HTTP, Please
There are a lot of JS libraries for making HTTP requests in JavaScript. Why use
this one? Because it's awesome, that's why. And this is why it's awesome:
- Designed for "isomorphic" JavaScript (supporting both client and server
with the same codebase)
- …but with a browser-driven focus that keeps in mind the limitations of
that environment (filesize, old IE)
- Extensible via a simple but powerful plugin system (which it dogfoods)
browserify and webpack users can simply npm install httpplease
.
Bower users can bower install httpplease
.
<script>
tag fans can grab the standalone build from the "browser-builds"
directory.
Minified and gzipped, the standalone browser build is <2K.
API
Making a request
httpplease.get('http://example.com', function (err, res) {
});
Alternatively, you can pass a request options object as the first parameter:
httpplease.get({url: 'http://example.com'}, function (err, res) {
});
If you'd rather include the method in the object, that's okay too:
httpplease({method: 'GET', url: 'http://example.com'}, function (err, res) {
});
You can create a new http function with default request object values:
var http = httpplease.defaults({method: 'GET', errorOn404: false});
http('http://example.com', function (err, res) {
});
The request object
When you call one of the http functions (http
, http.get
, etc.), the result
is a Request object. This object can also be processed by plugins.
It has the same properties as the request options object you pass to the http
function (though properties that you didn't pass will be filled by defaults).
Those properties are:
Name | Description |
---|
url | The URL to request. |
method | The HTTP method to use for the request. |
body | The body to send with the request. |
headers |
An object containing HTTP headers to send, for example:
{Accept: '*/*'} .
|
timeout |
The number of milliseconds to wait before canceling the request. If
the request takes longer than this, your callback will be invoked
with an error whose name is "Timeout" .
|
errorOn404 |
A boolean specifying whether a 404 response should be treated as an
error or not. Defaults to true .
|
header |
A method for getting and setting individual headers. This is simply
a convenience method for reading and manipulating the
headers dictionary that accounts for the
case-insensitivity of headers. For example:
req.header('Content-Type', 'text/html') sets a header
and req.header('Content-Type') returns its value.
|
abort |
A method for aborting the request. This will will result in your
callback being invoked. If an error was caused by an
abort() call, its name will be "Abort" .
|
The error object
In the event of an error, an error object will be passed as the first argument
to your callback. If the error is an HTTP error, it will have all of the
properties that a response object has (listed below), but will be a JS Error
object (which can be useful if relying on instanceof checks). It also has one
additional property—message
—which contains a description of the error.
The response object
The response object passed to your callback in the event of a successful request
has the following properties:
status | The numeric status code. |
text | The raw response text. |
body |
The processed response body. Depending on the content type of the
response and the plugins being used, this may be the same as
`response.text` (a string) or some other object (like a parsed JSON
object).
|
contentType | The content type of the response. |
headers | An object containing the parsed response headers. |
header |
A method for looking up the value of a specific header. This takes
into account the case-insensitivity of headers. For example,
res.header('content-type') will return the correct
value regardless of the actual capitalization.
|
isHttpError |
A boolean that specifies whether this object represents a
server-reported HTTP error. This may be false—even on error objects—in
the case of non-HTTP errors like XDomain failures or plugin errors.
|
request | An object representing the request. |
xhr | The XHR or XDomain object used to make the request. |
Plugins
httpplease supports plugins for changing how requests are made. Some plugins
are built in:
Name | Enabled by Default? | Description |
---|
jsonresponse | No |
Converts JSON responses into JS objects on
response.body .
|
jsonrequest | No |
Serializes regular JavaScript objects stored on
request.body and sets the Content-Type header to
"application/json".
|
json | No |
Combines the "jsonrequest" and "jsonresponse" plugins.
|
cleanurl | Yes |
Encodes unencoded characters in the request URL. Required by some
browsers if you're using non-ASCII characters.
|
oldiexdomain | No |
Enables cross domain requests in IE9 by (transparently) using the
XDomainRequest object when necessary.
|
oldieactivex | No |
For
super old versions of IE
that didn't define XMLHttpRequest, use an ActiveX object.
|
setprotocol | No |
Automatically set the protocol for protocol-relative URLs, allowing
them to be used in Node. Protocol-relative URLs are important and
should be preferred since some browsers don't allow cross-protocol
requests. This plugin can also optionally force an override of
protocols even when they're present in the URL so that you can be
sure you won't have cross-protocol request issues in browsers.
|
Plugins are enabled with the use
method:
var json = require('httpplease/plugins/json');
httpplease = httpplease.use(json);
Or, if you're using the standalone build:
<script src="httpplease.js" type="text/javascript"></script>
<script src="httppleaseplugins.js" type="text/javascript"></script>
var json = httppleaseplugins.json;
httpplease = httpplease.use(json);
Notice that use
returns a new httpplease instance. This is so that you can
create multiple instances, each with their own plugins:
var http = httpplease.use(json);
http
.use(oldiexdomain)
.get('http://example.com', function (err, res) { ... });
http.get('http://example.com', function (err, res) { ... });
httpplease.get('http://example.com', function (err, res) { ... });
You can use as many plugins as you want—either by passing multiple plugins to
use
or chaining calls:
var http = httpplease
.use(json, oldiexdomain, myPlugin)
.use(anotherPlugin);
In order to keep your builds as small as possible, most plugins aren't enabled
by default. (See the table above.) However, some small plugins are. If you
want to disable all plugins, use the bare()
method:
var http = httpplease.bare();
Like use()
, this method also returns a new httpplease instance so you can
continue to use the old object with the original plugins intact.
Custom Plugins
In addition to the bundled plugins, you can create your own. Plugins are simply
objects that implement one or more of the following methods:
Method | Description |
---|
createXHR(req) |
Creates an XHR object. The first plugin that return a non-null value
from this method will be used.
|
processRequest(req) |
This method gives the plugin a chance to manipulate the request
object before the request is made. For example, it can change the
body or add headers.
|
processResponse(res) |
This method gives the plugin a chance to manipulate the response
object before the callback is invoked.
|
Similar Projects
Thanks
This project is mostly just a small wrapper around XMLHttpRequest and an (I
hope) sensible structure for extending functionality. The reason it works on the
server is because of driverdan's awesome node-XMLHttpRequest library—it's
the secret sauce that makes the browser-focused design of httpplease possible!
Changelog
I try to write good commit messages so the commit log should be very readable,
but here's a summary of some notable changes.
- v0.16.0
- Use
onload
on onerror
where available since onreadystatechange
can't
differentiate between 0 status code errors and successes
(matthewwithanm/react-inlinesvg#10)
- v0.15.0
- Rename "jsonparser" to "jsonresponse"
- Set Accept header in "jsonresponse" instead of "jsonrequest"
- Add "json" plugin that combines "jsonrequest" and "jsonresponse"
- v0.14.0
- Move plugins from
httpplease/lib/plugins
to httpplease/plugins
- v0.13.1
- Don't add Content-Type header if request has no body in jsonrequest
plugin. (This avoids an unneeded preflight request.)
- v0.13.0
- v0.12.0
- Add
abort
to request object
- v0.11.0
- v0.9.0
- Ignore request headers when using oldiexdomain
- Change when plugin methods are called
- v0.8.1
- Add Accept header if not present for jsonrequest
- v0.8.0
- v0.7.0
- v0.6.0
- Add jsonrequest plugin
- Add
header()
to Request and Response objects - More tests
- v0.5.3
- Improve content-type matching
- v0.5.1
- Fix bug with non-404s being suppressed by
errorOn404
- v0.5.0
- Return request object from http methods
- v0.4.0
- Added
errorOn404
option - Make
defaults
a method - Make
plugins
a method
- v0.3.0
- Response-like errors
- More tests
- v0.2.0
- Initial release as "httpplease"