Angular Websocket

Status: Looking for feedback about new API changes

An AngularJS 1.x WebSocket service for connecting client applications to servers.

How do I add this to my project?

You can download angular-websocket by:

• (prefered) Using bower and running bower install angular-websocket --save
• Using npm and running npm install angular-websocket --save
• Downloading it manually by clicking here to download development unminified version
• CDN for development https://cdn.rawgit.com/AngularClass/angular-websocket/v2.0.0/dist/angular-websocket.js
• CDN for production https://cdn.rawgit.com/AngularClass/angular-websocket/v2.0.0/dist/angular-websocket.min.js

Usage

  <script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.3.15/angular.min.js"></script>
  <script src="bower_components/angular-websocket/angular-websocket.js"></script>
  <section ng-controller="SomeController">
    <ul ng-repeat="data in MyData.collection track by $index" >
      <li> {{ data }} </li>
    </ul>
  </section>
  <script>
    angular.module('YOUR_APP', [
      'ngWebSocket' // you may also use 'angular-websocket' if you prefer
    ])
    //                          WebSocket works as well
    .factory('MyData', function($websocket) {
      // Open a WebSocket connection
      var dataStream = $websocket('ws://website.com/data');

      var collection = [];

      dataStream.onMessage(function(message) {
        collection.push(JSON.parse(message.data));
      });

      var methods = {
        collection: collection,
        get: function() {
          dataStream.send(JSON.stringify({ action: 'get' }));
        }
      };

      return methods;
    })
    .controller('SomeController', function ($scope, MyData) {
      $scope.MyData = MyData;
    });
  </script>

API

Factory: $websocket (in module ngWebSocket)

returns instance of $Websocket

Methods

name	arguments	description
$websocket constructor	url:String	Creates and opens a WebSocket instance. var ws = $websocket('ws://foo');
send	data:String,Object returns	Adds data to a queue, and attempts to send if socket is ready. Accepts string or object, and will stringify objects before sending to socket.
onMessage	callback:Function options{filter:String,RegExp, autoApply:Boolean=true}	Register a callback to be fired on every message received from the websocket, or optionally just when the message’s data property matches the filter provided in the options object. Each message handled will safely call $rootScope.$digest() unless autoApply is set to `false in the options. Callback gets called with a MessageEvent object.
onOpen	callback:Function	Function to be executed each time a socket connection is opened for this instance.
onClose	callback:Function	Function to be executed each time a socket connection is closed for this instance.
onError	callback:Function	Function to be executed each time a socket connection has an Error for this instance.
close	force:Boolean:optional	Close the underlying socket, as long as no data is still being sent from the client. Optionally force close, even if data is still being sent, by passing true as the force parameter. To check if data is being sent, read the value of socket.bufferedAmount.

Properties

name	type	description
socket	window.WebSocket	WebSocket instance.
sendQueue	Array	Queue of send calls to be made on socket when socket is able to receive data. List is populated by calls to the send method, but this array can be spliced if data needs to be manually removed before it’s been sent to a socket. Data is removed from the array after it’s been sent to the socket.
onOpenCallbacks	Array	List of callbacks to be executed when the socket is opened, initially or on re-connection after broken connection. Callbacks should be added to this list through the onOpen method.
onMessageCallbacks	Array	List of callbacks to be executed when a message is received from the socket. Callbacks should be added via the onMessage method.
onErrorCallbacks	Array	List of callbacks to be executed when an error is received from the socket. Callbacks should be added via the onError method.
onCloseCallbacks	Array	List of callbacks to be executed when the socket is closed. Callbacks should be added via the onClose method.
readyState	Number:readonly	Returns either the readyState value from the underlying WebSocket instance, or a proprietary value representing the internal state of the lib, e.g. if the lib is in a state of re-connecting.
initialTimeout	Number	The initial timeout, should be set at the outer limits of expected response time for the service. For example, if your service responds in 1ms on average but in 10ms for 99% of requests, then set to 10ms.
maxTimeout	Number	Should be as low as possible to keep your customers happy, but high enough that the system can definitely handle requests from all clients at that sustained rate.

CancelablePromise

This type is returned from the send() instance method of $websocket, inherits from $q.defer().promise.

Methods

name	arguments	description
cancel		Alias to deferred.reject(), allows preventing an unsent message from being sent to socket for any arbitrary reason.
then	resolve:Function, reject:Function	Resolves when message has been passed to socket, presuming the socket has a readyState of 1. Rejects if the socket is hopelessly disconnected now or in the future (i.e. the library is no longer attempting to reconnect). All messages are immediately rejected when the library has determined that re-establishing a connection is unlikely.

Service: $websocketBackend (in module ngWebSocketMock)

Similar to httpBackend mock in
AngularJS’s ngMock module. You can use ngWebSocketMock to mock a websocket
server in order to test your applications:

    var $websocketBackend;

    beforeEach(angular.mock.module('ngWebSocket', 'ngWebSocketMock');

    beforeEach(inject(function (_$websocketBackend_) {
      $websocketBackend = _$websocketBackend_;

      $websocketBackend.mock();
      $websocketBackend.expectConnect('ws://localhost:8080/api');
      $websocketBackend.expectSend({data: JSON.stringify({test: true})});
    }));

Methods

name	arguments	description
flush		Executes all pending requests
expectConnect	url:String	Specify the url of an expected WebSocket connection
expectClose		Expect “close” to be called on the WebSocket
expectSend	msg:String	Expectation of send to be called, with required message
verifyNoOutstandingExpectation		Makes sure all expectations have been satisfied, should be called in afterEach
verifyNoOutstandingRequest		Makes sure no requests are pending, should be called in afterEach

Frequently asked questions

• Q.: What if the browser doesn’t support WebSockets?
• A.: This module will not help; it does not have a fallback story for browsers that do not support WebSockets. Please check your browser target support here and to include fallback support.

Development

$ npm install
$ bower install

Changelog

Changelog

Unit Tests

$ npm test Run karma in Chrome, Firefox, and Safari

Manual Tests

In the project root directory open index.html in the example folder or browserify example

Distribute

$ npm run dist Builds files with uglifyjs

Support, Questions, or Feedback

Contact us anytime for anything about this repo or Angular 2

• Slack: AngularClass
• Gitter: angularclass/angular-websocket
• Twitter: @AngularClass

TODO

• Allow JSON if object is sent
• Allow more control over $digest cycle per WebSocket instance
• Add Angular interceptors
• Add .on(event)
• Include more examples of patterns for realtime Angular apps
• Allow for optional configuration object in $websocket constructor
• Add W3C Websocket support
• Add socket.io support
• Add SockJS support
• Add Faye support
• Add PubNub support

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enjoy — AngularClass

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License

MIT