroll less. More near the bottom, more. Button 2 scrolls to the absolute place, where you clicked. Button 4 and 5 are wheel up and wheel down, and also scroll less/more depending on position in the UI.

Package girc provides a high level, yet flexible IRC library for use with interacting with IRC servers. girc has support for user/channel tracking, as well as a few other neat features (like auto-reconnect). Much of what girc can do, can also be disabled. The goal is to provide a solid API that you don't necessarily have to work with out of the box if you don't want to. See the examples below for a few brief and useful snippets taking advantage of girc, which should give you a general idea of how the API works. The bare-minimum needed to get started with girc. Just connects and idles. Another basic example, however with this, we add simple !<command> responses to things. E.g. "!hello", "!stop", and "!restart". Very simple example that connects, joins a channel, and responds to "hello" with "hello world!".

Package cninfra is the parent package for all packages that are parts of the CN-Infra platform - a Golang platform for building cloud-native microservices. The CN-Infra platform is a modular platform comprising a core and a set of plugins. The core provides lifecycle management for plugins, the plugins provide the functionality of the platform. A plugin can consist of one or more Golang packages. Out of the box, the CN-Infra platform provides reusable plugins for logging, health checks, messaging (e.g. Kafka), a common front-end API and back-end connectivity to various data stores (Etcd, Cassandra, Redis, ...), and REST and gRPC APIs. The CN-Infra platform can be extended by adding a new platform plugin, for example a new data store client or a message bus adapter. Also, each application built on top of the platform is basically just a set of application-specific plugins.

Package cninfra is the parent package for all packages that are parts of the CN-Infra platform - a Golang platform for building cloud-native microservices. The CN-Infra platform is a modular platform comprising a core and a set of plugins. The core provides lifecycle management for plugins, the plugins provide the functionality of the platform. A plugin can consist of one or more Golang packages. Out of the box, the CN-Infra platform provides reusable plugins for logging, health checks, messaging (e.g. Kafka), a common front-end API and back-end connectivity to various data stores (Etcd, Cassandra, Redis, ...), and REST and gRPC APIs. The CN-Infra platform can be extended by adding a new platform plugin, for example a new data store client or a message bus adapter. Also, each application built on top of the platform is basically just a set of application-specific plugins.

Package sodium is a wrapper for https://github.com/jedisct1/libsodium Most of the functions is a method to the "Bytes" type. They are grouped below: Sender sign a message with its SecretKey and the receiver can verify the Signature by sender's PublicKey (Ed25519) (Ed25519ph) An anonymous can encrypt a message with an ephemeral key pair and reveiver's PublicKey. The receiver can decrypt the message with its SecretKey. Only the receiver is authenticated. (X25519-XSalsa20-Poly1305) Authenticated Box can be used to pass encrypt message from a known sender to a known receiver. The sender and the receiver are both authenticated to each other. A one-time shared nonce is also generated and passed to protect the key pairs and messages. (X25519-XSalsa20-Poly1305) Server and Client exchange their public key and calculates a common session key with their own secret key. (rx || tx = BLAKE2B-512(p.n || client_pk || server_pk)) One holder of a secret key authenticates the message with MAC. (HMAC-SHA512256) Use a secret key and a nonce to protect the key, messages could be encrypted into a SecretBox. The encrypted data's intergrity is checked when decryption. (XSalsa20-Poly1305) Use a secret key and a nonce to protect the key, messages could be encrypted. Optional additional data and the message is authenticited with an authentication tag. Both intergrity and authenticity is checked when decryption. The decryption would not be performed unless the authentication tag is verified. AEADCP* (ChaCha20-Poly1305_IETF) AEADXCP* (XChaCha20-Poly1305_IETF) High-level streaming API that use AEAD construct. Using `SecretStreamTag_Sync` to indicate the end of message. And this is useful for application to parse the message earlier. Rekeying is automatic. However using `SecretStreamTag_Rekey` explicitly ask for rekeying. Typical usage is sending chunks with `SecretStreamTag_Message`. XCP (XChaCha20-Poly1305_IETF) Deriving subkeys from a single high-entropy key KDF (BLAKE2B)

Package siris is a fully-featured HTTP/2 backend web framework written entirely in Google’s Go Language. Source code and other details for the project are available at GitHub: The only requirement is the Go Programming Language, at least version 1.8 Example code: Access to all hosts that serve your application can be provided by the `Application#Hosts` field, after the `Run` method. But the most common scenario is that you may need access to the host before the `Run` method, there are two ways of gain access to the host supervisor, read below. First way is to use the `app.NewHost` to create a new host and use one of its `Serve` or `Listen` functions to start the application via the `siris#Raw` Runner. Note that this way needs an extra import of the `net/http` package. Example Code: Second, and probably easier way is to use the `host.Configurator`. Note that this method requires an extra import statement of "github.com/go-siris/siris/core/host" when using go < 1.9, if you're targeting on go1.9 then you can use the `siris#Supervisor` and omit the extra host import. All common `Runners` we saw earlier (`siris#Addr, siris#Listener, siris#Server, siris#TLS, siris#AutoTLS`) accept a variadic argument of `host.Configurator`, there are just `func(*host.Supervisor)`. Therefore the `Application` gives you the rights to modify the auto-created host supervisor through these. Example Code: All HTTP methods are supported, developers can also register handlers for same paths for different methods. The first parameter is the HTTP Method, second parameter is the request path of the route, third variadic parameter should contains one or more context.Handler executed by the registered order when a user requests for that specific resouce path from the server. Example code: In order to make things easier for the user, Siris provides functions for all HTTP Methods. The first parameter is the request path of the route, second variadic parameter should contains one or more context.Handler executed by the registered order when a user requests for that specific resouce path from the server. Example code: A set of routes that are being groupped by path prefix can (optionally) share the same middleware handlers and template layout. A group can have a nested group too. `.Party` is being used to group routes, developers can declare an unlimited number of (nested) groups. Example code: Siris developers are able to register their own handlers for http statuses like 404 not found, 500 internal server error and so on. Example code: With the help of Siris's expressionist router you can build any form of API you desire, with safety. Example code: At the previous example, we've seen static routes, group of routes, subdomains, wildcard subdomains, a small example of parameterized path with a single known paramete and custom http errors, now it's time to see wildcard parameters and macros. Siris, like net/http std package registers route's handlers by a Handler, the Siris' type of handler is just a func(ctx context.Context) where context comes from github.com/go-siris/siris/context. Until go 1.9 you will have to import that package too, after go 1.9 this will be not be necessary. Siris has the easiest and the most powerful routing process you have ever meet. At the same time, Siris has its own interpeter(yes like a programming language) for route's path syntax and their dynamic path parameters parsing and evaluation, I am calling them "macros" for shortcut. How? It calculates its needs and if not any special regexp needed then it just registers the route with the low-level path syntax, otherwise it pre-compiles the regexp and adds the necessary middleware(s). Standard macro types for parameters: if type is missing then parameter's type is defaulted to string, so {param} == {param:string}. If a function not found on that type then the "string"'s types functions are being used. i.e: Besides the fact that Siris provides the basic types and some default "macro funcs" you are able to register your own too!. Register a named path parameter function: at the func(argument ...) you can have any standard type, it will be validated before the server starts so don't care about performance here, the only thing it runs at serve time is the returning func(paramValue string) bool. Example code: A path parameter name should contain only alphabetical letters, symbols, containing '_' and numbers are NOT allowed. If route failed to be registered, the app will panic without any warnings if you didn't catch the second return value(error) on .Handle/.Get.... Last, do not confuse ctx.Values() with ctx.Params(). Path parameter's values goes to ctx.Params() and context's local storage that can be used to communicate between handlers and middleware(s) goes to ctx.Values(), path parameters and the rest of any custom values are separated for your own good. Run Static Files Example code: More examples can be found here: https://github.com/go-siris/siris/tree/master/_examples/beginner/file-server Middleware is just a concept of ordered chain of handlers. Middleware can be registered globally, per-party, per-subdomain and per-route. Example code: Siris is able to wrap and convert any external, third-party Handler you used to use to your web application. Let's convert the https://github.com/rs/cors net/http external middleware which returns a `next form` handler. Example code: Siris supports 5 template engines out-of-the-box, developers can still use any external golang template engine, as `context.ResponseWriter()` is an `io.Writer`. All of these five template engines have common features with common API, like Layout, Template Funcs, Party-specific layout, partial rendering and more. Example code: View engine supports bundled(https://github.com/jteeuwen/go-bindata) template files too. go-bindata gives you two functions, asset and assetNames, these can be set to each of the template engines using the `.Binary` func. Example code: A real example can be found here: https://github.com/go-siris/siris/tree/master/_examples/intermediate/view/embedding-templates-into-app. Enable auto-reloading of templates on each request. Useful while developers are in dev mode as they no neeed to restart their app on every template edit. Example code: Each one of these template engines has different options located here: https://github.com/go-siris/siris/tree/master/view . This example will show how to store and access data from a session. You don’t need any third-party library, but If you want you can use any session manager compatible or not. In this example we will only allow authenticated users to view our secret message on the /secret page. To get access to it, the will first have to visit /login to get a valid session cookie, which logs him in. Additionally he can visit /logout to revoke his access to our secret message. Example code: Running the example: But you should have a basic idea of the framework by now, we just scratched the surface. If you enjoy what you just saw and want to learn more, please follow the below links: Examples: Built'n Middleware: Community Middleware: Home Page:

Package heroku is a client interface to the Heroku API. This package provides a complete interface to all of the Heroku Platform API v3 actions, and is almost entirely auto-generated based on the API's JSON Schema. The exceptions are the files heroku.go, heroku_test.go, and app_test.go, as well as the generator itself. All models are auto-generated by the Ruby script in gen/gen.rb. The client leverages Go's powerful net/http Client. That means that, out-of-the-box, it has keep-alive support and the ability to handle many concurrent requests from different goroutines. You should have at least some understanding of Heroku and its Platform API: https://devcenter.heroku.com/articles/platform-api-reference This package is targeted towards Go 1.2 or later, though it may work on earlier versions as well. Run `go get github.com/bgentry/heroku-go` to download, build, and install the package. To use the client, first add it to your Go file's imports list: Then create a Client object and make calls to it: That's it! Here is a more advanced example that also sets some options on the new app: Many of the Heroku Platform API actions have optional parameters. For example, when creating an app, you can either specify a custom name, or allow the API to choose a random haiku name for your app. Optional parameters in heroku-go are always provided to functions as a pointer to a struct, such as AppCreateOpts for the function AppCreate(). If you do not wish to set any optional parameters, simply provide a nil in place of the options struct, and the options will be omitted from the API request entirely. For any individual options that you don't want to set, simply leave them as nil, and they will be omitted from the API request. List Ranges & Sorting Results from the Heroku API are paginated. You can specify a field for sorting and adjust the maximum number of records returned by providing a ListRange to API calls that list objects: Note Field is required when setting any range options.

Package iris is a web framework which provides efficient and well-designed tools with robust set of features to create your awesome and high-performance web application powered by unlimited potentials and portability. Source code and other details for the project are available at GitHub: Looking for further support? Note: This package is under active development status. Each month a new version is releasing to adapt the latest web trends and technologies. Iris is a very pluggable ecosystem, router can be customized by adapting a 'RouterBuilderPolicy && RouterReversionPolicy'. With the power of Iris' router adaptors, developers are able to use any third-party router's path features without any implications to the rest of their API. A Developer is able to select between two out-of-the-box powerful routers: Httprouter, it's a custom version of https://github.comjulienschmidt/httprouter, which is edited to support iris' subdomains, reverse routing, custom http errors and a lot features, it should be a bit faster than the original too because of iris' Context. It uses `/mypath/:firstParameter/path/:secondParameter` and `/mypath/*wildcardParamName` . Gorilla Mux, it's the https://github.com/gorilla/mux which supports subdomains, custom http errors, reverse routing, pattern matching via regex and the rest of the iris' features. It uses `/mypath/{firstParameter:any-regex-valid-here}/path/{secondParameter}` and `/mypath/{wildcardParamName:.*}` Example code: Run All HTTP methods are supported, users can register handlers for same paths on different methods. The first parameter is the HTTP Method, second parameter is the request path of the route, third variadic parameter should contains one or more iris.Handler/HandlerFunc executed by the registered order when a user requests for that specific resouce path from the server. Example code: In order to make things easier for the user, Iris provides functions for all HTTP Methods. The first parameter is the request path of the route, second variadic parameter should contains one or more iris.HandlerFunc executed by the registered order when a user requests for that specific resouce path from the server. Example code: Path Parameters' syntax depends on the selected router. This is the only difference between the routers, the registered path form, the API remains the same for both. Example `gorillamux` code: Example `httprouter` code: A set of routes that are being groupped by path prefix can (optionally) share the same middleware handlers and template layout. A group can have a nested group too. `.Party` is being used to group routes, developers can declare an unlimited number of (nested) groups. Example code: With iris users are able to register their own handlers for http statuses like 404 not found, 500 internal server error and so on. Example code: Custom http errors can be also be registered to a specific group of routes. Example code: Static Files Example code: Middleware is just a concept of ordered chain of handlers. Middleware can be registered globally, per-party, per-subdomain and per-route. Example code: Let's convert the https://github.com/rs/cors net/http external middleware which returns a `next form` handler. Example code: Iris supports 5 template engines out-of-the-box, developers can still use any external golang template engine, as `context.ResponseWriter` is an `io.Writer`. All of these five template engines have common features with common API, like Layout, Template Funcs, Party-specific layout, partial rendering and more. Example code: View engine supports bundled(https://github.com/jteeuwen/go-bindata) template files too. go-bindata gives you two functions, asset and assetNames, these can be setted to each of the template engines using the `.Binary` func. Example code: A real example can be found here: https://github.com/kataras/iris/tree/v6/_examples/intermediate/view/embedding-templates-into-app. Enable auto-reloading of templates on each request. Useful while developers are in dev mode as they no neeed to restart their app on every template edit. Example code: Each one of these template engines has different options located here: https://github.com/kataras/iris/tree/v6/adaptors/view . But you should have a basic idea of the framework by now, we just scratched the surface. If you enjoy what you just saw and want to learn more, please follow the below links: * Examples: https://github.com/iris-contrib/examples * Adaptors: https://github.com/kataras/iris/tree/v6/adaptors * Middleware: https://github.com/kataras/iris/tree/v6/middleware and * https://github.com/iris-contrib/middleware Package iris is a web framework which provides efficient and well-designed tools with robust set of features to create your awesome and high-performance web application powered by unlimited potentials and portability For view engines, render engines, sessions, websockets, subdomains, automatic-TLS, context support with 50+ handy http functions, dynamic subdomains, router & routes, parties of subdomains & routes, access control, typescript compiler, basicauth,internalization, logging, and much more, please visit https://godoc.org/gopkg.in/kataras/iris.v6

Package tcell provides a lower-level, portable API for building programs that interact with terminals or consoles. It works with both common (and many uncommon!) terminals or terminal emulators, and Windows console implementations. It provides support for up to 256 colors, text attributes, and box drawing elements. A database of terminals built from a real terminfo database is provided, along with code to generate new database entries. Tcell offers very rich support for mice, dependent upon the terminal of course. (Windows, XTerm, and iTerm 2 are known to work very well.) If the environment is not Unicode by default, such as an ISO8859 based locale or GB18030, Tcell can convert input and output, so that your terminal can operate in whatever locale is most convenient, while the application program can just assume "everything is UTF-8". Reasonable defaults are used for updating characters to something suitable for display. Unicode box drawing characters will be converted to use the alternate character set of your terminal, if native conversions are not available. If no ACS is available, then some ASCII fallbacks will be used. Note that support for non-UTF-8 locales (other than C) must be enabled by the application using RegisterEncoding() -- we don't have them all enabled by default to avoid bloating the application unneccessarily. (These days UTF-8 is good enough for almost everyone, and nobody should be using legacy locales anymore.) Also, actual glyphs for various code point will only be displayed if your terminal or emulator (or the font the emulator is using) supports them. A rich set of keycodes is supported, with support for up to 65 function keys, and various other special keys.

Package gofpdf implements a PDF document generator with high level support for text, drawing and images. - UTF-8 support - Choice of measurement unit, page format and margins - Page header and footer management - Automatic page breaks, line breaks, and text justification - Inclusion of JPEG, PNG, GIF, TIFF and basic path-only SVG images - Colors, gradients and alpha channel transparency - Outline bookmarks - Internal and external links - TrueType, Type1 and encoding support - Page compression - Lines, Bézier curves, arcs, and ellipses - Rotation, scaling, skewing, translation, and mirroring - Clipping - Document protection - Layers - Templates - Barcodes - Charting facility - Import PDFs as templates gofpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. gofpdf supports UTF-8 TrueType fonts and “right-to-left” languages. Note that Chinese, Japanese, and Korean characters may not be included in many general purpose fonts. For these languages, a specialized font (for example, NotoSansSC for simplified Chinese) can be used. Also, support is provided to automatically translate UTF-8 runes to code page encodings for languages that have fewer than 256 glyphs. This repository will not be maintained, at least for some unknown duration. But it is hoped that gofpdf has a bright future in the open source world. Due to Go’s promise of compatibility, gofpdf should continue to function without modification for a longer time than would be the case with many other languages. Forks should be based on the last viable commit. Tools such as active-forks can be used to select a fork that looks promising for your needs. If a particular fork looks like it has taken the lead in attracting followers, this README will be updated to point people in that direction. The efforts of all contributors to this project have been deeply appreciated. Best wishes to all of you. If you currently use the $GOPATH scheme, install the package with the following command. To test the installation, run The following Go code generates a simple PDF file. See the functions in the fpdf_test.go file (shown as examples in this documentation) for more advanced PDF examples. If an error occurs in an Fpdf method, an internal error field is set. After this occurs, Fpdf method calls typically return without performing any operations and the error state is retained. This error management scheme facilitates PDF generation since individual method calls do not need to be examined for failure; it is generally sufficient to wait until after Output() is called. For the same reason, if an error occurs in the calling application during PDF generation, it may be desirable for the application to transfer the error to the Fpdf instance by calling the SetError() method or the SetErrorf() method. At any time during the life cycle of the Fpdf instance, the error state can be determined with a call to Ok() or Err(). The error itself can be retrieved with a call to Error(). This package is a relatively straightforward translation from the original FPDF library written in PHP (despite the caveat in the introduction to Effective Go). The API names have been retained even though the Go idiom would suggest otherwise (for example, pdf.GetX() is used rather than simply pdf.X()). The similarity of the two libraries makes the original FPDF website a good source of information. It includes a forum and FAQ. However, some internal changes have been made. Page content is built up using buffers (of type bytes.Buffer) rather than repeated string concatenation. Errors are handled as explained above rather than panicking. Output is generated through an interface of type io.Writer or io.WriteCloser. A number of the original PHP methods behave differently based on the type of the arguments that are passed to them; in these cases additional methods have been exported to provide similar functionality. Font definition files are produced in JSON rather than PHP. A side effect of running go test ./... is the production of a number of example PDFs. These can be found in the gofpdf/pdf directory after the tests complete. Please note that these examples run in the context of a test. In order run an example as a standalone application, you’ll need to examine fpdf_test.go for some helper routines, for example exampleFilename() and summary(). Example PDFs can be compared with reference copies in order to verify that they have been generated as expected. This comparison will be performed if a PDF with the same name as the example PDF is placed in the gofpdf/pdf/reference directory and if the third argument to ComparePDFFiles() in internal/example/example.go is true. (By default it is false.) The routine that summarizes an example will look for this file and, if found, will call ComparePDFFiles() to check the example PDF for equality with its reference PDF. If differences exist between the two files they will be printed to standard output and the test will fail. If the reference file is missing, the comparison is considered to succeed. In order to successfully compare two PDFs, the placement of internal resources must be consistent and the internal creation timestamps must be the same. To do this, the methods SetCatalogSort() and SetCreationDate() need to be called for both files. This is done automatically for all examples. Nothing special is required to use the standard PDF fonts (courier, helvetica, times, zapfdingbats) in your documents other than calling SetFont(). You should use AddUTF8Font() or AddUTF8FontFromBytes() to add a TrueType UTF-8 encoded font. Use RTL() and LTR() methods switch between “right-to-left” and “left-to-right” mode. In order to use a different non-UTF-8 TrueType or Type1 font, you will need to generate a font definition file and, if the font will be embedded into PDFs, a compressed version of the font file. This is done by calling the MakeFont function or using the included makefont command line utility. To create the utility, cd into the makefont subdirectory and run “go build”. This will produce a standalone executable named makefont. Select the appropriate encoding file from the font subdirectory and run the command as in the following example. In your PDF generation code, call AddFont() to load the font and, as with the standard fonts, SetFont() to begin using it. Most examples, including the package example, demonstrate this method. Good sources of free, open-source fonts include Google Fonts and DejaVu Fonts. The draw2d package is a two dimensional vector graphics library that can generate output in different forms. It uses gofpdf for its document production mode. gofpdf is a global community effort and you are invited to make it even better. If you have implemented a new feature or corrected a problem, please consider contributing your change to the project. A contribution that does not directly pertain to the core functionality of gofpdf should be placed in its own directory directly beneath the contrib directory. Here are guidelines for making submissions. Your change should - be compatible with the MIT License - be properly documented - be formatted with go fmt - include an example in fpdf_test.go if appropriate - conform to the standards of golint and go vet, that is, golint . and go vet . should not generate any warnings - not diminish test coverage Pull requests are the preferred means of accepting your changes. gofpdf is released under the MIT License. It is copyrighted by Kurt Jung and the contributors acknowledged below. This package’s code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Bruno Michel has provided valuable assistance with the code. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF transparency script by Martin Hall-May. Support for gradients and clipping is adapted from FPDF scripts by Andreas Würmser. Support for outline bookmarks is adapted from Olivier Plathey by Manuel Cornes. Layer support is adapted from Olivier Plathey. Support for transformations is adapted from the FPDF transformation script by Moritz Wagner and Andreas Würmser. PDF protection is adapted from the work of Klemen Vodopivec for the FPDF product. Lawrence Kesteloot provided code to allow an image’s extent to be determined prior to placement. Support for vertical alignment within a cell was provided by Stefan Schroeder. Ivan Daniluk generalized the font and image loading code to use the Reader interface while maintaining backward compatibility. Anthony Starks provided code for the Polygon function. Robert Lillack provided the Beziergon function and corrected some naming issues with the internal curve function. Claudio Felber provided implementations for dashed line drawing and generalized font loading. Stani Michiels provided support for multi-segment path drawing with smooth line joins, line join styles, enhanced fill modes, and has helped greatly with package presentation and tests. Templating is adapted by Marcus Downing from the FPDF_Tpl library created by Jan Slabon and Setasign. Jelmer Snoeck contributed packages that generate a variety of barcodes and help with registering images on the web. Jelmer Snoek and Guillermo Pascual augmented the basic HTML functionality with aligned text. Kent Quirk implemented backwards-compatible support for reading DPI from images that support it, and for setting DPI manually and then having it properly taken into account when calculating image size. Paulo Coutinho provided support for static embedded fonts. Dan Meyers added support for embedded JavaScript. David Fish added a generic alias-replacement function to enable, among other things, table of contents functionality. Andy Bakun identified and corrected a problem in which the internal catalogs were not sorted stably. Paul Montag added encoding and decoding functionality for templates, including images that are embedded in templates; this allows templates to be stored independently of gofpdf. Paul also added support for page boxes used in printing PDF documents. Wojciech Matusiak added supported for word spacing. Artem Korotkiy added support of UTF-8 fonts. Dave Barnes added support for imported objects and templates. Brigham Thompson added support for rounded rectangles. Joe Westcott added underline functionality and optimized image storage. Benoit KUGLER contributed support for rectangles with corners of unequal radius, modification times, and for file attachments and annotations. - Remove all legacy code page font support; use UTF-8 exclusively - Improve test coverage as reported by the coverage tool. Example demonstrates the generation of a simple PDF document. Note that since only core fonts are used (in this case Arial, a synonym for Helvetica), an empty string can be specified for the font directory in the call to New(). Note also that the example.Filename() and example.Summary() functions belong to a separate, internal package and are not part of the gofpdf library. If an error occurs at some point during the construction of the document, subsequent method calls exit immediately and the error is finally retrieved with the output call where it can be handled by the application.

Package gofpdf implements a PDF document generator with high level support for text, drawing and images. - UTF-8 support - Choice of measurement unit, page format and margins - Page header and footer management - Automatic page breaks, line breaks, and text justification - Inclusion of JPEG, PNG, GIF, TIFF and basic path-only SVG images - Colors, gradients and alpha channel transparency - Outline bookmarks - Internal and external links - TrueType, Type1 and encoding support - Page compression - Lines, Bézier curves, arcs, and ellipses - Rotation, scaling, skewing, translation, and mirroring - Clipping - Document protection - Layers - Templates - Barcodes - Charting facility - Import PDFs as templates gofpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. gofpdf supports UTF-8 TrueType fonts and “right-to-left” languages. Note that Chinese, Japanese, and Korean characters may not be included in many general purpose fonts. For these languages, a specialized font (for example, NotoSansSC for simplified Chinese) can be used. Also, support is provided to automatically translate UTF-8 runes to code page encodings for languages that have fewer than 256 glyphs. This repository will not be maintained, at least for some unknown duration. But it is hoped that gofpdf has a bright future in the open source world. Due to Go’s promise of compatibility, gofpdf should continue to function without modification for a longer time than would be the case with many other languages. Forks should be based on the last viable commit. Tools such as active-forks can be used to select a fork that looks promising for your needs. If a particular fork looks like it has taken the lead in attracting followers, this README will be updated to point people in that direction. The efforts of all contributors to this project have been deeply appreciated. Best wishes to all of you. To install the package on your system, run Later, to receive updates, run The following Go code generates a simple PDF file. See the functions in the fpdf_test.go file (shown as examples in this documentation) for more advanced PDF examples. If an error occurs in an Fpdf method, an internal error field is set. After this occurs, Fpdf method calls typically return without performing any operations and the error state is retained. This error management scheme facilitates PDF generation since individual method calls do not need to be examined for failure; it is generally sufficient to wait until after Output() is called. For the same reason, if an error occurs in the calling application during PDF generation, it may be desirable for the application to transfer the error to the Fpdf instance by calling the SetError() method or the SetErrorf() method. At any time during the life cycle of the Fpdf instance, the error state can be determined with a call to Ok() or Err(). The error itself can be retrieved with a call to Error(). This package is a relatively straightforward translation from the original FPDF library written in PHP (despite the caveat in the introduction to Effective Go). The API names have been retained even though the Go idiom would suggest otherwise (for example, pdf.GetX() is used rather than simply pdf.X()). The similarity of the two libraries makes the original FPDF website a good source of information. It includes a forum and FAQ. However, some internal changes have been made. Page content is built up using buffers (of type bytes.Buffer) rather than repeated string concatenation. Errors are handled as explained above rather than panicking. Output is generated through an interface of type io.Writer or io.WriteCloser. A number of the original PHP methods behave differently based on the type of the arguments that are passed to them; in these cases additional methods have been exported to provide similar functionality. Font definition files are produced in JSON rather than PHP. A side effect of running go test ./... is the production of a number of example PDFs. These can be found in the gofpdf/pdf directory after the tests complete. Please note that these examples run in the context of a test. In order run an example as a standalone application, you’ll need to examine fpdf_test.go for some helper routines, for example exampleFilename() and summary(). Example PDFs can be compared with reference copies in order to verify that they have been generated as expected. This comparison will be performed if a PDF with the same name as the example PDF is placed in the gofpdf/pdf/reference directory and if the third argument to ComparePDFFiles() in internal/example/example.go is true. (By default it is false.) The routine that summarizes an example will look for this file and, if found, will call ComparePDFFiles() to check the example PDF for equality with its reference PDF. If differences exist between the two files they will be printed to standard output and the test will fail. If the reference file is missing, the comparison is considered to succeed. In order to successfully compare two PDFs, the placement of internal resources must be consistent and the internal creation timestamps must be the same. To do this, the methods SetCatalogSort() and SetCreationDate() need to be called for both files. This is done automatically for all examples. Nothing special is required to use the standard PDF fonts (courier, helvetica, times, zapfdingbats) in your documents other than calling SetFont(). You should use AddUTF8Font() or AddUTF8FontFromBytes() to add a TrueType UTF-8 encoded font. Use RTL() and LTR() methods switch between “right-to-left” and “left-to-right” mode. In order to use a different non-UTF-8 TrueType or Type1 font, you will need to generate a font definition file and, if the font will be embedded into PDFs, a compressed version of the font file. This is done by calling the MakeFont function or using the included makefont command line utility. To create the utility, cd into the makefont subdirectory and run “go build”. This will produce a standalone executable named makefont. Select the appropriate encoding file from the font subdirectory and run the command as in the following example. In your PDF generation code, call AddFont() to load the font and, as with the standard fonts, SetFont() to begin using it. Most examples, including the package example, demonstrate this method. Good sources of free, open-source fonts include Google Fonts and DejaVu Fonts. The draw2d package is a two dimensional vector graphics library that can generate output in different forms. It uses gofpdf for its document production mode. gofpdf is a global community effort and you are invited to make it even better. If you have implemented a new feature or corrected a problem, please consider contributing your change to the project. A contribution that does not directly pertain to the core functionality of gofpdf should be placed in its own directory directly beneath the contrib directory. Here are guidelines for making submissions. Your change should - be compatible with the MIT License - be properly documented - be formatted with go fmt - include an example in fpdf_test.go if appropriate - conform to the standards of golint and go vet, that is, golint . and go vet . should not generate any warnings - not diminish test coverage Pull requests are the preferred means of accepting your changes. gofpdf is released under the MIT License. It is copyrighted by Kurt Jung and the contributors acknowledged below. This package’s code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Bruno Michel has provided valuable assistance with the code. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF transparency script by Martin Hall-May. Support for gradients and clipping is adapted from FPDF scripts by Andreas Würmser. Support for outline bookmarks is adapted from Olivier Plathey by Manuel Cornes. Layer support is adapted from Olivier Plathey. Support for transformations is adapted from the FPDF transformation script by Moritz Wagner and Andreas Würmser. PDF protection is adapted from the work of Klemen Vodopivec for the FPDF product. Lawrence Kesteloot provided code to allow an image’s extent to be determined prior to placement. Support for vertical alignment within a cell was provided by Stefan Schroeder. Ivan Daniluk generalized the font and image loading code to use the Reader interface while maintaining backward compatibility. Anthony Starks provided code for the Polygon function. Robert Lillack provided the Beziergon function and corrected some naming issues with the internal curve function. Claudio Felber provided implementations for dashed line drawing and generalized font loading. Stani Michiels provided support for multi-segment path drawing with smooth line joins, line join styles, enhanced fill modes, and has helped greatly with package presentation and tests. Templating is adapted by Marcus Downing from the FPDF_Tpl library created by Jan Slabon and Setasign. Jelmer Snoeck contributed packages that generate a variety of barcodes and help with registering images on the web. Jelmer Snoek and Guillermo Pascual augmented the basic HTML functionality with aligned text. Kent Quirk implemented backwards-compatible support for reading DPI from images that support it, and for setting DPI manually and then having it properly taken into account when calculating image size. Paulo Coutinho provided support for static embedded fonts. Dan Meyers added support for embedded JavaScript. David Fish added a generic alias-replacement function to enable, among other things, table of contents functionality. Andy Bakun identified and corrected a problem in which the internal catalogs were not sorted stably. Paul Montag added encoding and decoding functionality for templates, including images that are embedded in templates; this allows templates to be stored independently of gofpdf. Paul also added support for page boxes used in printing PDF documents. Wojciech Matusiak added supported for word spacing. Artem Korotkiy added support of UTF-8 fonts. Dave Barnes added support for imported objects and templates. Brigham Thompson added support for rounded rectangles. Joe Westcott added underline functionality and optimized image storage. Benoit KUGLER contributed support for rectangles with corners of unequal radius, modification times, and for file attachments and annotations. - Remove all legacy code page font support; use UTF-8 exclusively - Improve test coverage as reported by the coverage tool. Example demonstrates the generation of a simple PDF document. Note that since only core fonts are used (in this case Arial, a synonym for Helvetica), an empty string can be specified for the font directory in the call to New(). Note also that the example.Filename() and example.Summary() functions belong to a separate, internal package and are not part of the gofpdf library. If an error occurs at some point during the construction of the document, subsequent method calls exit immediately and the error is finally retrieved with the output call where it can be handled by the application.

Package tcell provides a lower-level, portable API for building programs that interact with terminals or consoles. It works with both common (and many uncommon!) terminals or terminal emulators, and Windows console implementations. It provides support for up to 256 colors, text attributes, and box drawing elements. A database of terminals built from a real terminfo database is provided, along with code to generate new database entries. Tcell offers very rich support for mice, dependent upon the terminal of course. (Windows, XTerm, and iTerm 2 are known to work very well.) If the environment is not Unicode by default, such as an ISO8859 based locale or GB18030, Tcell can convert input and output, so that your terminal can operate in whatever locale is most convenient, while the application program can just assume "everything is UTF-8". Reasonable defaults are used for updating characters to something suitable for display. Unicode box drawing characters will be converted to use the alternate character set of your terminal, if native conversions are not available. If no ACS is available, then some ASCII fallbacks will be used. Note that support for non-UTF-8 locales (other than C) must be enabled by the application using RegisterEncoding() -- we don't have them all enabled by default to avoid bloating the application unneccessarily. (These days UTF-8 is good enough for almost everyone, and nobody should be using legacy locales anymore.) Also, actual glyphs for various code point will only be displayed if your terminal or emulator (or the font the emulator is using) supports them. A rich set of keycodes is supported, with support for up to 65 function keys, and various other special keys.

Package tcell provides a lower-level, portable API for building programs that interact with terminals or consoles. It works with both common (and many uncommon!) terminals or terminal emulators, and Windows console implementations. It provides support for up to 256 colors, text attributes, and box drawing elements. A database of terminals built from a real terminfo database is provided, along with code to generate new database entries. Tcell offers very rich support for mice, dependent upon the terminal of course. (Windows, XTerm, and iTerm 2 are known to work very well.) If the environment is not Unicode by default, such as an ISO8859 based locale or GB18030, Tcell can convert input and output, so that your terminal can operate in whatever locale is most convenient, while the application program can just assume "everything is UTF-8". Reasonable defaults are used for updating characters to something suitable for display. Unicode box drawing characters will be converted to use the alternate character set of your terminal, if native conversions are not available. If no ACS is available, then some ASCII fallbacks will be used. Note that support for non-UTF-8 locales (other than C) must be enabled by the application using RegisterEncoding() -- we don't have them all enabled by default to avoid bloating the application unnecessarily. (These days UTF-8 is good enough for almost everyone, and nobody should be using legacy locales anymore.) Also, actual glyphs for various code point will only be displayed if your terminal or emulator (or the font the emulator is using) supports them. A rich set of key codes is supported, with support for up to 65 function keys, and various other special keys.

Package tcell provides a lower-level, portable API for building programs that interact with terminals or consoles. It works with both common (and many uncommon!) terminals or terminal emulators, and Windows console implementations. It provides support for up to 256 colors, text attributes, and box drawing elements. A database of terminals built from a real terminfo database is provided, along with code to generate new database entries. Tcell offers very rich support for mice, dependent upon the terminal of course. (Windows, XTerm, and iTerm 2 are known to work very well.) If the environment is not Unicode by default, such as an ISO8859 based locale or GB18030, Tcell can convert input and output, so that your terminal can operate in whatever locale is most convenient, while the application program can just assume "everything is UTF-8". Reasonable defaults are used for updating characters to something suitable for display. Unicode box drawing characters will be converted to use the alternate character set of your terminal, if native conversions are not available. If no ACS is available, then some ASCII fallbacks will be used. Note that support for non-UTF-8 locales (other than C) must be enabled by the application using RegisterEncoding() -- we don't have them all enabled by default to avoid bloating the application unneccessarily. (These days UTF-8 is good enough for almost everyone, and nobody should be using legacy locales anymore.) Also, actual glyphs for various code point will only be displayed if your terminal or emulator (or the font the emulator is using) supports them. A rich set of keycodes is supported, with support for up to 65 function keys, and various other special keys.

Package goji provides an out-of-box web server with reasonable defaults. Example: This package exists purely as a convenience to programmers who want to get started as quickly as possible. It draws almost all of its code from goji's subpackages, the most interesting of which is goji/web, and where most of the documentation for the web framework lives. A side effect of this package's ease-of-use is the fact that it is opinionated. If you don't like (or have outgrown) its opinions, it should be straightforward to use the APIs of goji's subpackages to reimplement things to your liking. Both methods of using this library are equally well supported. Goji requires Go 1.2 or newer.

Package goji provides an out-of-box web server with reasonable defaults. Example: This package exists purely as a convenience to programmers who want to get started as quickly as possible. It draws almost all of its code from goji's subpackages, the most interesting of which is goji/web, and where most of the documentation for the web framework lives. A side effect of this package's ease-of-use is the fact that it is opinionated. If you don't like (or have outgrown) its opinions, it should be straightforward to use the APIs of goji's subpackages to reimplement things to your liking. Both methods of using this library are equally well supported. Goji requires Go 1.2 or newer.

Package goji provides an out-of-box web server with reasonable defaults. Example: This package exists purely as a convenience to programmers who want to get started as quickly as possible. It draws almost all of its code from goji's subpackages, the most interesting of which is goji/web, and where most of the documentation for the web framework lives. A side effect of this package's ease-of-use is the fact that it is opinionated. If you don't like (or have outgrown) its opinions, it should be straightforward to use the APIs of goji's subpackages to reimplement things to your liking. Both methods of using this library are equally well supported. Goji requires Go 1.2 or newer.

SQL Schema migration tool for Go. Key features: To install the library and command line program, use the following: The main command is called sql-migrate. Each command requires a configuration file (which defaults to dbconfig.yml, but can be specified with the -config flag). This config file should specify one or more environments: The `table` setting is optional and will default to `gorp_migrations`. The environment that will be used can be specified with the -env flag (defaults to development). Use the --help flag in combination with any of the commands to get an overview of its usage: The up command applies all available migrations. By contrast, down will only apply one migration by default. This behavior can be changed for both by using the -limit parameter. The redo command will unapply the last migration and reapply it. This is useful during development, when you're writing migrations. Use the status command to see the state of the applied migrations: If you are using MySQL, you must append ?parseTime=true to the datasource configuration. For example: See https://github.com/go-sql-driver/mysql#parsetime for more information. Import sql-migrate into your application: Set up a source of migrations, this can be from memory, from a set of files or from bindata (more on that later): Then use the Exec function to upgrade your database: Note that n can be greater than 0 even if there is an error: any migration that succeeded will remain applied even if a later one fails. The full set of capabilities can be found in the API docs below. Migrations are defined in SQL files, which contain a set of SQL statements. Special comments are used to distinguish up and down migrations. You can put multiple statements in each block, as long as you end them with a semicolon (;). If you have complex statements which contain semicolons, use StatementBegin and StatementEnd to indicate boundaries: The order in which migrations are applied is defined through the filename: sql-migrate will sort migrations based on their name. It's recommended to use an increasing version number or a timestamp as the first part of the filename. Normally each migration is run within a transaction in order to guarantee that it is fully atomic. However some SQL commands (for example creating an index concurrently in PostgreSQL) cannot be executed inside a transaction. In order to execute such a command in a migration, the migration can be run using the notransaction option: If you like your Go applications self-contained (that is: a single binary): use packr (https://github.com/gobuffalo/packr) to embed the migration files. Just write your migration files as usual, as a set of SQL files in a folder. Use the PackrMigrationSource in your application to find the migrations: If you already have a box and would like to use a subdirectory: As an alternative, but slightly less maintained, you can use bindata (https://github.com/shuLhan/go-bindata) to embed the migration files. Just write your migration files as usual, as a set of SQL files in a folder. Then use bindata to generate a .go file with the migrations embedded: The resulting bindata.go file will contain your migrations. Remember to regenerate your bindata.go file whenever you add/modify a migration (go generate will help here, once it arrives). Use the AssetMigrationSource in your application to find the migrations: Both Asset and AssetDir are functions provided by bindata. Then proceed as usual. Adding a new migration source means implementing MigrationSource. The resulting slice of migrations will be executed in the given order, so it should usually be sorted by the Id field.

Package tcell provides a lower-level, portable API for building programs that interact with terminals or consoles. It works with both common (and many uncommon!) terminals or terminal emulators, and Windows console implementations. It provides support for up to 256 colors, text attributes, and box drawing elements. A database of terminals built from a real terminfo database is provided, along with code to generate new database entries. Tcell offers very rich support for mice, dependent upon the terminal of course. (Windows, XTerm, and iTerm 2 are known to work very well.) If the environment is not Unicode by default, such as an ISO8859 based locale or GB18030, Tcell can convert input and output, so that your terminal can operate in whatever locale is most convenient, while the application program can just assume "everything is UTF-8". Reasonable defaults are used for updating characters to something suitable for display. Unicode box drawing characters will be converted to use the alternate character set of your terminal, if native conversions are not available. If no ACS is available, then some ASCII fallbacks will be used. Note that support for non-UTF-8 locales (other than C) must be enabled by the application using RegisterEncoding() -- we don't have them all enabled by default to avoid bloating the application unneccessarily. (These days UTF-8 is good enough for almost everyone, and nobody should be using legacy locales anymore.) Also, actual glyphs for various code point will only be displayed if your terminal or emulator (or the font the emulator is using) supports them. A rich set of keycodes is supported, with support for up to 65 function keys, and various other special keys.

Package duit is a pure go, cross-platform, MIT-licensed, UI toolkit for developers. The examples/ directory has small code examples for working with duit and its UIs. Examples are the recommended starting point. Start with NewDUI to create a DUI: essentially a window and all the UI state. The user interface consists of a hierarchy of "UIs" like Box, Scroll, Button, Label, etc. They are called UIs, after the interface UI they all implement. The zero structs for UIs have sane default behaviour so you only have to fill in the fields you need. UIs are kept/wrapped in a Kid, to track their layout/draw state. Use NewKids() to build up the UIs for your application. You won't see much of the Kid-types/functions otherwise, unless you implement a new UI. You are in charge of the main event loop, receiving mouse/keyboard/window events from the dui.Inputs channel, and typically passing them on unchanged to dui.Input. All callbacks and functions on UIs are called from inside dui.Input. From there you can also safely change the the UIs, no locking required. After changing a UI you are responsible for calling MarkLayout or MarkDraw to tell duit the UI needs a new layout or draw. This may sound like more work, but this tradeoff keeps the API small and easy to use. If you need to change the UI from a goroutine outside of the main loop, e.g. for blocking calls, you can send a function that makes those modifications on the dui.Call channel, which will be run on the main channel through dui.Inputs. After handling an input, duit will layout or draw as necessary, no need to render explicitly. Embedding a UI into your own data structure is often an easy way to build up UI hiearchies. Scroll and Edit show a scrollbar. Use button 1 on the scrollbar to scroll up, button 3 to scroll down. If you click more near the top, you scroll less. More near the bottom, more. Button 2 scrolls to the absolute place, where you clicked. Button 4 and 5 are wheel up and wheel down, and also scroll less/more depending on position in the UI.

Package aw is a "plug-and-play" workflow development library/framework for Alfred 3 & 4 (https://www.alfredapp.com/). It requires Go 1.13 or later. It provides everything you need to create a polished and blazing-fast Alfred frontend for your project. As of AwGo 0.26, all applicable features of Alfred 4.1 are supported. The main features are: AwGo is an opinionated framework that expects to be used in a certain way in order to eliminate boilerplate. It *will* panic if not run in a valid, minimally Alfred-like environment. At a minimum the following environment variables should be set to meaningful values: NOTE: AwGo is currently in development. The API *will* change and should not be considered stable until v1.0. Until then, be sure to pin a version using go modules or similar. Be sure to also check out the _examples/ subdirectory, which contains some simple, but complete, workflows that demonstrate the features of AwGo and useful workflow idioms. Typically, you'd call your program's main entry point via Workflow.Run(). This way, the library will rescue any panic, log the stack trace and show an error message to the user in Alfred. In the Script box (Language = "/bin/bash"): To generate results for Alfred to show in a Script Filter, use the feedback API of Workflow: You can set workflow variables (via feedback) with Workflow.Var, Item.Var and Modifier.Var. See Workflow.SendFeedback for more documentation. Alfred requires a different JSON format if you wish to set workflow variables. Use the ArgVars (named for its equivalent element in Alfred) struct to generate output from Run Script actions. Be sure to set TextErrors to true to prevent Workflow from generating Alfred JSON if it catches a panic: See ArgVars for more information. New() creates a *Workflow using the default values and workflow settings read from environment variables set by Alfred. You can change defaults by passing one or more Options to New(). If you do not want to use Alfred's environment variables, or they aren't set (i.e. you're not running the code in Alfred), use NewFromEnv() with a custom Env implementation. A Workflow can be re-configured later using its Configure() method. See the documentation for Option for more information on configuring a Workflow. AwGo can check for and install new versions of your workflow. Subpackage update provides an implementation of the Updater interface and sources to load updates from GitHub or Gitea releases, or from the URL of an Alfred `metadata.json` file. See subpackage update and _examples/update. AwGo can filter Script Filter feedback using a Sublime Text-like fuzzy matching algorithm. Workflow.Filter() sorts feedback Items against the provided query, removing those that do not match. See _examples/fuzzy for a basic demonstration, and _examples/bookmarks for a demonstration of implementing fuzzy.Sortable on your own structs and customising the fuzzy sort settings. Fuzzy matching is done by package https://godoc.org/go.deanishe.net/fuzzy AwGo automatically configures the default log package to write to STDERR (Alfred's debugger) and a log file in the workflow's cache directory. The log file is necessary because background processes aren't connected to Alfred, so their output is only visible in the log. It is rotated when it exceeds 1 MiB in size. One previous log is kept. AwGo detects when Alfred's debugger is open (Workflow.Debug() returns true) and in this case prepends filename:linenumber: to log messages. The Config struct (which is included in Workflow as Workflow.Config) provides an interface to the workflow's settings from the Workflow Environment Variables panel (see https://www.alfredapp.com/help/workflows/advanced/variables/#environment). Alfred exports these settings as environment variables, and you can read them ad-hoc with the Config.Get*() methods, and save values back to Alfred/info.plist with Config.Set(). Using Config.To() and Config.From(), you can "bind" your own structs to the settings in Alfred: See the documentation for Config.To and Config.From for more information, and _examples/settings for a demo workflow based on the API. The Alfred struct provides methods for the rest of Alfred's AppleScript API. Amongst other things, you can use it to tell Alfred to open, to search for a query, to browse/action files & directories, or to run External Triggers. See documentation of the Alfred struct for more information. AwGo provides a basic, but useful, API for loading and saving data. In addition to reading/writing bytes and marshalling/unmarshalling to/from JSON, the API can auto-refresh expired cache data. See Cache and Session for the API documentation. Workflow has three caches tied to different directories: These all share (almost) the same API. The difference is in when the data go away. Data saved with Session are deleted after the user closes Alfred or starts using a different workflow. The Cache directory is in a system cache directory, so may be deleted by the system or "system maintenance" tools. The Data directory lives with Alfred's application data and would not normally be deleted. Subpackage util provides several functions for running script files and snippets of AppleScript/JavaScript code. See util for documentation and examples. AwGo offers a simple API to start/stop background processes via Workflow's RunInBackground(), IsRunning() and Kill() methods. This is useful for running checks for updates and other jobs that hit the network or take a significant amount of time to complete, allowing you to keep your Script Filters extremely responsive. See _examples/update and _examples/workflows for demonstrations of this API.

Package aw is a "plug-and-play" workflow development library/framework for Alfred 3 & 4 (https://www.alfredapp.com/). It requires Go 1.13 or later. It provides everything you need to create a polished and blazing-fast Alfred frontend for your project. As of AwGo 0.26, all applicable features of Alfred 4.1 are supported. The main features are: AwGo is an opinionated framework that expects to be used in a certain way in order to eliminate boilerplate. It *will* panic if not run in a valid, minimally Alfred-like environment. At a minimum the following environment variables should be set to meaningful values: NOTE: AwGo is currently in development. The API *will* change and should not be considered stable until v1.0. Until then, be sure to pin a version using go modules or similar. Be sure to also check out the _examples/ subdirectory, which contains some simple, but complete, workflows that demonstrate the features of AwGo and useful workflow idioms. Typically, you'd call your program's main entry point via Workflow.Run(). This way, the library will rescue any panic, log the stack trace and show an error message to the user in Alfred. In the Script box (Language = "/bin/bash"): To generate results for Alfred to show in a Script Filter, use the feedback API of Workflow: You can set workflow variables (via feedback) with Workflow.Var, Item.Var and Modifier.Var. See Workflow.SendFeedback for more documentation. Alfred requires a different JSON format if you wish to set workflow variables. Use the ArgVars (named for its equivalent element in Alfred) struct to generate output from Run Script actions. Be sure to set TextErrors to true to prevent Workflow from generating Alfred JSON if it catches a panic: See ArgVars for more information. New() creates a *Workflow using the default values and workflow settings read from environment variables set by Alfred. You can change defaults by passing one or more Options to New(). If you do not want to use Alfred's environment variables, or they aren't set (i.e. you're not running the code in Alfred), use NewFromEnv() with a custom Env implementation. A Workflow can be re-configured later using its Configure() method. See the documentation for Option for more information on configuring a Workflow. AwGo can check for and install new versions of your workflow. Subpackage update provides an implementation of the Updater interface and sources to load updates from GitHub or Gitea releases, or from the URL of an Alfred `metadata.json` file. See subpackage update and _examples/update. AwGo can filter Script Filter feedback using a Sublime Text-like fuzzy matching algorithm. Workflow.Filter() sorts feedback Items against the provided query, removing those that do not match. See _examples/fuzzy for a basic demonstration, and _examples/bookmarks for a demonstration of implementing fuzzy.Sortable on your own structs and customising the fuzzy sort settings. Fuzzy matching is done by package https://godoc.org/go.deanishe.net/fuzzy AwGo automatically configures the default log package to write to STDERR (Alfred's debugger) and a log file in the workflow's cache directory. The log file is necessary because background processes aren't connected to Alfred, so their output is only visible in the log. It is rotated when it exceeds 1 MiB in size. One previous log is kept. AwGo detects when Alfred's debugger is open (Workflow.Debug() returns true) and in this case prepends filename:linenumber: to log messages. The Config struct (which is included in Workflow as Workflow.Config) provides an interface to the workflow's settings from the Workflow Environment Variables panel (see https://www.alfredapp.com/help/workflows/advanced/variables/#environment). Alfred exports these settings as environment variables, and you can read them ad-hoc with the Config.Get*() methods, and save values back to Alfred/info.plist with Config.Set(). Using Config.To() and Config.From(), you can "bind" your own structs to the settings in Alfred: See the documentation for Config.To and Config.From for more information, and _examples/settings for a demo workflow based on the API. The Alfred struct provides methods for the rest of Alfred's AppleScript API. Amongst other things, you can use it to tell Alfred to open, to search for a query, to browse/action files & directories, or to run External Triggers. See documentation of the Alfred struct for more information. AwGo provides a basic, but useful, API for loading and saving data. In addition to reading/writing bytes and marshalling/unmarshalling to/from JSON, the API can auto-refresh expired cache data. See Cache and Session for the API documentation. Workflow has three caches tied to different directories: These all share (almost) the same API. The difference is in when the data go away. Data saved with Session are deleted after the user closes Alfred or starts using a different workflow. The Cache directory is in a system cache directory, so may be deleted by the system or "system maintenance" tools. The Data directory lives with Alfred's application data and would not normally be deleted. Subpackage util provides several functions for running script files and snippets of AppleScript/JavaScript code. See util for documentation and examples. AwGo offers a simple API to start/stop background processes via Workflow's RunInBackground(), IsRunning() and Kill() methods. This is useful for running checks for updates and other jobs that hit the network or take a significant amount of time to complete, allowing you to keep your Script Filters extremely responsive. See _examples/update and _examples/workflows for demonstrations of this API.

Package decimal provides a high-performance, arbitrary precision, floating-point decimal library. This package provides floating-point decimal numbers, useful for financial programming or calculations where a larger, more accurate representation of a number is required. In addition to basic arithmetic operations (addition, subtraction, multiplication, and division) this package offers various mathematical functions, including the exponential function, various logarithms, and the ability to compute continued fractions. While lean, this package is full of features. It implements interfaces like “fmt.Formatter” and intuitively utilizes verbs and flags as described in the “fmt” package. (Also included: “fmt.Scanner”, “fmt.Stringer”, “encoding.TextUnmarshaler”, and “encoding.TextMarshaler”.) It allows users to specific explicit contexts for arithmetic operations, but doesn't require it. It provides access to NaN payloads and is more lenient when parsing a decimal from a string than the GDA specification requires. API interfaces have been changed slightly to work more seamlessly with existing Go programs. For example, many “Quantize” implementations require a decimal as both the receiver and argument which isn't very user friendly. Instead, this library accepts a simple “int” which can be derived from an existing decimal if required. It contains two modes of operation designed to make transitioning to various GDA "quirks" (like always rounding lossless operations) easier. There are three primary goals of this library: By adhering to the General Decimal Arithmetic specification, this package has a well-defined structure for its arithmetic operations. Decimal libraries are inherently slow; this library works diligently to minimize memory allocations and utilize efficient algorithms. Performance regularly benchmarks as fast or faster than many other popular decimal libraries. Libraries should be intuitive and work out of the box without having to configure too many settings; however, precise settings should still be available. The following type is supported: The zero value for a Big corresponds with 0, meaning all the following are valid: Method naming is the same as math/big's, meaning: In general, its conventions mirror math/big's. It is suggested to read the math/big package comments to gain an understanding of this package's conventions. Arguments to Binary and Unary methods are allowed to alias, so the following is valid: Unless otherwise specified, the only argument that will be modified is the result (“z”). This means the following is valid and race-free: But this is not:

Package gofpdf implements a PDF document generator with high level support for text, drawing and images. - UTF-8 support - Choice of measurement unit, page format and margins - Page header and footer management - Automatic page breaks, line breaks, and text justification - Inclusion of JPEG, PNG, GIF, TIFF and basic path-only SVG images - Colors, gradients and alpha channel transparency - Outline bookmarks - Internal and external links - TrueType, Type1 and encoding support - Page compression - Lines, Bézier curves, arcs, and ellipses - Rotation, scaling, skewing, translation, and mirroring - Clipping - Document protection - Layers - Templates - Barcodes - Charting facility - Import PDFs as templates gofpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. gofpdf supports UTF-8 TrueType fonts and “right-to-left” languages. Note that Chinese, Japanese, and Korean characters may not be included in many general purpose fonts. For these languages, a specialized font (for example, NotoSansSC for simplified Chinese) can be used. Also, support is provided to automatically translate UTF-8 runes to code page encodings for languages that have fewer than 256 glyphs. This repository will not be maintained, at least for some unknown duration. But it is hoped that gofpdf has a bright future in the open source world. Due to Go’s promise of compatibility, gofpdf should continue to function without modification for a longer time than would be the case with many other languages. Forks should be based on the last viable commit. Tools such as active-forks can be used to select a fork that looks promising for your needs. If a particular fork looks like it has taken the lead in attracting followers, this README will be updated to point people in that direction. The efforts of all contributors to this project have been deeply appreciated. Best wishes to all of you. To install the package on your system, run Later, to receive updates, run The following Go code generates a simple PDF file. See the functions in the fpdf_test.go file (shown as examples in this documentation) for more advanced PDF examples. If an error occurs in an Fpdf method, an internal error field is set. After this occurs, Fpdf method calls typically return without performing any operations and the error state is retained. This error management scheme facilitates PDF generation since individual method calls do not need to be examined for failure; it is generally sufficient to wait until after Output() is called. For the same reason, if an error occurs in the calling application during PDF generation, it may be desirable for the application to transfer the error to the Fpdf instance by calling the SetError() method or the SetErrorf() method. At any time during the life cycle of the Fpdf instance, the error state can be determined with a call to Ok() or Err(). The error itself can be retrieved with a call to Error(). This package is a relatively straightforward translation from the original FPDF library written in PHP (despite the caveat in the introduction to Effective Go). The API names have been retained even though the Go idiom would suggest otherwise (for example, pdf.GetX() is used rather than simply pdf.X()). The similarity of the two libraries makes the original FPDF website a good source of information. It includes a forum and FAQ. However, some internal changes have been made. Page content is built up using buffers (of type bytes.Buffer) rather than repeated string concatenation. Errors are handled as explained above rather than panicking. Output is generated through an interface of type io.Writer or io.WriteCloser. A number of the original PHP methods behave differently based on the type of the arguments that are passed to them; in these cases additional methods have been exported to provide similar functionality. Font definition files are produced in JSON rather than PHP. A side effect of running go test ./... is the production of a number of example PDFs. These can be found in the gofpdf/pdf directory after the tests complete. Please note that these examples run in the context of a test. In order run an example as a standalone application, you’ll need to examine fpdf_test.go for some helper routines, for example exampleFilename() and summary(). Example PDFs can be compared with reference copies in order to verify that they have been generated as expected. This comparison will be performed if a PDF with the same name as the example PDF is placed in the gofpdf/pdf/reference directory and if the third argument to ComparePDFFiles() in internal/example/example.go is true. (By default it is false.) The routine that summarizes an example will look for this file and, if found, will call ComparePDFFiles() to check the example PDF for equality with its reference PDF. If differences exist between the two files they will be printed to standard output and the test will fail. If the reference file is missing, the comparison is considered to succeed. In order to successfully compare two PDFs, the placement of internal resources must be consistent and the internal creation timestamps must be the same. To do this, the methods SetCatalogSort() and SetCreationDate() need to be called for both files. This is done automatically for all examples. Nothing special is required to use the standard PDF fonts (courier, helvetica, times, zapfdingbats) in your documents other than calling SetFont(). You should use AddUTF8Font() or AddUTF8FontFromBytes() to add a TrueType UTF-8 encoded font. Use RTL() and LTR() methods switch between “right-to-left” and “left-to-right” mode. In order to use a different non-UTF-8 TrueType or Type1 font, you will need to generate a font definition file and, if the font will be embedded into PDFs, a compressed version of the font file. This is done by calling the MakeFont function or using the included makefont command line utility. To create the utility, cd into the makefont subdirectory and run “go build”. This will produce a standalone executable named makefont. Select the appropriate encoding file from the font subdirectory and run the command as in the following example. In your PDF generation code, call AddFont() to load the font and, as with the standard fonts, SetFont() to begin using it. Most examples, including the package example, demonstrate this method. Good sources of free, open-source fonts include Google Fonts and DejaVu Fonts. The draw2d package is a two dimensional vector graphics library that can generate output in different forms. It uses gofpdf for its document production mode. gofpdf is a global community effort and you are invited to make it even better. If you have implemented a new feature or corrected a problem, please consider contributing your change to the project. A contribution that does not directly pertain to the core functionality of gofpdf should be placed in its own directory directly beneath the contrib directory. Here are guidelines for making submissions. Your change should - be compatible with the MIT License - be properly documented - be formatted with go fmt - include an example in fpdf_test.go if appropriate - conform to the standards of golint and go vet, that is, golint . and go vet . should not generate any warnings - not diminish test coverage Pull requests are the preferred means of accepting your changes. gofpdf is released under the MIT License. It is copyrighted by Kurt Jung and the contributors acknowledged below. This package’s code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Bruno Michel has provided valuable assistance with the code. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF transparency script by Martin Hall-May. Support for gradients and clipping is adapted from FPDF scripts by Andreas Würmser. Support for outline bookmarks is adapted from Olivier Plathey by Manuel Cornes. Layer support is adapted from Olivier Plathey. Support for transformations is adapted from the FPDF transformation script by Moritz Wagner and Andreas Würmser. PDF protection is adapted from the work of Klemen Vodopivec for the FPDF product. Lawrence Kesteloot provided code to allow an image’s extent to be determined prior to placement. Support for vertical alignment within a cell was provided by Stefan Schroeder. Ivan Daniluk generalized the font and image loading code to use the Reader interface while maintaining backward compatibility. Anthony Starks provided code for the Polygon function. Robert Lillack provided the Beziergon function and corrected some naming issues with the internal curve function. Claudio Felber provided implementations for dashed line drawing and generalized font loading. Stani Michiels provided support for multi-segment path drawing with smooth line joins, line join styles, enhanced fill modes, and has helped greatly with package presentation and tests. Templating is adapted by Marcus Downing from the FPDF_Tpl library created by Jan Slabon and Setasign. Jelmer Snoeck contributed packages that generate a variety of barcodes and help with registering images on the web. Jelmer Snoek and Guillermo Pascual augmented the basic HTML functionality with aligned text. Kent Quirk implemented backwards-compatible support for reading DPI from images that support it, and for setting DPI manually and then having it properly taken into account when calculating image size. Paulo Coutinho provided support for static embedded fonts. Dan Meyers added support for embedded JavaScript. David Fish added a generic alias-replacement function to enable, among other things, table of contents functionality. Andy Bakun identified and corrected a problem in which the internal catalogs were not sorted stably. Paul Montag added encoding and decoding functionality for templates, including images that are embedded in templates; this allows templates to be stored independently of gofpdf. Paul also added support for page boxes used in printing PDF documents. Wojciech Matusiak added supported for word spacing. Artem Korotkiy added support of UTF-8 fonts. Dave Barnes added support for imported objects and templates. Brigham Thompson added support for rounded rectangles. Joe Westcott added underline functionality and optimized image storage. Benoit KUGLER contributed support for rectangles with corners of unequal radius, modification times, and for file attachments and annotations. - Remove all legacy code page font support; use UTF-8 exclusively - Improve test coverage as reported by the coverage tool. Example demonstrates the generation of a simple PDF document. Note that since only core fonts are used (in this case Arial, a synonym for Helvetica), an empty string can be specified for the font directory in the call to New(). Note also that the example.Filename() and example.Summary() functions belong to a separate, internal package and are not part of the gofpdf library. If an error occurs at some point during the construction of the document, subsequent method calls exit immediately and the error is finally retrieved with the output call where it can be handled by the application.

Package gofpdf implements a PDF document generator with high level support for text, drawing and images. - UTF-8 support - Choice of measurement unit, page format and margins - Page header and footer management - Automatic page breaks, line breaks, and text justification - Inclusion of JPEG, PNG, GIF, TIFF and basic path-only SVG images - Colors, gradients and alpha channel transparency - Outline bookmarks - Internal and external links - TrueType, Type1 and encoding support - Page compression - Lines, Bézier curves, arcs, and ellipses - Rotation, scaling, skewing, translation, and mirroring - Clipping - Document protection - Layers - Templates - Barcodes - Charting facility - Import PDFs as templates gofpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. gofpdf supports UTF-8 TrueType fonts and “right-to-left” languages. Note that Chinese, Japanese, and Korean characters may not be included in many general purpose fonts. For these languages, a specialized font (for example, NotoSansSC for simplified Chinese) can be used. Also, support is provided to automatically translate UTF-8 runes to code page encodings for languages that have fewer than 256 glyphs. This repository will not be maintained, at least for some unknown duration. But it is hoped that gofpdf has a bright future in the open source world. Due to Go’s promise of compatibility, gofpdf should continue to function without modification for a longer time than would be the case with many other languages. Forks should be based on the last viable commit. Tools such as active-forks can be used to select a fork that looks promising for your needs. If a particular fork looks like it has taken the lead in attracting followers, this README will be updated to point people in that direction. The efforts of all contributors to this project have been deeply appreciated. Best wishes to all of you. To install the package on your system, run Later, to receive updates, run The following Go code generates a simple PDF file. See the functions in the fpdf_test.go file (shown as examples in this documentation) for more advanced PDF examples. If an error occurs in an Fpdf method, an internal error field is set. After this occurs, Fpdf method calls typically return without performing any operations and the error state is retained. This error management scheme facilitates PDF generation since individual method calls do not need to be examined for failure; it is generally sufficient to wait until after Output() is called. For the same reason, if an error occurs in the calling application during PDF generation, it may be desirable for the application to transfer the error to the Fpdf instance by calling the SetError() method or the SetErrorf() method. At any time during the life cycle of the Fpdf instance, the error state can be determined with a call to Ok() or Err(). The error itself can be retrieved with a call to Error(). This package is a relatively straightforward translation from the original FPDF library written in PHP (despite the caveat in the introduction to Effective Go). The API names have been retained even though the Go idiom would suggest otherwise (for example, pdf.GetX() is used rather than simply pdf.X()). The similarity of the two libraries makes the original FPDF website a good source of information. It includes a forum and FAQ. However, some internal changes have been made. Page content is built up using buffers (of type bytes.Buffer) rather than repeated string concatenation. Errors are handled as explained above rather than panicking. Output is generated through an interface of type io.Writer or io.WriteCloser. A number of the original PHP methods behave differently based on the type of the arguments that are passed to them; in these cases additional methods have been exported to provide similar functionality. Font definition files are produced in JSON rather than PHP. A side effect of running go test ./... is the production of a number of example PDFs. These can be found in the gofpdf/pdf directory after the tests complete. Please note that these examples run in the context of a test. In order run an example as a standalone application, you’ll need to examine fpdf_test.go for some helper routines, for example exampleFilename() and summary(). Example PDFs can be compared with reference copies in order to verify that they have been generated as expected. This comparison will be performed if a PDF with the same name as the example PDF is placed in the gofpdf/pdf/reference directory and if the third argument to ComparePDFFiles() in internal/example/example.go is true. (By default it is false.) The routine that summarizes an example will look for this file and, if found, will call ComparePDFFiles() to check the example PDF for equality with its reference PDF. If differences exist between the two files they will be printed to standard output and the test will fail. If the reference file is missing, the comparison is considered to succeed. In order to successfully compare two PDFs, the placement of internal resources must be consistent and the internal creation timestamps must be the same. To do this, the methods SetCatalogSort() and SetCreationDate() need to be called for both files. This is done automatically for all examples. Nothing special is required to use the standard PDF fonts (courier, helvetica, times, zapfdingbats) in your documents other than calling SetFont(). You should use AddUTF8Font() or AddUTF8FontFromBytes() to add a TrueType UTF-8 encoded font. Use RTL() and LTR() methods switch between “right-to-left” and “left-to-right” mode. In order to use a different non-UTF-8 TrueType or Type1 font, you will need to generate a font definition file and, if the font will be embedded into PDFs, a compressed version of the font file. This is done by calling the MakeFont function or using the included makefont command line utility. To create the utility, cd into the makefont subdirectory and run “go build”. This will produce a standalone executable named makefont. Select the appropriate encoding file from the font subdirectory and run the command as in the following example. In your PDF generation code, call AddFont() to load the font and, as with the standard fonts, SetFont() to begin using it. Most examples, including the package example, demonstrate this method. Good sources of free, open-source fonts include Google Fonts and DejaVu Fonts. The draw2d package is a two dimensional vector graphics library that can generate output in different forms. It uses gofpdf for its document production mode. gofpdf is a global community effort and you are invited to make it even better. If you have implemented a new feature or corrected a problem, please consider contributing your change to the project. A contribution that does not directly pertain to the core functionality of gofpdf should be placed in its own directory directly beneath the contrib directory. Here are guidelines for making submissions. Your change should - be compatible with the MIT License - be properly documented - be formatted with go fmt - include an example in fpdf_test.go if appropriate - conform to the standards of golint and go vet, that is, golint . and go vet . should not generate any warnings - not diminish test coverage Pull requests are the preferred means of accepting your changes. gofpdf is released under the MIT License. It is copyrighted by Kurt Jung and the contributors acknowledged below. This package’s code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Bruno Michel has provided valuable assistance with the code. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF transparency script by Martin Hall-May. Support for gradients and clipping is adapted from FPDF scripts by Andreas Würmser. Support for outline bookmarks is adapted from Olivier Plathey by Manuel Cornes. Layer support is adapted from Olivier Plathey. Support for transformations is adapted from the FPDF transformation script by Moritz Wagner and Andreas Würmser. PDF protection is adapted from the work of Klemen Vodopivec for the FPDF product. Lawrence Kesteloot provided code to allow an image’s extent to be determined prior to placement. Support for vertical alignment within a cell was provided by Stefan Schroeder. Ivan Daniluk generalized the font and image loading code to use the Reader interface while maintaining backward compatibility. Anthony Starks provided code for the Polygon function. Robert Lillack provided the Beziergon function and corrected some naming issues with the internal curve function. Claudio Felber provided implementations for dashed line drawing and generalized font loading. Stani Michiels provided support for multi-segment path drawing with smooth line joins, line join styles, enhanced fill modes, and has helped greatly with package presentation and tests. Templating is adapted by Marcus Downing from the FPDF_Tpl library created by Jan Slabon and Setasign. Jelmer Snoeck contributed packages that generate a variety of barcodes and help with registering images on the web. Jelmer Snoek and Guillermo Pascual augmented the basic HTML functionality with aligned text. Kent Quirk implemented backwards-compatible support for reading DPI from images that support it, and for setting DPI manually and then having it properly taken into account when calculating image size. Paulo Coutinho provided support for static embedded fonts. Dan Meyers added support for embedded JavaScript. David Fish added a generic alias-replacement function to enable, among other things, table of contents functionality. Andy Bakun identified and corrected a problem in which the internal catalogs were not sorted stably. Paul Montag added encoding and decoding functionality for templates, including images that are embedded in templates; this allows templates to be stored independently of gofpdf. Paul also added support for page boxes used in printing PDF documents. Wojciech Matusiak added supported for word spacing. Artem Korotkiy added support of UTF-8 fonts. Dave Barnes added support for imported objects and templates. Brigham Thompson added support for rounded rectangles. Joe Westcott added underline functionality and optimized image storage. Benoit KUGLER contributed support for rectangles with corners of unequal radius, modification times, and for file attachments and annotations. - Remove all legacy code page font support; use UTF-8 exclusively - Improve test coverage as reported by the coverage tool. Example demonstrates the generation of a simple PDF document. Note that since only core fonts are used (in this case Arial, a synonym for Helvetica), an empty string can be specified for the font directory in the call to New(). Note also that the example.Filename() and example.Summary() functions belong to a separate, internal package and are not part of the gofpdf library. If an error occurs at some point during the construction of the document, subsequent method calls exit immediately and the error is finally retrieved with the output call where it can be handled by the application.

Package tcell provides a lower-level, portable API for building programs that interact with terminals or consoles. It works with both common (and many uncommon!) terminals or terminal emulators, and Windows console implementations. It provides support for up to 256 colors, text attributes, and box drawing elements. A database of terminals built from a real terminfo database is provided, along with code to generate new database entries. Tcell offers very rich support for mice, dependent upon the terminal of course. (Windows, XTerm, and iTerm 2 are known to work very well.) If the environment is not Unicode by default, such as an ISO8859 based locale or GB18030, Tcell can convert input and output, so that your terminal can operate in whatever locale is most convenient, while the application program can just assume "everything is UTF-8". Reasonable defaults are used for updating characters to something suitable for display. Unicode box drawing characters will be converted to use the alternate character set of your terminal, if native conversions are not available. If no ACS is available, then some ASCII fallbacks will be used. Note that support for non-UTF-8 locales (other than C) must be enabled by the application using RegisterEncoding() -- we don't have them all enabled by default to avoid bloating the application unneccessarily. (These days UTF-8 is good enough for almost everyone, and nobody should be using legacy locales anymore.) Also, actual glyphs for various code point will only be displayed if your terminal or emulator (or the font the emulator is using) supports them. A rich set of keycodes is supported, with support for up to 65 function keys, and various other special keys.

Package log is a drop-in replacement for the standard Go logging library "log" which is fully source code compatible support all the standard library API while at the same time offering advanced logging features through an extended API. The design goals of gonelog was: Out of the box the default logger with package level methods works like the standard library *log.Logger with all the standard flags and methods: Under the hood the default *log.Logger is however a log context object which can have key/value data and which generate log events with a syslog level and hands them of to a log Handler for formatting and output. The default Logger supports all this as well, using log level constants source code compatible with the "log/syslog" package through the github.com/One-com/gone/log/syslog package: Logging with key/value data is (in its most simple form) done by calling level specific functions. First argument is the message, subsequenct arguments key/value data: Earch *log.Logger object has a current "log level" which determines the maximum log level for which events are actually generated. Logging above that level will be ignored. This log level can be controlled: Calling Fatal*() and Panic*() will in addition to Fataling/panicing log at level ALERT. The Print*() methods will log events with a configurable "default" log level - which default to INFO. Per default the Logger *will* generate log event for Print*() calls even though the log level is lower. The Logger can be set to respect the actual log level also for Print*() statements by the second argument to SetPrintLevel() A new custom Logger with its own behavior and formatting handler can be created: A customer Logger will not per default spend time timestamping events or registring file/line information. You have to enable that explicitly (it's not enabled by setting the flags on a formatting handler). When having key/value data which you need to have logged in all log events, but don't want to remember to put into every log statement, you can create a "child" Logger: To simply set the standard logger in a minimal mode where it only outputs <level>message to STDOUT and let an external daemon supervisor/log system do the rest (including timestamping) just do: Having many log statements can be expensive. Especially if the arguments to be logged are resource intensive to compute and there's no log events generated anyway. There are 2 ways to get around that. The first is do do Lazy evaluation of arguments: The other is to pick an comma-ok style log function: Sometimes it can be repetitive to make a lot of log statements logging many attributes of the same kinda of object by explicitly accessing every attribute. To make that simpler, every object can implement the Logable interface by creating a LogValues() function returning the attributes to be logged (with keys). The object can then be logged by directly providing it as an argument to a log function: Loggers can have names, placing them in a global "/" separated hierarchy. It's recommended to create a Logger by mentioning it by name using GetLogger("logger/name") - instead of creating unnamed Loggers with NewLogger(). If such a logger exists you will get it returned, so you can configure it and set the formatter/output. Otherwise a new logger by that name is created. Libraries are encouraged to published the names of their Loggers and to name Loggers after their Go package. This works exactly like the Python "logging" library - with one exception: When Logging an event at a Logger the tree of Loggers by name are only traversed towards to root to find the first Logger having a Handler attached, not returning an error. The log-event is then sent to that handler. If that handler returns an error, the parent Logger and its Handler is tried. This allows to contruct a "Last Resort" parent for errors in the default log Handler. The Python behaviour is to send the event to all Handlers found in the Logger tree. This is not the way it's done here. Only one Handler will be given the event to log. If you wan't more Handlers getting the event, use a MultiHandler. Happy logging.

Package siris is a fully-featured HTTP/2 backend web framework written entirely in Google’s Go Language. Source code and other details for the project are available at GitHub: The only requirement is the Go Programming Language, at least version 1.8 Example code: All HTTP methods are supported, developers can also register handlers for same paths for different methods. The first parameter is the HTTP Method, second parameter is the request path of the route, third variadic parameter should contains one or more context.Handler executed by the registered order when a user requests for that specific resouce path from the server. Example code: In order to make things easier for the user, Siris provides functions for all HTTP Methods. The first parameter is the request path of the route, second variadic parameter should contains one or more context.Handler executed by the registered order when a user requests for that specific resouce path from the server. Example code: A set of routes that are being groupped by path prefix can (optionally) share the same middleware handlers and template layout. A group can have a nested group too. `.Party` is being used to group routes, developers can declare an unlimited number of (nested) groups. Example code: Siris developers are able to register their own handlers for http statuses like 404 not found, 500 internal server error and so on. Example code: With the help of Siris's expressionist router you can build any form of API you desire, with safety. Example code: At the previous example, we've seen static routes, group of routes, subdomains, wildcard subdomains, a small example of parameterized path with a single known paramete and custom http errors, now it's time to see wildcard parameters and macros. Siris, like net/http std package registers route's handlers by a Handler, the Siris' type of handler is just a func(ctx context.Context) where context comes from github.com/go-siris/siris/context. Until go 1.9 you will have to import that package too, after go 1.9 this will be not be necessary. Siris has the easiest and the most powerful routing process you have ever meet. At the same time, Siris has its own interpeter(yes like a programming language) for route's path syntax and their dynamic path parameters parsing and evaluation, I am calling them "macros" for shortcut. How? It calculates its needs and if not any special regexp needed then it just registers the route with the low-level path syntax, otherwise it pre-compiles the regexp and adds the necessary middleware(s). Standard macro types for parameters: if type is missing then parameter's type is defaulted to string, so {param} == {param:string}. If a function not found on that type then the "string"'s types functions are being used. i.e: Besides the fact that Siris provides the basic types and some default "macro funcs" you are able to register your own too!. Register a named path parameter function: at the func(argument ...) you can have any standard type, it will be validated before the server starts so don't care about performance here, the only thing it runs at serve time is the returning func(paramValue string) bool. Example code: A path parameter name should contain only alphabetical letters, symbols, containing '_' and numbers are NOT allowed. If route failed to be registered, the app will panic without any warnings if you didn't catch the second return value(error) on .Handle/.Get.... Last, do not confuse ctx.Values() with ctx.Params(). Path parameter's values goes to ctx.Params() and context's local storage that can be used to communicate between handlers and middleware(s) goes to ctx.Values(), path parameters and the rest of any custom values are separated for your own good. Run Static Files Example code: More examples can be found here: https://github.com/go-siris/siris/tree/master/_examples/beginner/file-server Middleware is just a concept of ordered chain of handlers. Middleware can be registered globally, per-party, per-subdomain and per-route. Example code: Siris is able to wrap and convert any external, third-party Handler you used to use to your web application. Let's convert the https://github.com/rs/cors net/http external middleware which returns a `next form` handler. Example code: Siris supports 5 template engines out-of-the-box, developers can still use any external golang template engine, as `context.ResponseWriter()` is an `io.Writer`. All of these five template engines have common features with common API, like Layout, Template Funcs, Party-specific layout, partial rendering and more. Example code: View engine supports bundled(https://github.com/jteeuwen/go-bindata) template files too. go-bindata gives you two functions, asset and assetNames, these can be setted to each of the template engines using the `.Binary` func. Example code: A real example can be found here: https://github.com/go-siris/siris/tree/master/_examples/intermediate/view/embedding-templates-into-app. Enable auto-reloading of templates on each request. Useful while developers are in dev mode as they no neeed to restart their app on every template edit. Example code: Each one of these template engines has different options located here: https://github.com/go-siris/siris/tree/master/view . This example will show how to store and access data from a session. You don’t need any third-party library, but If you want you can use any session manager compatible or not. In this example we will only allow authenticated users to view our secret message on the /secret page. To get access to it, the will first have to visit /login to get a valid session cookie, which logs him in. Additionally he can visit /logout to revoke his access to our secret message. Example code: Running the example: But you should have a basic idea of the framework by now, we just scratched the surface. If you enjoy what you just saw and want to learn more, please follow the below links: Examples: Built'n Middleware: Community Middleware: Home Page:

Package siris is a fully-featured HTTP/2 backend web framework written entirely in Google’s Go Language. Source code and other details for the project are available at GitHub: The only requirement is the Go Programming Language, at least version 1.8 Example code: All HTTP methods are supported, developers can also register handlers for same paths for different methods. The first parameter is the HTTP Method, second parameter is the request path of the route, third variadic parameter should contains one or more context.Handler executed by the registered order when a user requests for that specific resouce path from the server. Example code: In order to make things easier for the user, Siris provides functions for all HTTP Methods. The first parameter is the request path of the route, second variadic parameter should contains one or more context.Handler executed by the registered order when a user requests for that specific resouce path from the server. Example code: A set of routes that are being groupped by path prefix can (optionally) share the same middleware handlers and template layout. A group can have a nested group too. `.Party` is being used to group routes, developers can declare an unlimited number of (nested) groups. Example code: Siris developers are able to register their own handlers for http statuses like 404 not found, 500 internal server error and so on. Example code: With the help of Siris's expressionist router you can build any form of API you desire, with safety. Example code: At the previous example, we've seen static routes, group of routes, subdomains, wildcard subdomains, a small example of parameterized path with a single known paramete and custom http errors, now it's time to see wildcard parameters and macros. Siris, like net/http std package registers route's handlers by a Handler, the Siris' type of handler is just a func(ctx context.Context) where context comes from github.com/go-siris/siris/context. Until go 1.9 you will have to import that package too, after go 1.9 this will be not be necessary. Siris has the easiest and the most powerful routing process you have ever meet. At the same time, Siris has its own interpeter(yes like a programming language) for route's path syntax and their dynamic path parameters parsing and evaluation, I am calling them "macros" for shortcut. How? It calculates its needs and if not any special regexp needed then it just registers the route with the low-level path syntax, otherwise it pre-compiles the regexp and adds the necessary middleware(s). Standard macro types for parameters: if type is missing then parameter's type is defaulted to string, so {param} == {param:string}. If a function not found on that type then the "string"'s types functions are being used. i.e: Besides the fact that Siris provides the basic types and some default "macro funcs" you are able to register your own too!. Register a named path parameter function: at the func(argument ...) you can have any standard type, it will be validated before the server starts so don't care about performance here, the only thing it runs at serve time is the returning func(paramValue string) bool. Example code: A path parameter name should contain only alphabetical letters, symbols, containing '_' and numbers are NOT allowed. If route failed to be registered, the app will panic without any warnings if you didn't catch the second return value(error) on .Handle/.Get.... Last, do not confuse ctx.Values() with ctx.Params(). Path parameter's values goes to ctx.Params() and context's local storage that can be used to communicate between handlers and middleware(s) goes to ctx.Values(), path parameters and the rest of any custom values are separated for your own good. Run Static Files Example code: More examples can be found here: https://github.com/go-siris/siris/tree/master/_examples/beginner/file-server Middleware is just a concept of ordered chain of handlers. Middleware can be registered globally, per-party, per-subdomain and per-route. Example code: Siris is able to wrap and convert any external, third-party Handler you used to use to your web application. Let's convert the https://github.com/rs/cors net/http external middleware which returns a `next form` handler. Example code: Siris supports 5 template engines out-of-the-box, developers can still use any external golang template engine, as `context.ResponseWriter()` is an `io.Writer`. All of these five template engines have common features with common API, like Layout, Template Funcs, Party-specific layout, partial rendering and more. Example code: View engine supports bundled(https://github.com/jteeuwen/go-bindata) template files too. go-bindata gives you two functions, asset and assetNames, these can be setted to each of the template engines using the `.Binary` func. Example code: A real example can be found here: https://github.com/go-siris/siris/tree/master/_examples/intermediate/view/embedding-templates-into-app. Enable auto-reloading of templates on each request. Useful while developers are in dev mode as they no neeed to restart their app on every template edit. Example code: Each one of these template engines has different options located here: https://github.com/go-siris/siris/tree/master/view . This example will show how to store and access data from a session. You don’t need any third-party library, but If you want you can use any session manager compatible or not. In this example we will only allow authenticated users to view our secret message on the /secret page. To get access to it, the will first have to visit /login to get a valid session cookie, which logs him in. Additionally he can visit /logout to revoke his access to our secret message. Example code: Running the example: But you should have a basic idea of the framework by now, we just scratched the surface. If you enjoy what you just saw and want to learn more, please follow the below links: Examples: Built'n Middleware: Community Middleware: Home Page:

Package gofpdf implements a PDF document generator with high level support for text, drawing and images. - UTF-8 support - Choice of measurement unit, page format and margins - Page header and footer management - Automatic page breaks, line breaks, and text justification - Inclusion of JPEG, PNG, GIF, TIFF and basic path-only SVG images - Colors, gradients and alpha channel transparency - Outline bookmarks - Internal and external links - TrueType, Type1 and encoding support - Page compression - Lines, Bézier curves, arcs, and ellipses - Rotation, scaling, skewing, translation, and mirroring - Clipping - Document protection - Layers - Templates - Barcodes - Charting facility - Import PDFs as templates gofpdf has no dependencies other than the Go standard library. All tests pass on Linux, Mac and Windows platforms. gofpdf supports UTF-8 TrueType fonts and “right-to-left” languages. Note that Chinese, Japanese, and Korean characters may not be included in many general purpose fonts. For these languages, a specialized font (for example, NotoSansSC for simplified Chinese) can be used. Also, support is provided to automatically translate UTF-8 runes to code page encodings for languages that have fewer than 256 glyphs. This repository will not be maintained, at least for some unknown duration. But it is hoped that gofpdf has a bright future in the open source world. Due to Go’s promise of compatibility, gofpdf should continue to function without modification for a longer time than would be the case with many other languages. Forks should be based on the last viable commit. Tools such as active-forks can be used to select a fork that looks promising for your needs. If a particular fork looks like it has taken the lead in attracting followers, this README will be updated to point people in that direction. The efforts of all contributors to this project have been deeply appreciated. Best wishes to all of you. To install the package on your system, run Later, to receive updates, run The following Go code generates a simple PDF file. See the functions in the fpdf_test.go file (shown as examples in this documentation) for more advanced PDF examples. If an error occurs in an Fpdf method, an internal error field is set. After this occurs, Fpdf method calls typically return without performing any operations and the error state is retained. This error management scheme facilitates PDF generation since individual method calls do not need to be examined for failure; it is generally sufficient to wait until after Output() is called. For the same reason, if an error occurs in the calling application during PDF generation, it may be desirable for the application to transfer the error to the Fpdf instance by calling the SetError() method or the SetErrorf() method. At any time during the life cycle of the Fpdf instance, the error state can be determined with a call to Ok() or Err(). The error itself can be retrieved with a call to Error(). This package is a relatively straightforward translation from the original FPDF library written in PHP (despite the caveat in the introduction to Effective Go). The API names have been retained even though the Go idiom would suggest otherwise (for example, pdf.GetX() is used rather than simply pdf.X()). The similarity of the two libraries makes the original FPDF website a good source of information. It includes a forum and FAQ. However, some internal changes have been made. Page content is built up using buffers (of type bytes.Buffer) rather than repeated string concatenation. Errors are handled as explained above rather than panicking. Output is generated through an interface of type io.Writer or io.WriteCloser. A number of the original PHP methods behave differently based on the type of the arguments that are passed to them; in these cases additional methods have been exported to provide similar functionality. Font definition files are produced in JSON rather than PHP. A side effect of running go test ./... is the production of a number of example PDFs. These can be found in the gofpdf/pdf directory after the tests complete. Please note that these examples run in the context of a test. In order run an example as a standalone application, you’ll need to examine fpdf_test.go for some helper routines, for example exampleFilename() and summary(). Example PDFs can be compared with reference copies in order to verify that they have been generated as expected. This comparison will be performed if a PDF with the same name as the example PDF is placed in the gofpdf/pdf/reference directory and if the third argument to ComparePDFFiles() in internal/example/example.go is true. (By default it is false.) The routine that summarizes an example will look for this file and, if found, will call ComparePDFFiles() to check the example PDF for equality with its reference PDF. If differences exist between the two files they will be printed to standard output and the test will fail. If the reference file is missing, the comparison is considered to succeed. In order to successfully compare two PDFs, the placement of internal resources must be consistent and the internal creation timestamps must be the same. To do this, the methods SetCatalogSort() and SetCreationDate() need to be called for both files. This is done automatically for all examples. Nothing special is required to use the standard PDF fonts (courier, helvetica, times, zapfdingbats) in your documents other than calling SetFont(). You should use AddUTF8Font() or AddUTF8FontFromBytes() to add a TrueType UTF-8 encoded font. Use RTL() and LTR() methods switch between “right-to-left” and “left-to-right” mode. In order to use a different non-UTF-8 TrueType or Type1 font, you will need to generate a font definition file and, if the font will be embedded into PDFs, a compressed version of the font file. This is done by calling the MakeFont function or using the included makefont command line utility. To create the utility, cd into the makefont subdirectory and run “go build”. This will produce a standalone executable named makefont. Select the appropriate encoding file from the font subdirectory and run the command as in the following example. In your PDF generation code, call AddFont() to load the font and, as with the standard fonts, SetFont() to begin using it. Most examples, including the package example, demonstrate this method. Good sources of free, open-source fonts include Google Fonts and DejaVu Fonts. The draw2d package is a two dimensional vector graphics library that can generate output in different forms. It uses gofpdf for its document production mode. gofpdf is a global community effort and you are invited to make it even better. If you have implemented a new feature or corrected a problem, please consider contributing your change to the project. A contribution that does not directly pertain to the core functionality of gofpdf should be placed in its own directory directly beneath the contrib directory. Here are guidelines for making submissions. Your change should - be compatible with the MIT License - be properly documented - be formatted with go fmt - include an example in fpdf_test.go if appropriate - conform to the standards of golint and go vet, that is, golint . and go vet . should not generate any warnings - not diminish test coverage Pull requests are the preferred means of accepting your changes. gofpdf is released under the MIT License. It is copyrighted by Kurt Jung and the contributors acknowledged below. This package’s code and documentation are closely derived from the FPDF library created by Olivier Plathey, and a number of font and image resources are copied directly from it. Bruno Michel has provided valuable assistance with the code. Drawing support is adapted from the FPDF geometric figures script by David Hernández Sanz. Transparency support is adapted from the FPDF transparency script by Martin Hall-May. Support for gradients and clipping is adapted from FPDF scripts by Andreas Würmser. Support for outline bookmarks is adapted from Olivier Plathey by Manuel Cornes. Layer support is adapted from Olivier Plathey. Support for transformations is adapted from the FPDF transformation script by Moritz Wagner and Andreas Würmser. PDF protection is adapted from the work of Klemen Vodopivec for the FPDF product. Lawrence Kesteloot provided code to allow an image’s extent to be determined prior to placement. Support for vertical alignment within a cell was provided by Stefan Schroeder. Ivan Daniluk generalized the font and image loading code to use the Reader interface while maintaining backward compatibility. Anthony Starks provided code for the Polygon function. Robert Lillack provided the Beziergon function and corrected some naming issues with the internal curve function. Claudio Felber provided implementations for dashed line drawing and generalized font loading. Stani Michiels provided support for multi-segment path drawing with smooth line joins, line join styles, enhanced fill modes, and has helped greatly with package presentation and tests. Templating is adapted by Marcus Downing from the FPDF_Tpl library created by Jan Slabon and Setasign. Jelmer Snoeck contributed packages that generate a variety of barcodes and help with registering images on the web. Jelmer Snoek and Guillermo Pascual augmented the basic HTML functionality with aligned text. Kent Quirk implemented backwards-compatible support for reading DPI from images that support it, and for setting DPI manually and then having it properly taken into account when calculating image size. Paulo Coutinho provided support for static embedded fonts. Dan Meyers added support for embedded JavaScript. David Fish added a generic alias-replacement function to enable, among other things, table of contents functionality. Andy Bakun identified and corrected a problem in which the internal catalogs were not sorted stably. Paul Montag added encoding and decoding functionality for templates, including images that are embedded in templates; this allows templates to be stored independently of gofpdf. Paul also added support for page boxes used in printing PDF documents. Wojciech Matusiak added supported for word spacing. Artem Korotkiy added support of UTF-8 fonts. Dave Barnes added support for imported objects and templates. Brigham Thompson added support for rounded rectangles. Joe Westcott added underline functionality and optimized image storage. Benoit KUGLER contributed support for rectangles with corners of unequal radius, modification times, and for file attachments and annotations. - Remove all legacy code page font support; use UTF-8 exclusively - Improve test coverage as reported by the coverage tool. Example demonstrates the generation of a simple PDF document. Note that since only core fonts are used (in this case Arial, a synonym for Helvetica), an empty string can be specified for the font directory in the call to New(). Note also that the example.Filename() and example.Summary() functions belong to a separate, internal package and are not part of the gofpdf library. If an error occurs at some point during the construction of the document, subsequent method calls exit immediately and the error is finally retrieved with the output call where it can be handled by the application.

Package Rye is a simple library to support http services. Rye provides a middleware handler which can be used to chain http handlers together while providing simple statsd metrics for use with a monitoring solution such as DataDog or other logging aggregators. Rye also provides some additional middleware handlers that are entirely optional but easily consumed using Rye. In order to use rye, you should vendor it and the statsd client within your project. Begin by importing the required libraries: Create a statsd client (if desired) and create a rye Config in order to pass in optional dependencies: Create a middleware handler. The purpose of the Handler is to keep Config and to provide an interface for chaining http handlers. Build your http handlers using the Handler type from the **rye** package. Here are some example (custom) handlers: Finally, to setup your handlers in your API Rye comes with built-in configurable `statsd` statistics that you could record to your favorite monitoring system. To configure that, you'll need to set up a `Statter` based on the `github.com/cactus/go-statsd-client` and set it in your instantiation of `MWHandler` through the `rye.Config`. When a middleware is called, it's timing is recorded and a counter is recorded associated directly with the http status code returned during the call. Additionally, an `errors` counter is also sent to the statter which allows you to count any errors that occur with a code equaling or above 500. Example: If you have a middleware handler you've created with a method named `loginHandler`, successful calls to that will be recorded to `handlers.loginHandler.2xx`. Additionally you'll receive stats such as `handlers.loginHandler.400` or `handlers.loginHandler.500`. You also will receive an increase in the `errors` count. If you're sending your logs into a system such as DataDog, be aware that your stats from Rye can have prefixes such as `statsd.my-service.my-k8s-cluster.handlers.loginHandler.2xx` or even `statsd.my-service.my-k8s-cluster.errors`. Just keep in mind your stats could end up in the destination sink system with prefixes. With Golang 1.7, a new feature has been added that supports a request specific context. This is a great feature that Rye supports out-of-the-box. The tricky part of this is how the context is modified on the request. In Golang, the Context is always available on a Request through `http.Request.Context()`. Great! However, if you want to add key/value pairs to the context, you will have to add the context to the request before it gets passed to the next Middleware. To support this, the `rye.Response` has a property called `Context`. This property takes a properly created context (pulled from the `request.Context()` function. When you return a `rye.Response` which has `Context`, the **rye** library will craft a new Request and make sure that the next middleware receives that request. Here's the details of creating a middleware with a proper `Context`. You must first pull from the current request `Context`. In the example below, you see `ctx := r.Context()`. That pulls the current context. Then, you create a NEW context with your additional context key/value. Finally, you return `&rye.Response{Context:ctx}` Now in a later middleware, you can easily retrieve the value you set! For another simple example, look in the JWT middleware - it adds the JWT into the context for use by other middlewares. It uses the `CONTEXT_JWT` key to push the JWT token into the `Context`. Rye comes with various pre-built middleware handlers. Pre-built middlewares source (and docs) can be found in the package dir following the pattern `middleware_*.go`. To use them, specify the constructor of the middleware as one of the middleware handlers when you define your routes: OR The JWT Middleware pushes the JWT token onto the Context for use by other middlewares in the chain. This is a convenience that allows any part of your middleware chain quick access to the JWT. Example usage might include a middleware that needs access to your user id or email address stored in the JWT. To access this `Context` variable, the code is very simple:

Package Rye is a simple library to support http services. Rye provides a middleware handler which can be used to chain http handlers together while providing simple statsd metrics for use with a monitoring solution such as DataDog or other logging aggregators. Rye also provides some additional middleware handlers that are entirely optional but easily consumed using Rye. In order to use rye, you should vendor it and the statsd client within your project. Begin by importing the required libraries: Create a statsd client (if desired) and create a rye Config in order to pass in optional dependencies: Create a middleware handler. The purpose of the Handler is to keep Config and to provide an interface for chaining http handlers. Build your http handlers using the Handler type from the **rye** package. Here are some example (custom) handlers: Finally, to setup your handlers in your API Rye comes with built-in configurable `statsd` statistics that you could record to your favorite monitoring system. To configure that, you'll need to set up a `Statter` based on the `github.com/cactus/go-statsd-client` and set it in your instantiation of `MWHandler` through the `rye.Config`. When a middleware is called, it's timing is recorded and a counter is recorded associated directly with the http status code returned during the call. Additionally, an `errors` counter is also sent to the statter which allows you to count any errors that occur with a code equaling or above 500. Example: If you have a middleware handler you've created with a method named `loginHandler`, successful calls to that will be recorded to `handlers.loginHandler.2xx`. Additionally you'll receive stats such as `handlers.loginHandler.400` or `handlers.loginHandler.500`. You also will receive an increase in the `errors` count. If you're sending your logs into a system such as DataDog, be aware that your stats from Rye can have prefixes such as `statsd.my-service.my-k8s-cluster.handlers.loginHandler.2xx` or even `statsd.my-service.my-k8s-cluster.errors`. Just keep in mind your stats could end up in the destination sink system with prefixes. With Golang 1.7, a new feature has been added that supports a request specific context. This is a great feature that Rye supports out-of-the-box. The tricky part of this is how the context is modified on the request. In Golang, the Context is always available on a Request through `http.Request.Context()`. Great! However, if you want to add key/value pairs to the context, you will have to add the context to the request before it gets passed to the next Middleware. To support this, the `rye.Response` has a property called `Context`. This property takes a properly created context (pulled from the `request.Context()` function. When you return a `rye.Response` which has `Context`, the **rye** library will craft a new Request and make sure that the next middleware receives that request. Here's the details of creating a middleware with a proper `Context`. You must first pull from the current request `Context`. In the example below, you see `ctx := r.Context()`. That pulls the current context. Then, you create a NEW context with your additional context key/value. Finally, you return `&rye.Response{Context:ctx}` Now in a later middleware, you can easily retrieve the value you set! For another simple example, look in the JWT middleware - it adds the JWT into the context for use by other middlewares. It uses the `CONTEXT_JWT` key to push the JWT token into the `Context`. Rye comes with various pre-built middleware handlers. Pre-built middlewares source (and docs) can be found in the package dir following the pattern `middleware_*.go`. To use them, specify the constructor of the middleware as one of the middleware handlers when you define your routes: OR The JWT Middleware pushes the JWT token onto the Context for use by other middlewares in the chain. This is a convenience that allows any part of your middleware chain quick access to the JWT. Example usage might include a middleware that needs access to your user id or email address stored in the JWT. To access this `Context` variable, the code is very simple:

Package order enables easier ordering and comparison tasks. This package provides functionality to easily define and apply order on values. It works out of the box for most primitive types and their pointer versions, and enable order of any object using (three-way comparison) https://en.wikipedia.org/wiki/Three-way_comparison with a given `func(T, T) int` function, or by implementing the generic interface: `func (T) Compare(T) int`. Supported Tasks: * [x] `Sort` / `SortStable` - sort a slice. * [x] `Search` - binary search for a value in a slice. * [x] `MinMax` - get indices of minimal and maximal values of a slice. * [X] `Is` - get a comparable object for more readable code. + [x] `Select` - get the K'th greatest value of a slice. * [x] `IsSorted` / `IsStrictSorted` - check if a slice is sorted. Order between values can be more forgiving than strict comparison. This library allows sensible type conversions. A type `U` can be used in order function of type `T` in the following cases: * `U` is a pointer (or pointers chain) to a `T`. * `T` is a pointer (or pointers chain) to a `U`. * `T` and `U` are of the same kind. * `T` and `U` are of the same number kind group (int?, uint?, float?, complex?) and `U`'s bits number is less or equal to `T`'s bits number. * `U` and `T` are assignable structs. Using this library might be less type safe - because of the usage of interfaces API, and less efficient - because of the use of reflection. On the other hand, this library reduce chances for errors by providing a well tested code and more readable code. See below how some order tasks can be translated to be used by this library. A simple example that shows how to use the order library with different basic types. A type may implement a `func (t T) Compare(other T) int` function. In this case it could be just used with the order package functions. An example of ordering struct with multiple fields with different priorities.

Package log is a drop-in replacement for the standard Go logging library "log" which is fully source code compatible support all the standard library API while at the same time offering advanced logging features through an extended API. The design goals of gonelog was: Out of the box the default logger with package level methods works like the standard library *log.Logger with all the standard flags and methods: Under the hood the default *log.Logger is however a log context object which can have key/value data and which generate log events with a syslog level and hands them of to a log Handler for formatting and output. The default Logger supports all this as well, using log level constants source code compatible with the "log/syslog" package through the github.com/One-com/gone/log/syslog package: Logging with key/value data is (in its most simple form) done by calling level specific functions. First argument is the message, subsequenct arguments key/value data: Earch *log.Logger object has a current "log level" which determines the maximum log level for which events are actually generated. Logging above that level will be ignored. This log level can be controlled: Calling Fatal*() and Panic*() will in addition to Fataling/panicing log at level ALERT. The Print*() methods will log events with a configurable "default" log level - which default to INFO. Per default the Logger *will* generate log event for Print*() calls even though the log level is lower. The Logger can be set to respect the actual log level also for Print*() statements by the second argument to SetPrintLevel() A new custom Logger with its own behavior and formatting handler can be created: A customer Logger will not per default spend time timestamping events or registring file/line information. You have to enable that explicitly (it's not enabled by setting the flags on a formatting handler). When having key/value data which you need to have logged in all log events, but don't want to remember to put into every log statement, you can create a "child" Logger: To simply set the standard logger in a minimal mode where it only outputs <level>message to STDOUT and let an external daemon supervisor/log system do the rest (including timestamping) just do: Having many log statements can be expensive. Especially if the arguments to be logged are resource intensive to compute and there's no log events generated anyway. There are 2 ways to get around that. The first is do do Lazy evaluation of arguments: The other is to pick an comma-ok style log function: Sometimes it can be repetitive to make a lot of log statements logging many attributes of the same kinda of object by explicitly accessing every attribute. To make that simpler, every object can implement the Logable interface by creating a LogValues() function returning the attributes to be logged (with keys). The object can then be logged by directly providing it as an argument to a log function: Loggers can have names, placing them in a global "/" separated hierarchy. It's recommended to create a Logger by mentioning it by name using GetLogger("logger/name") - instead of creating unnamed Loggers with NewLogger(). If such a logger exists you will get it returned, so you can configure it and set the formatter/output. Otherwise a new logger by that name is created. Libraries are encouraged to published the names of their Loggers and to name Loggers after their Go package. This works exactly like the Python "logging" library - with one exception: When Logging an event at a Logger the tree of Loggers by name are only traversed towards to root to find the first Logger having a Handler attached, not returning an error. The log-event is then sent to that handler. If that handler returns an error, the parent Logger and its Handler is tried. This allows to contruct a "Last Resort" parent for errors in the default log Handler. The Python behaviour is to send the event to all Handlers found in the Logger tree. This is not the way it's done here. Only one Handler will be given the event to log. If you wan't more Handlers getting the event, use a MultiHandler. Happy logging.

Package Rye is a simple library to support http services. Rye provides a middleware handler which can be used to chain http handlers together while providing simple statsd metrics for use with a monitoring solution such as DataDog or other logging aggregators. Rye also provides some additional middleware handlers that are entirely optional but easily consumed using Rye. In order to use rye, you should vendor it and the statsd client within your project. Begin by importing the required libraries: Create a statsd client (if desired) and create a rye Config in order to pass in optional dependencies: Create a middleware handler. The purpose of the Handler is to keep Config and to provide an interface for chaining http handlers. Build your http handlers using the Handler type from the **rye** package. Here are some example (custom) handlers: Finally, to setup your handlers in your API Rye comes with built-in configurable `statsd` statistics that you could record to your favorite monitoring system. To configure that, you'll need to set up a `Statter` based on the `github.com/cactus/go-statsd-client` and set it in your instantiation of `MWHandler` through the `rye.Config`. When a middleware is called, it's timing is recorded and a counter is recorded associated directly with the http status code returned during the call. Additionally, an `errors` counter is also sent to the statter which allows you to count any errors that occur with a code equaling or above 500. Example: If you have a middleware handler you've created with a method named `loginHandler`, successful calls to that will be recorded to `handlers.loginHandler.2xx`. Additionally you'll receive stats such as `handlers.loginHandler.400` or `handlers.loginHandler.500`. You also will receive an increase in the `errors` count. If you're sending your logs into a system such as DataDog, be aware that your stats from Rye can have prefixes such as `statsd.my-service.my-k8s-cluster.handlers.loginHandler.2xx` or even `statsd.my-service.my-k8s-cluster.errors`. Just keep in mind your stats could end up in the destination sink system with prefixes. With Golang 1.7, a new feature has been added that supports a request specific context. This is a great feature that Rye supports out-of-the-box. The tricky part of this is how the context is modified on the request. In Golang, the Context is always available on a Request through `http.Request.Context()`. Great! However, if you want to add key/value pairs to the context, you will have to add the context to the request before it gets passed to the next Middleware. To support this, the `rye.Response` has a property called `Context`. This property takes a properly created context (pulled from the `request.Context()` function. When you return a `rye.Response` which has `Context`, the **rye** library will craft a new Request and make sure that the next middleware receives that request. Here's the details of creating a middleware with a proper `Context`. You must first pull from the current request `Context`. In the example below, you see `ctx := r.Context()`. That pulls the current context. Then, you create a NEW context with your additional context key/value. Finally, you return `&rye.Response{Context:ctx}` Now in a later middleware, you can easily retrieve the value you set! For another simple example, look in the JWT middleware - it adds the JWT into the context for use by other middlewares. It uses the `CONTEXT_JWT` key to push the JWT token into the `Context`. Rye comes with various pre-built middleware handlers. Pre-built middlewares source (and docs) can be found in the package dir following the pattern `middleware_*.go`. To use them, specify the constructor of the middleware as one of the middleware handlers when you define your routes: OR The JWT Middleware pushes the JWT token onto the Context for use by other middlewares in the chain. This is a convenience that allows any part of your middleware chain quick access to the JWT. Example usage might include a middleware that needs access to your user id or email address stored in the JWT. To access this `Context` variable, the code is very simple: