Ember.js current_user - 从控制器访问全局变量 [英] Ember.js current_user - accessing global variable from controller

问题描述

我对一个看似简单的余烬问题感到困惑.我正在使用 active_model_serializers 元数据序列化 从 rails 控制器序列化我的 rails current_user 方法，然后使用 这个人的临时解决方案.

I am baffled by a seemingly simple ember question. I am using active_model_serializers meta data serialization to serialize my rails current_user method from a rails controller, then extracting and setting that current_user meta json to a global ember variable using this guy's temporary solution.

App.CustomRESTSerializer = DS.RESTSerializer.extend({
  extractMeta: function(loader, type, json) {
    var meta;
    meta = json[this.configOption(type, 'meta')];
    if (!meta) { return; }
    Ember.set('App.metaData', meta);
    this._super(loader, type, json);
  }
});

到目前为止一切都很好.现在我可以通过输入 App.metaData.current_user 从控制台访问 current_user 信息，也可以通过调用特定属性从把手访问 current_user 信息，即:

All good up until this point. Now I can access the current_user information from the console by typing in App.metaData.current_user and also from handlebars by calling a specific attribute, i.e.:

{{App.metaData.current_user.email}}

并且该电子邮件属性显示在模板中.当我尝试从 ember 控制器中访问该全局变量时，问题就出现了.这看起来非常简单，但我似乎无法从任何 ember 控制器中访问 c​​urrent_user.我试过了:

and that email attribute shows up in the template. The problem comes when I am trying to access that global variable from within an ember controller. It seems so ridiculously easy, but I can't seem to access current_user from within any ember controller. I have tried:

currentUserBinding: 'App.metaData.current_user',

currentUser: function() {
  return App.metaData.current_user;
}.property(),

Ember.get('App.metaData.current_user')

和其他一些方法，但似乎无法访问它.奇怪的是，我可以通过直接路径从控制台和把手中如此轻松地访问 current_user，但不能从 ember 控制器中访问.我一定遗漏了一些明显的东西.

and a few other methods, but can't seem to access it. It's bizarre that I can access current_user so easily from within the console and handlebars with a direct path, but not from within an ember controller. I must be missing something obvious.

非常感谢您的帮助！

推荐答案

在我们的应用程序中，我们按照@MilkyWayJoe 的建议进行操作，但我认为您的方法非常有趣.通过 JSON 传递 current_user 是一种非常优雅的方法.

In our app we do it same as @MilkyWayJoe suggested, but I think your approach is really interesting. Passing current_user thru JSON is a really elegant approach.

我没有做过太多实验，但是从我在您的示例中可以看出，问题与序列化程序无关.这是计算属性的问题 - 您需要指定它依赖于 App.metaData.current_user.

I've not experimented too much, but from what I can tell in your example the problem is nothing to do with the serializer. It's a problem with the computed property - you need to specify that it depends on App.metaData.current_user.

App.ApplicationController = Ember.Controller.extend({
  currentUser: function() {
    return Ember.get('App.metaData.current_user')
  }.property('App.metaData.current_user')
});

这告诉 ember 它应该在 App.metaData.currentUser 更改时重新计算 currentUser 属性.否则它将运行一次 fx(在您的 ajax 返回之前)并缓存响应.

This tells ember that it should re-calculate the currentUser property whenever App.metaData.currentUser changes. Otherwise it will run the fx once (before your ajax returns) and cache the response.

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