观察非全局全局变量 [英] Observe non-ember globals

问题描述

我想要一个计算属性来观察一个非空白全局：localStorage中的一个特定键。这可能吗？以下似乎没有被削减：

I want a computed property to observe a non-ember global: a specific key in localStorage. Is this possible? The following does not seem to cut it:

someProperty:function(){
    //some functionality
}.property('localStorage.someKey')

是否可以做我正在尝试直接做？

Is it possible to do what I'm trying to do directly?

推荐答案

一般来说，您可以观察一般的JavaScript对象。您只需要使用 Ember.get 和 Ember.set 来修改它们：

In general, you can observe regular JavaScript objects just fine. You just need to use Ember.get and Ember.set to modify them:

var pojo = {};

var MyObject = Ember.Object.extend({
  bigEyeballs: function() {
    var O_O = this.get('pojo.O_O');
    if (O_O) { return O_O.toUpperCase(); }
  }.property('pojo.O_O')
});

var obj = MyObject.create({ pojo: pojo });
console.log(obj.get('bigEyeballs'));

Ember.set(pojo, 'O_O', "wat");
console.log(obj.get('bigEyeballs'));

你可以看到这个工作在这个JSBin 。

You can see this working in this JSBin.

本地存储是一个不同的事情，因为它不是真正 JavaScript对象。您可以在本地存储区周围创建一个小型Ember包装，并用于观察：

Local Storage is a bit of a different matter, as it's not really a normal JavaScript object. You can create a small Ember wrapper around local storage, and use that for observation:

var LocalStorage = Ember.Object.extend({
  unknownProperty: function(key) {
    return localStorage[key];
  },

  setUnknownProperty: function(key, value) {
    localStorage[key] = value;
    this.notifyPropertyChange(key);
    return value;
  }
});

var storage = new LocalStorage();

var MyObject = Ember.Object.extend({
  bigEyeballs: function() {
    var O_O = this.get('pojo.O_O');
    if (O_O) { return O_O.toUpperCase(); }
  }.property('pojo.O_O')
});

var obj = MyObject.create({ pojo: storage });

console.log(obj.get('bigEyeballs'));

Ember.set(storage, 'O_O', "wat");
console.log(obj.get('bigEyeballs'));

您可以在 JSBin 。

在这两种情况下，重要的是您必须使用Ember感知设置并遵守这些属性。

In both cases, the important thing is that you will have to use Ember-aware setting and getting in order to observe these properties.

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