AngularJS工厂财产不被在$范围不使用时推（更新） [英] AngularJS factory property isn't being updated in $scope when not using push()

问题描述

我有一个工厂，从外部源检索数据。当我得到的数据，我用第二工厂通过一定的标准对其进行过滤。

I have a factory that is retrieving the data from an external source. As soon as i get the data, i use a second factory to filter it by a certain criteria.

工厂属性分配范围。

现在当我做这在我的工厂，它不更新的范围：

Now when i do this in my factory, it doesn't update the scope:

factory.foo = [{id:1,name:'foo'}]; // doesn't work

也为此在第二工厂filterin不起作用

therefor also the filterin in a second factory doesn't work

factory.foo = Filter.filter(); // doesn't work

而这个作品：

factory.foo.push({id:1,name:'foo'}); // works

没有任何人有一个想法，如果这样做的目的，为什么它是这样的，如何解决它？

Does anyone have an idea if this is intended and why it is like this, and how to solve it?

全样本加上plunkr

app.factory('Foo',function(Filter) {
  var factory = {
    foo:[],
    getDataForFoo:function() {
      factory.foo = Filter.filter(); // doesn't work
      //factory.foo = [{id:1,name:'foo'},{id:1,name:'foo'}]; // doesn't work
      //factory.foo.push({id:1,name:'foo'}); // works
    }
  };
  return factory;
});

app.factory('Filter',function() {
  var factory = {
    filter:function() {
      var arr = [];
      arr.push({id:1,name:'foo'});
      return arr;
    }
  }
  return factory;
});

app.controller('MainCtrl', function($scope,Foo) {
  $scope.test = 'running';
  $scope.foo = Foo.foo;

  $scope.click = Foo.getDataForFoo;
});

Plunkr

推荐答案

的问题是，你的工厂替换参考 Factory.foo 。当你的范围被初始化， $ scope.foo 保存到一个数组（空）的引用。当你调用 Foo.getDataForFoo ，它在内部改变参照 Factory.foo 但是你的范围仍然坚持参考在previous阵列。这就是为什么使用推工作，它不会改变数组引用，但数组的内容。

The problem is that your factory replace the reference to Factory.foo. When your scope is initialized, $scope.foo holds a reference to an array (empty). When you call Foo.getDataForFoo, it internally changes the reference to Factory.foo but your scope still hold a reference to the previous array. This is why using push works as it doesn't change the array reference, but the array content.

有几种方法来解决这个问题。如果没有所有不同的选择去，最简单的一种是包装你的 $ scope.foo 在一个函数，返回 Factory.foo 。通过这种方式，将角检测摘要周期参考的变化并相应地更新视图。

There are a few ways to fix this. Without going in all the different options, the easiest one is to wrap your $scope.foo in a function, returning Factory.foo. This way, Angular will detect a reference change in a digest cycle and will update the view accordingly.

app.controller('MainCtrl', function($scope,Foo) {
  $scope.test = 'running';
  $scope.foo = function() { return Foo.foo };

  $scope.click = Foo.getDataForFoo
});

// And in the view (the relevant part)

<ul ng-repeat="elem in foo()">
  <li>{{elem.id}} {{elem.name}}</li>
</ul>
<a href="" ng-click="click()">add</a>

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