Restler

(C) Dan Webb (dan@danwebb.net/@danwrong) 2011, Licensed under the MIT-LICENSE

An HTTP client library for node.js (0.6.x and up). Hides most of the complexity of creating and using http.Client.

Release 2.x.x is dedicated to modifying how errors are handled and emitted. Currently errors are being fired as an on 'error' event but as @ctavan pointed out on issue #36 a better approach (and more commonly in vogue now) would be to pass the error obj to the callback.

Ths change will inevitably affect those using older < 0.2.x versions of restler. Those not ready to upgrade yet are encouraged to stay on the 0.2.x version.

See Version History for changes

Features

• Easy interface for common operations via http.request
• Automatic serialization of post data
• Automatic serialization of query string data
• Automatic deserialization of XML, JSON and YAML responses to JavaScript objects (if you have js-yaml and/or xml2js in the require path)
• Provide your own deserialization functions for other datatypes
• Automatic following of redirects
• Send files with multipart requests
• Transparently handle SSL (just specify https in the URL)
• Deals with basic auth for you, just provide username and password options
• Simple service wrapper that allows you to easily put together REST API libraries
• Transparently handle content-encoded responses (gzip, deflate) (requires node 0.6+)
• Transparently handle different content charsets via iconv (if available)

API

request(url, options)

Basic method to make a request of any type. The function returns a RestRequest object that emits events:

events

• complete: function(result, response) - emitted when the request has finished whether it was successful or not. Gets passed the response result and the response object as arguments. If some error has occurred, result is always instance of Error, otherwise it contains response data.
• success: function(data, response) - emitted when the request was successful. Gets passed the response data and the response object as arguments.
• fail: function(data, response) - emitted when the request was successful, but 4xx status code returned. Gets passed the response data and the response object as arguments.
• error: function(err, response) - emitted when some errors have occurred (eg. connection aborted, parse, encoding, decoding failed or some other unhandled errors). Gets passed the Error object and the response object (when available) as arguments.
• abort: function() - emitted when request.abort() is called.
• 2XX, 3XX, 4XX, 5XX: function(data, response) - emitted for all requests with response codes in the range (eg. 2XX emitted for 200, 201, 203).
• actual response code: function(data, response) - emitted for every single response code (eg. 404, 201, etc).

members

• abort([error]) Cancels request. abort event is emitted. request.aborted is set to true. If non-falsy error is passed, then error will be additionaly emitted (with error passed as a param and error.type is set to "abort"). Otherwise only complete event will raise.
• retry([timeout]) Re-sends request after timeout ms. Pending request is aborted.
• aborted Determines if request was aborted.

get(url, options)

Create a GET request.

post(url, options)

Create a POST request.

put(url, options)

Create a PUT request.

del(url, options)

Create a DELETE request.

head(url, options)

Create a HEAD request.

json(url, data, options)

Send json data via GET method.

postJson(url, data, options)

Send json data via POST method.

Parsers

You can give any of these to the parsers option to specify how the response data is deserialized. In case of malformed content, parsers emit error event. Original data returned by server is stored in response.raw.

parsers.auto

Checks the content-type and then uses parsers.xml, parsers.json or parsers.yaml. If the content type isn't recognised it just returns the data untouched.

parsers.json, parsers.xml, parsers.yaml

All of these attempt to turn the response into a JavaScript object. In order to use the YAML and XML parsers you must have yaml and/or xml2js installed.

Options

• method Request method, can be get, post, put, del. Defaults to "get".
• query Query string variables as a javascript object, will override the querystring in the URL. Defaults to empty.
• data The data to be added to the body of the request. Can be a string or any object. Note that if you want your request body to be JSON with the Content-Type: application/json, you need to JSON.stringify your object first. Otherwise, it will be sent as application/x-www-form-urlencoded and encoded accordingly. Also you can use json() and postJson() methods.
• parser A function that will be called on the returned data. Use any of predefined restler.parsers. See parsers section below. Defaults to restler.parsers.auto.
• encoding The encoding of the request body. Defaults to "utf8".
• decoding The encoding of the response body. For a list of supported values see Buffers. Additionally accepts "buffer" - returns response as Buffer. Defaults to "utf8".
• headers A hash of HTTP headers to be sent. Defaults to { 'Accept': '*/*', 'User-Agent': 'Restler for node.js' }.
• username Basic auth username. Defaults to empty.
• password Basic auth password. Defaults to empty.
• multipart If set the data passed will be formated as multipart/form-encoded. See multipart example below. Defaults to false.
• client A http.Client instance if you want to reuse or implement some kind of connection pooling. Defaults to empty.
• followRedirects If set will recursively follow redirects. Defaults to true.

Example usage

var sys = require('util'),
    rest = require('./restler');

rest.get('http://google.com').on('complete', function(result) {
  if (result instanceof Error) {
    sys.puts('Error: ' + result.message);
    this.retry(5000); // try again after 5 sec
  } else {
    sys.puts(result);
  }
});

rest.get('http://twaud.io/api/v1/users/danwrong.json').on('complete', function(data) {
  sys.puts(data[0].message); // auto convert to object
});

rest.get('http://twaud.io/api/v1/users/danwrong.xml').on('complete', function(data) {
  sys.puts(data[0].sounds[0].sound[0].message); // auto convert to object
});

rest.post('http://user:pass@service.com/action', {
  data: { id: 334 },
}).on('complete', function(data, response) {
  if (response.statusCode == 201) {
    // you can get at the raw response like this...
  }
});

// multipart request sending a 321567 byte long file using https
rest.post('https://twaud.io/api/v1/upload.json', {
  multipart: true,
  username: 'danwrong',
  password: 'wouldntyouliketoknow',
  data: {
    'sound[message]': 'hello from restler!',
    'sound[file]': rest.file('doug-e-fresh_the-show.mp3', null, 321567, null, 'audio/mpeg')
  }
}).on('complete', function(data) {
  sys.puts(data.audio_url);
});

// create a service constructor for very easy API wrappers a la HTTParty...
Twitter = rest.service(function(u, p) {
  this.defaults.username = u;
  this.defaults.password = p;
}, {
  baseURL: 'http://twitter.com'
}, {
  update: function(message) {
    return this.post('/statuses/update.json', { data: { status: message } });
  }
});

var client = new Twitter('danwrong', 'password');
client.update('Tweeting using a Restler service thingy').on('complete', function(data) {
  sys.p(data);
});

// post JSON
var jsonData = { id: 334 };
rest.postJson('http://example.com/action', jsonData).on('complete', function(data, response) {
  // handle response
});

Running the tests

install nodeunit

npm install nodeunit

then

node test/all.js

or

nodeunit test/restler.js

TODO

• What do you need? Let me know or fork.