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.
这篇关于观察非全局全局变量的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!