Model.find（）。then（）在实际加载记录之前触发 [英] Model.find().then() fires before records are actually loaded

问题描述

我想加载一个完整的集合，然后只是剥离记录，以便一次使用一个模型，而不必每次都向服务器往返。

I would like to load an entire collection and then just peel off records to use as models one at a time, without doing a roundtrip to the server every time.

我已经弄清楚如何使用Ember.Deferred退回承诺，但是我无法在合适的时间得到承诺来解决。以下代码只是输出找到0：

I've figured out how to use Ember.Deferred to return a promise, but I can't get the promise to resolve at the right time. The following code just outputs "Found 0" ever time:

App.PersonRoute = Ember.Route.extend({
  model: function(params) {
    var name = "Erik";
    var promise = Ember.Deferred.create();
    App.people = App.Person.find();

    App.people.then(function() {
      console.log('Found ' + App.people.get('length'));
      var person = App.people.findProperty('name', name)
      promise.resolve(person);
    });

    return promise;
  }
});

如果我将then（）的正文包装在setTimeout中，并使其等待几秒钟，一切都很好。

If I wrap the body of the then() in a setTimeout, and make it wait a couple seconds, everything works great.

有没有另外一个可以以某种方式绑定的事件？我尝试过App.people.on（'isLoaded'），但是它是永远是真的。

Is there another event I can somehow bind to? I tried App.people.on('isLoaded'), but isLoaded is always true.

谢谢！

推荐答案

是否有另一个事件可以以某种方式绑定？

Is there another event I can somehow bind to?

确实有一个你可以听的事件，那就是 didLoad 。

Indeed there is an event you can listen to and that is didLoad.

我尝试过App.people.on（'isLoaded'），但是这个颜色总是为真。

I tried App.people.on('isLoaded'), but isLoaded is always true.

至于 isLoaded 对此有很多困惑，请参见此处，混淆来自于当商店已经完成加载 RecordArray时，设计将 isLoaded 标志设置为true ，即使最初空，因为没有可用的本地记录。然后当对服务器的请求返回时，将从后端收到的记录填充 RecordArray ，绑定将开始，您的模板更新。

As for isLoaded there was a lot of confusion about this, see here for example, the confusion comes from the fact that the isLoaded flag is set to true by design when the store has finished loading the RecordArray for the records, even when initially empty because no record was already available locally. Then when the request to the server comes back the RecordArray will be populated with the records received from the backend, and bindings will kick off and your templates are updated.

如指南所述：

既加载又清洁的记录意味着已经从服务器接收到有关其属性和关系的信息，并且在客户端上本地没有进行任何更改。

A record that is both loaded and clean means that is has received information about its attributes and relationships from the server, and no changes have been made locally on the client.

以上所述是什么使得 didLoad fire。

Was is stated above is what makes didLoad fire.

有关更多的模型相关事件，您可以在下查看指南模型生命周期

For more model related events you can listen to have a look at the guides under model lifecycle

现在，您可以将代码重写为您的设置：

Now to your setup, you could rewrite your code to something like this:

App.PersonRoute = Ember.Route.extend({
  model: function(params) {
    var name = "Erik";
    var promise = Ember.Deferred.create();
    App.people = App.Person.find();

    App.people.on('didLoad', function() {
      console.log('Found ' + App.people.get('length'));
      var person = App.people.findProperty('name', name)
      promise.resolve(person);
    });

    return promise;
  }
});

希望有帮助。

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