logdown

What is logdown?

Logdown is a JavaScript logging library that provides a simple and colorful way to log messages in the browser console. It supports different log levels, custom prefixes, and styles to make debugging easier and more visually appealing.

What are logdown's main functionalities?

Basic Logging

Logdown allows you to create a logger instance with a custom prefix and log messages to the console.

const logger = require('logdown')('myLogger');
logger.log('This is a log message');

Log Levels

Logdown supports different log levels such as info, warn, and error to categorize the importance of messages.

const logger = require('logdown')('myLogger');
logger.info('This is an info message');
logger.warn('This is a warning message');
logger.error('This is an error message');

Custom Styles

You can customize the appearance of log messages by setting styles such as prefix color and markdown support.

const logger = require('logdown')('myLogger');
logger.state = { prefixColor: 'blue', markdown: false };
logger.log('This is a styled log message');

Grouping Logs

Logdown allows you to group related log messages together, making it easier to organize and read logs.

const logger = require('logdown')('myLogger');
logger.group('Group 1');
logger.log('Message inside group 1');
logger.groupEnd('Group 1');

Other packages similar to logdown

winston

Winston is a versatile logging library for Node.js that supports multiple transports, log levels, and formats. Unlike Logdown, Winston is more suitable for server-side logging and offers advanced features like log rotation and custom transports.

bunyan

Bunyan is another powerful logging library for Node.js that focuses on JSON logging. It provides a simple API, log levels, and supports streams for log output. Bunyan is more geared towards server-side applications and structured logging compared to Logdown's browser-focused approach.

pino

Pino is a fast and lightweight logging library for Node.js that emphasizes performance. It supports log levels, custom serializers, and transports. Pino is designed for high-performance server-side logging, whereas Logdown is more focused on providing a colorful and user-friendly logging experience in the browser.

README

logdown.js

Logdown is a debug utility for the browser and the server with Markdown support. It does not have any dependencies and is only 2K gzipped.

You can see it in action in the example page or in the preview below.

Preview

Browser

Server

Using

The simplest use of the library in both platforms could be done as follows:

Node.js

If on the server, install it through npm:

npm install --save logdown

var Logdown = require('logdown')
var logger = new Logdown({prefix: 'foo'})

Browser

In the browser you can install it through Bower.

bower install logdown

var logger = new Logdown({prefix: 'foo'})

SystemJS

Using the dynamic module loader SystemJS, Logdown can be loaded as a CommonJS module.

SystemJS.config({
  map: {
    'logdown': 'bower_components/logdown/dist/index.js'
  },
  packages: {
    'logdown': {format: 'cjs'}
  }
});

System.import('logdown').then(function(Logdown) {
  var logger = new Logdown({prefix: 'foo'}
});

Other

You can also use the lib in the browser in the same way as in the server if you use Browserify. Or you can just download it here and put the dist/index.js file in your public folder.

Usage

It is highly recommended to use a prefix for your instance, this way you get a nice prefixed message on console and it is possible to silence instances based on the prefix name, as we will see after.

After creating your object, you can use the regular log, warn, info and error methods as we have on console, but now with Markdown support.

logger.log('lorem *ipsum*')
logger.info('dolor _sit_ amet')
logger.warn('consectetur `adipiscing` elit')

You can pass multiple arguments

logger.log('lorem', '*ipsum*')
logger.info('dolor _sit_', 'amet')
logger.warn('consectetur', '`adipiscing` elit')

New objects

The constructor accepts one object for configuration on instantiation time.

opts.prefix

Type: 'String'

Default: ''

var logger = new Logdown({prefix: 'foo'})
logger.log('Lorem ipsum') // Will use console.log with a prefix

You should use the name of your module. You can, also, use : to separate modules inside one big module.

var fooBarLogger = new Logdown({prefix: 'foo:bar'})
fooBarLogger.log('Lorem ipsum')

var fooQuzLogger = new Logdown({prefix: 'foo:quz'})
fooQuzLogger.log('Lorem Ipsum')

opts.markdown

Type: 'Boolean'

Default: true

If setted to false, markdown will not be parsed.

var logger = new Logdown({markdown: false})
logger.log('Lorem *ipsum*') // Will not parse the markdown

For Markdown, the following mark-up is supported:

// Bold with "*"" between words
logger.log('lorem *ipsum*')

// Italic with "_" between words
logger.log('lorem _ipsum_')

// Code with ` (backtick) between words
logger.log('lorem `ipsum`')

opts.alignOutput

Type: 'Boolean'

Default: false

If setted to true, the name of the logger instance will have the same length as the longest name of any other Logdown instance.

Enabling/disabling instances

It is possible to enable/disable the output of instances using the Logdown.disable or Logdown.enable methods.

Logdown.disable('foo') // will disable the instance with *foo* prefix
Logdown.enable('bar') // will enable the instance with *bar* prefix

You can also use wildcards.

Logdown.enable('*') // enables all instances
Logdown.disable('*') // disables all instances
Logdown.enable('foo*') // enables all instances with a prefix starting with *foo*

Use - to do a negation.

// enables all instances but the one with *foo* prefix
Logdown.enable('*', '-foo')
// disables all intances with foo in the prefix, but don't disable *foobar*
Logdown.disable('*foo*', '-foobar')

Support

Desktop browsers

Latest	9+	Latest	Latest	Latest	Latest	Latest

Mobile browsers

| | | | | | | | | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Latest | 6+ | 4.0+ | 8+ | Latest | Latest | Latest |

Server

0.10+ ✔

Credits

• Moleskine icon by Monika Ciapala
• Markdown icon by Dustin Curtis

Contributors

143  Caio Gondim
  4  David Godfrey
  2  Sven Anders Robbestad
  1  Dan Lukinykh
  1  Bent Cardan
  1  Gleb Bahmutov
  1  netmml

Donating

If you found this library useful and are willing to donate, transfer some bitcoins to 1BqqKiZA8Tq43CdukdBEwCdDD42jxuX9UY or through the URL https://www.coinbase.com/caiogondim

Or via PayPal.me https://www.paypal.me/caiogondim.

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