EmberJS WebSockets Addon

This addon aims to be a simple and easy way to integrate with any websocket or socket.io backend. It has been designed to be minimalistic, flexible, and lightweight instead of forcing certain conventions on the developer.

http://www.programwitherik.com/getting-started-with-web-sockets-and-ember/

Installation

ember install ember-websockets

Simple example of using it in your app

import Ember from 'ember';

export default Ember.Component.extend({

  /*
  * 1) First step you need to do is inject the websocket service into your object.
  */
  socketService: Ember.inject.service('websockets'),
  socketRef: null,

  willRender() {
    /*
    * 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.
    */
    const socket = this.get('socketService').socketFor('ws://localhost:7000/');

    /*
    * 3) The next 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', this.myCloseHandler, this);
    
    this.set('socketRef', socket);
  },

  willDestroyElement() {
    const socket = this.get('socketRef');

    /*
    * 4) The final step is to remove all of the listeners you have setup.
    */
    socket.off('open', this.myOpenHandler);
    socket.off('message', this.myMessageHandler);
    socket.off('close', this.myCloseHandler);
  },

  myOpenHandler(event) {
    console.log(`On open event has been called: ${event}`);
  },

  myMessageHandler(event) {
    console.log(`Message: ${event.data}`);
  },

  myCloseHandler(event) {
    console.log(`On close event has been called: ${event}`);
  },

  actions: {
    sendButtonPressed() {
      const socket = this.get('socketRef');
      socket.send('Hello Websocket World');
    }
  }
});

Sending messages to the server

var socket = this.get('socketService').socketFor('ws://localhost:7000/');
socket.send({username: 'foo', didSomeAction: 'pressedAButton'}, true);

// the above line is the same as this:
socket.send(JSON.stringify({username: 'foo', didSomeAction: 'pressedAButton'}));

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.Component.extend({
  socketService: Ember.inject.service('websockets'),

  willRender() {
    const socket = this.get('socketService').socketFor('ws://localhost:7000/');
    socket.on('close', this.myOnClose, this);
  },

  myOnClose() {
    const socket = this.get('socketService').socketFor('ws://localhost:7000/');
    Ember.run.later(this, () => {
      /*
      * 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);
  },

  willDestroyElement() {
    const socket = this.get('socketService').socketFor('ws://localhost:7000/');
    socket.off('close', this.myOnClose);
  }
});

Closing the connection

import Ember from 'ember';

export default Ember.Component.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 willDestroyElement method of the object.
  */
  willDestroyElement() {
    this.get('socketService').closeSocketFor('ws://localhost:7000/');
  }
});

Multiple Websockets

import Ember from 'ember';

export default Ember.Component.extend({
  socketService: Ember.inject.service('websockets'),

  willRender() {
    const socketOne = this.get('socketService').socketFor('ws://localhost:7000/');
    const socketTwo = this.get('socketService').socketFor('ws://localhost:7001/');

    socketOne.on('open', this.myOpenFirst, this);
    socketTwo.on('open', this.myOpenSeconds, this);
  },

  myOpenFirst(event) {
    console.log('Hello from socket one');
  },

  myOpenSecond(event) {
    console.log('Hello from socket two');
  },

  willDestroyElement() {
    const socket = this.get('socketService').socketFor('ws://localhost:7000/');
    const socketTwo = this.get('socketService').socketFor('ws://localhost:7001/');
    socketOne.off('open', this.myOpenFirst);
    socketTwo.off('open', this.myOpenSecond);
  }
});

Multiple Event Handlers

import Ember from 'ember';

export default Ember.Component.extend({
  socketService: Ember.inject.service('websockets'),

  willRender() {
    var socket = this.get('socketService').socketFor('ws://localhost:7000/');

    socket.on('open', this.myOpenFirst, this);
    socket.on('open', this.myOpenSecond, this);
  },

  myOpenFirst() {
    console.log('This will be called');
  },

  myOpenSecond() {
    console.log('This will also be called');
  },

  willDestroyElement() {
    const socket = this.get('socketService').socketFor('ws://localhost:7000/');
    socket.off('open', this.myOpenFirst);
    socket.off('open', this.myOpenSecond);
  }
});

Socket.IO Support

First run the socket.io generator via:

ember g socket-io

import Ember from 'ember';

export default Ember.Component.extend({

  /*
  * 1) First step you need to do is inject the socketio service into your object.
  */
  socketIOService: Ember.inject.service('socket-io'),

  willRender() {
    /*
    * 2) The next step you need to do is to create your actual socketIO.
    */
    const socket = this.get('socketIOService').socketFor('http://localhost:7000/');

    /*
    * 3) Define any event handlers
    */
    socket.on('connect', this.onConnect, this);
    socket.on('message', this.onMessage, this);

    /*
    * 4) It is also possible to set event handlers on specific events
    */
    socket.on('myCustomNamespace', () => { socket.emit('anotherNamespace', 'some data'); });
  },

  onConnect() {
    const socket = this.get('socketIOService').socketFor('http://localhost:7000/');

    /*
    * There are 2 ways to send messages to the server: send and emit
    */
    socket.send('Hello World');
    socket.emit('Hello server');
  },

  onMessage(data) {
    // This is executed within the ember run loop
  },

  myCustomNamespace(data) {
    const socket = this.get('socketIOService').socketFor('http://localhost:7000/');
    socket.emit('anotherNamespace', 'some data');
  },

  willDestroyElement() {
    const socket = this.get('socketService').socketFor('http://localhost:7000/');
    socket.off('connect', this.onConnect);
    socket.off('message', this.onMessage);
    socket.off('myCustomNamespace', this.myCustomNamespace);
  }
});

Please visit: socket.io docs for more details on ember-websocket + socket.io

Detailed explanations of the APIs

SocketFor

Example:

var socket = this.get('socketService').socketFor('ws://localhost:7000/', ['myOptionalProtocol']);

socketFor takes two arguments: a url, a protocol array (optional), 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.myOtherOpenFunction);

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 event types occurs.

Off

Example:

const socket = this.get('socketService').socketFor('ws://localhost:7000/');

let openFunctionReference = this.myOpenFunction.bind(this);

socket.on('open', openFunctionReference);
socket.off('open', openFunctionReference);

off takes 2 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:

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', 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.

Live Example

• git clone [email protected]:thoov/ember-websockets.git
• cd ember-websockets
• npm i; bower i
• ember 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 [email protected]:thoov/ember-websockets.git
• cd ember-websockets
• npm i; bower i
• ember t
• or ember s then 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

• ws
• socket.io

License

This addon falls under the MIT license