Search code examples
javascriptangularjsevent-drivenevent-driven-design

What's the best practice to do event driven development in Angular.js apps?


I am adding some websocket functional to our angular app. The Websocket object is wrapped in a service. Ideally we would like our wrapped socket object to have a standard event API so that we can use it in the controller like the following: (Sorry for the Coffeescript)

angular.module('myApp').controller 'myCtrl', ($scope, socket) ->
  update = (msg)->
    $scope.apply ->
      #do something regarding to the msg

  socket.on 'message', update

  unregister: ->
    socket.off 'message', update  

What's the best practice/library for us to achieve this? Use jquery? Backbone.Events? Any suggestion will be helpful. Thanks!


Solution

  • You don't need to use any library to achieve this, just create a service, inject $rootscope and publish the events from there to rootscope, then in your controller listen for that event.

    var socket; // this be the socketio instance.
    angular.module("myApp").factory("SocketHandler", function ($rootScope) {
      var handler = function (msg) {
        $rootScope.$apply(function () {
          $rootScope.$broadcast("socketMessageReceived", msg);
        });
      };
    
      socket.on("message", handler);
    
      $rootScope.$on("unregisterSocket", function () {
        socket.off("message", handler);
      });
    }).controller("myCtrl", function ($scope, SocketHandler) {
      var listener;
      var addListener = function () {
        listener = $scope.$on("messageReceived", function (e, msg) {
          console.log("New Message: " + msg);
        }); // $on returns a registration function for the listener
      };
      var removeListener = function () {
        if (listener) listener();
      };
    });