如何以及何时使用 Ember.Application 注册和注入方法? [英] How and when to use Ember.Application register and inject methods?

问题描述

我正在尝试了解如何使用 Ember.Application 注册 &注入方法

I'm trying to understand how to use Ember.Application register & inject methods

这些功能是为什么用例设计的?如何使用以及何时使用?

我真的很想知道！

推荐答案

默认情况下，Ember 在使用大多数约定启动应用程序时会进行依赖注入，例如，如果您使用 ember-data，则使用 store 类被注入到应用程序中的每个 route 和 controller 中，因此您稍后可以通过简单地执行 this.get('store') 来获取引用 在任何路由或控制器中.

Ember by default does dependency injection when it boots your application using mostly conventions, for example if you use ember-data then an instance of the store class is injected in every route and controller in your application, so you can later get a reference by simply doing this.get('store') inside any route or controller.

例如，这里是一个代码摘录，其中注册了默认的 store(取自 源)

For example here is a code extract where the default store get's registered (taken from the source)

Ember.onLoad('Ember.Application', function(Application) {
  Application.initializer({
    name: "store",

    initialize: function(container, application) {
      application.register('store:main', application.Store);
      ...
    }

    container.lookup('store:main');
  }
});

然后注入(来源)

Application.initializer({
  name: "injectStore",

  initialize: function(container, application) {
    application.inject('controller', 'store', 'store:main');
    application.inject('route', 'store', 'store:main');
    application.inject('dataAdapter', 'store', 'store:main');
  }
  ...
});

换句话说，register 和 inject 是注册依赖项并自己注入它们的方法.

In other words register and inject are methods to register dependencies and inject them yourself.

假设您有一个 Session 对象，您在应用程序启动时收到服务器请求后填充该对象，并且您希望在每个控制器中引用该对象，您可以执行以下操作:

Let's assume you have a Session object which you populate after a server request on application start, and which you want to have a reference to in every controller, you could do something like this:

var App = Ember.Application.create({
  ready: function(){
    this.register('session:current', App.Session, {singleton: true});
    this.inject('controller', 'session', 'session:current');
  }
});

App.Session = Ember.Object.extend({
  sessionHash: ''
});

此代码会将每个控制器实例的 session 属性设置为 App.Session 的单例实例，因此您可以在任何控制器中执行 this.get('session') 并获得对它的引用，因为它被定义为单例，所以它总是相同的 session 对象.

This code would set the session property of every controller instance to a singleton instance of App.Session, so you could in any controller do this.get('session') and get a reference to it, and since it's defined as a singleton it would be always the same session object.

使用register，您可以注册控制器、模型、视图或任何任意对象类型.inject，另一方面，可以注入给定类的所有实例.例如 inject('model', 'session', 'session:current') 也将使用 session:current 注入 session 属性实例到所有模型中.要注入 session 对象，假设您可以在 IndexView 上执行 inject('view:index', 'session', 'session:current').

With register you can register controllers, models, views, or any arbitrary object type. inject, in the other hand, can inject onto all instances of a given class. For example inject('model', 'session', 'session:current') would also inject the session property with the session:current instance into all models. To inject the session object, let's say onto the IndexView you could do inject('view:index', 'session', 'session:current').

尽管 register 和 inject 非常强大，但您应该明智地使用它们，并且只有在您确实知道没有其他方法可以实现目标的情况下，我猜缺乏文档表明气馁.

Although register and inject are very powerful you should use them wisely and only in the case you really know there is no other way to achieve your goal, I guess the lack of documentation is an indicator for discouragement.

因为提供一个工作示例和解释是必须的，所以它是:http://jsbin.com/usaluc/6/edit.请注意，在示例中，我们可以通过在我们所在的每个路由中使用 {{controller.session.sessionHash}} 引用当前控制器的会话对象来简单地访问提到的 sessionHash，这就是我们通过在应用程序的每个控制器中注册和注入 App.Session 对象所做的工作的优点.

Since It's mostly a must to provide a working example with an explanation, there it goes: http://jsbin.com/usaluc/6/edit. Notice how in the example we can simply access the mentioned sessionHash by referring to the current controller's session object with {{controller.session.sessionHash}} in every route we are in, this is the merit of what we have done by registering and injecting the App.Session object in every controller in the application.

希望有帮助.

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