Angularjs model changes after websocket data push

2019-02-13 06:46发布

问题:

I'm trying to change my angular model after a websocket push from the server. How is it possible to change values like $scope.contacts each time the server serves new data..?

I'm not sure if it is possible by using $apply. I know that I can access the DOM element retrieve the scope and then change the values, but there should be a better solution!

I'm really interested in a solution to update the angular model from outside without creating angular modules since I'm using relative data sources that emit change events. Is there no simple way to do that like in Backbone.js where you can say:

var book = new Backbone.Model({ title: 'value' });
book.set("title", "A Scandal in Bohemia");

What I want in angularjs is something like:

function MyController($scope) {
    $scope.contacts = [];
}

datasource changed -> function () {
    MyController.set('contacts', 'value'); // change angular scope property
}

回答1:

Look at socket.io angular service:

angular.module('app')
  .factory('socket', ['$rootScope', function ($rootScope) {

    var socket = io.connect();

    return {
      on: function (eventName, callback) {
        socket.on(eventName, function () {  
          var args = arguments;
          $rootScope.$apply(function () {
            callback.apply(socket, args);
          });
        });
      },
      emit: function (eventName, data, callback) {
        socket.emit(eventName, data, function () {
          var args = arguments;
          $rootScope.$apply(function () {
            if (callback) {
              callback.apply(socket, args);
            }
          });
        })
      }
    };

  }]);

and controller using it:

angular.module('app')
  .controller('Controller', ['$scope', 'socket', function ($scope, socket) {

    socket.emit('register')

    socket.on('register', function (data) {
        $scope.data = data;
    });

}]);


回答2:

just do it like below

 socket.onmessage = function (event) {
     scope.$apply(function(){
       // modify scope values here 
     }
    };


回答3:

Well, the marked answer is certainly not a "simple way" as requested by OP. Here's a much simpler solution.

Retrieve the scope wherever you want in your own JavaScript code:

var scope = angular.element($("#elementID")).scope();

Change a value in your Angular $scope variable, but from your external JavaScript:

scope.$apply(function() {
    scope.yourArrayForExample.push({name: 'New, external value'});
});

Here's a JSFiddle.