EmberJS WebSockets Addon
This addon aims to be a simple and easy way to integrate with any websocket backend. It has been designed to be minimalistic, flexible, and lightweight instead of forcing certain conventions on the developer. This addon is compatible with EmberJS 2.0!
http://www.programwitherik.com/getting-started-with-web-sockets-and-ember/
Installation
To install as an Ember CLI addon (v0.2.3 or greater):
ember install ember-websockets
Simple example of using it in your app
import Ember from 'ember';
export default Ember.Controller.extend({
/*
* 1) First step you need to do is inject the websocket service into your object. You
* can inject the service into component, controllers, object, mixins, routes, and views.
*/
socketService: Ember.inject.service('websockets'),
init: function() {
this._super.apply(this, arguments);
/*
* 2) The next step you need to do is to create your actual websocket. Calling socketFor
* will retrieve a cached websocket if one exists or in this case it
* will create a new one for us.
*/
var socket = this.get('socketService').socketFor('ws://localhost:7000/');
/*
* 3) The final step is to define your event handlers. All event handlers
* are added via the `on` method and take 3 arguments: event name, callback
* function, and the context in which to invoke the callback. All 3 arguments
* are required.
*/
socket.on('open', this.myOpenHandler, this);
socket.on('message', this.myMessageHandler, this);
socket.on('close', function(event) {
// anonymous functions work as well
}, this);
},
myOpenHandler: function(event) {
console.log('On open event has been called: ' + event);
},
myMessageHandler: function(event) {
console.log('Message: ' + event.data);
},
actions: {
sendButtonPressed: function() {
/*
* If you need to retrieve your websocket from another function or method you can simply
* get the cached version at no penalty
*/
var socket = this.get('socketService').socketFor('ws://localhost:7000/');
socket.send('Hello Websocket World');
}
}
});Sending messages to the server
var socket = this.get('socketService').socketFor('ws://localhost:7000/');
socket.send('Hello Websocket World', true);The send method takes 2 arguments. A message which is passed into the native websockets send method and an optional stringify boolean. This boolean, if set to true, will do a JSON.stringify to the message before passing it to the websocket send method. If you are sending strings it is recommended to pass true.
Reconnecting
import Ember from 'ember';
export default Ember.Controller.extend({
socketService: Ember.inject.service('websockets'),
init: function() {
this._super.apply(this, arguments);
var socket = this.get('socketService').socketFor('ws://localhost:7000/');
socket.on('open', function(event) {
console.log('This will be called');
}, this);
socket.on('close', function(event) {
Ember.run.later(this, function() {
/*
* This will remove the old socket and try and connect to a new one on the same url.
* NOTE: that this does not need to be in a Ember.run.later this is just an example on
* how to reconnect every second.
*/
socket.reconnect();
}, 1000);
}, this);
}
});Closing the connection
import Ember from 'ember';
export default Ember.Controller.extend({
socketService: Ember.inject.service('websockets'),
/*
* To close a websocket connection simply call the closeSocketFor method. NOTE: it is good
* practice to close any connections after you are no longer in need of it. A good
* place for this clean up is in the willDestroy method of the object.
*/
willDestroy() {
this.get('socketService').closeSocketFor('ws://localhost:7000/');
}
});Multiple Websockets
import Ember from 'ember';
export default Ember.Controller.extend({
socketService: Ember.inject.service('websockets'),
init: function() {
this._super.apply(this, arguments);
var socketOne = this.get('socketService').socketFor('ws://localhost:7000/');
var socketTwo = this.get('socketService').socketFor('ws://localhost:7001/');
socketOne.on('open', function(event) {
console.log('Hello from socket one');
}, this);
socketTwo.on('open', function(event) {
console.log('Hello from socket two');
}, this);
}
});Multiple Event Handlers
import Ember from 'ember';
export default Ember.Controller.extend({
socketService: Ember.inject.service('websockets'),
init: function() {
this._super.apply(this, arguments);
var socket = this.get('socketService').socketFor('ws://localhost:7000/');
socket.on('open', function(event) {
console.log('This will be called');
}, this);
socket.on('open', function(event) {
console.log('This will also be called');
}, this);
}
});Detailed explanations of the APIs
SocketFor
Example:
var socket = this.get('socketService').socketFor('ws://localhost:7000/');socketFor takes a single argument, a url, and returns a socket instance from its cache or a new websocket connection if one was not found.
On
Example:
var socket = this.get('socketService').socketFor('ws://localhost:7000/');
socket.on('open', this.myOpenFunction, this);on takes 3 arguments: event type, callback function, and context. Event type can be one of the following: 'open', 'message', 'close', and 'error'. Callback function will be invoked when one of the previous event types occurs. Context is used to set the context of the callback function and also to remove the listeners when the context gets destroyed.
Off
Example:
var socket = this.get('socketService').socketFor('ws://localhost:7000/');
socket.on('open', this.myOpenFunction, this);
socket.off('open', this.myOpenFunction);off takes 3 arguments: event type, callback function. Event type can be one of the following: 'open', 'message', 'close', and 'error'. The callback will be removed from the event pool and will no longer be invoked.
CloseSocketFor
Example:
var socket = this.get('socketService').socketFor('ws://localhost:7000/');
this.get('socketService').closeSocketFor('ws://localhost:7000/');closeSocketFor takes a single argument, a url, and closes the websocket connection. It will also remove it from the cache. In normal cases you would not have to call this method.
Reconnect
Example:
socket.on('close', function(event) {
socket.reconnect();
});reconnect takes no arguments. It will attempt to create a new websocket connect using the previous url.
If the connect is not successful the close event will be triggered.
Deprecations
Before v1.0.0 there was a websocket mixin that you would add to your router and you would define your event handlers via actions on the controller. If you still need the documentation for this approach it is here.
Live Example
git clone git@github.com:thoov/ember-websockets.gitcd ember-websocketsnpm installember s- Then visit http://localhost:4200/sockets/chatroom to view a very simple example.
The source code for the live example lives in ember-websockets/tests/dummy
Running tests
git clone git@github.com:thoov/ember-websockets.gitcd ember-websocketsnpm installember t- or
ember sthen visit http://localhost:4200/tests to view the tests.
NOTE: To get the test to run in PhantomJS I created a mocking library found here: mocking library Note that it is still a work in progress.
Feedback or issues
If you have any feedback, encounter any bugs, or just have a question, please feel free to create a github issue or send me a tweet at @thoov.
FAQ
-
Recommended backend library/framework: The only requirement for this mixin to work is a service that can handle ws or wss protocols. For this reason socket.io will not work as it does not use the standard ws protocol. Instead, I would look at ws which is a great package.
-
Browser Support: Current support for browsers is fairly good with all modern browsers and most mobile browsers supporting websockets in their current and previously stable versions. It goes without saying that older versions of IE are not supported. For a more detailed break down
-
License: This addon falls under the MIT license