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/Ember.js

Ember.Engine Class

PUBLIC

Extends: Ember.Namespace

Uses: RegistryProxy

Defined in: packages/ember-application/lib/system/engine.js:34

Module: ember-application

The Engine class contains core functionality for both applications and engines.

Each engine manages a registry that's used for dependency injection and exposed through RegistryProxy.

Engines also manage initializers and instance initializers.

Engines can spawn EngineInstance instances via buildInstance().

buildInstanceEmber.EngineInstanceprivate

Defined in packages/ember-application/lib/system/engine.js:79

Create an EngineInstance for this engine.

Returns:

Ember.EngineInstance
the engine instance

buildRegistry (namespace) Ember.Registryprivatestatic

Inherited from Ember.Engine but overwritten in packages/ember-application/lib/system/engine.js:359

This creates a registry with the default Ember naming conventions.

It also configures the registry:

  • registered views are created every time they are looked up (they are not singletons)
  • registered templates are not factories; the registered value is returned directly.
  • the router receives the application as its namespace property
  • all controllers receive the router as their target and controllers properties
  • all controllers receive the application as their namespace property
  • the application view receives the application controller as its controller property
  • the application view receives the application template as its defaultTemplate property

Parameters:

namespace Ember.Application
the application for which to build the registry

Returns:

Ember.Registry
the built registry

ensureInitializersprivate

Defined in packages/ember-application/lib/system/engine.js:66

Ensure that initializers are run once, and only once, per engine.

initializer (initializer) public

Inherited from Ember.Engine but overwritten in packages/ember-application/lib/system/engine.js:174

The goal of initializers should be to register dependencies and injections. This phase runs once. Because these initializers may load code, they are allowed to defer application readiness and advance it. If you need to access the container or store you should use an InstanceInitializer that will be run after all initializers and therefore after all code is loaded and the app is ready.

Initializer receives an object which has the following attributes: name, before, after, initialize. The only required attribute is initialize, all others are optional.

  • name allows you to specify under which name the initializer is registered. This must be a unique name, as trying to register two initializers with the same name will result in an error.
Ember.Application.initializer({
  name: 'namedInitializer',

  initialize: function(application) {
    Ember.debug('Running namedInitializer!');
  }
});
  • before and after are used to ensure that this initializer is ran prior or after the one identified by the value. This value can be a single string or an array of strings, referencing the name of other initializers.

An example of ordering initializers, we create an initializer named first:

Ember.Application.initializer({
  name: 'first',

  initialize: function(application) {
    Ember.debug('First initializer!');
  }
});

// DEBUG: First initializer!

We add another initializer named second, specifying that it should run after the initializer named first:

Ember.Application.initializer({
  name: 'second',
  after: 'first',

  initialize: function(application) {
    Ember.debug('Second initializer!');
  }
});

// DEBUG: First initializer!
// DEBUG: Second initializer!

Afterwards we add a further initializer named pre, this time specifying that it should run before the initializer named first:

Ember.Application.initializer({
  name: 'pre',
  before: 'first',

  initialize: function(application) {
    Ember.debug('Pre initializer!');
  }
});

// DEBUG: Pre initializer!
// DEBUG: First initializer!
// DEBUG: Second initializer!

Finally we add an initializer named post, specifying it should run after both the first and the second initializers:

Ember.Application.initializer({
  name: 'post',
  after: ['first', 'second'],

  initialize: function(application) {
    Ember.debug('Post initializer!');
  }
});

// DEBUG: Pre initializer!
// DEBUG: First initializer!
// DEBUG: Second initializer!
// DEBUG: Post initializer!
  • initialize is a callback function that receives one argument, application, on which you can operate.

Example of using application to register an adapter:

Ember.Application.initializer({
  name: 'api-adapter',

  initialize: function(application) {
    application.register('api-adapter:main', ApiAdapter);
  }
});

Parameters:

initializer Object

instanceInitializer (instanceInitializer) public

Inherited from Ember.Engine but overwritten in packages/ember-application/lib/system/engine.js:294

Instance initializers run after all initializers have run. Because instance initializers run after the app is fully set up. We have access to the store, container, and other items. However, these initializers run after code has loaded and are not allowed to defer readiness.

Instance initializer receives an object which has the following attributes: name, before, after, initialize. The only required attribute is initialize, all others are optional.

  • name allows you to specify under which name the instanceInitializer is registered. This must be a unique name, as trying to register two instanceInitializer with the same name will result in an error.
Ember.Application.instanceInitializer({
  name: 'namedinstanceInitializer',

  initialize: function(application) {
    Ember.debug('Running namedInitializer!');
  }
});
  • before and after are used to ensure that this initializer is ran prior or after the one identified by the value. This value can be a single string or an array of strings, referencing the name of other initializers.

  • See Ember.Application.initializer for discussion on the usage of before and after.

Example instanceInitializer to preload data into the store.

Ember.Application.initializer({
  name: 'preload-data',

  initialize: function(application) {
    var userConfig, userConfigEncoded, store;
    // We have a HTML escaped JSON representation of the user's basic
    // configuration generated server side and stored in the DOM of the main
    // index.html file. This allows the app to have access to a set of data
    // without making any additional remote calls. Good for basic data that is
    // needed for immediate rendering of the page. Keep in mind, this data,
    // like all local models and data can be manipulated by the user, so it
    // should not be relied upon for security or authorization.
    //
    // Grab the encoded data from the meta tag
    userConfigEncoded = Ember.$('head meta[name=app-user-config]').attr('content');
    // Unescape the text, then parse the resulting JSON into a real object
    userConfig = JSON.parse(unescape(userConfigEncoded));
    // Lookup the store
    store = application.lookup('service:store');
    // Push the encoded JSON into the store
    store.pushPayload(userConfig);
  }
});

Parameters:

instanceInitializer

resolverFor (namespace) *private

Defined in packages/ember-application/lib/system/engine.js:418

This function defines the default lookup rules for container lookups:

  • templates are looked up on Ember.TEMPLATES
  • other names are looked up on the application after classifying the name. For example, controller:post looks up App.PostController by default.
  • if the default lookup fails, look for registered classes on the container

This allows the application to register default injections in the container that could be overridden by the normal naming convention.

Parameters:

namespace Ember.Namespace
the namespace to look for classes

Returns:

*
the resolved value for a given lookup

runInitializersprivate

Defined in packages/ember-application/lib/system/engine.js:121

runInstanceInitializersprivate

Defined in packages/ember-application/lib/system/engine.js:143
Available since 1.12.0

_initializersRanprivate

Defined in packages/ember-application/lib/system/engine.js:58

A private flag indicating whether an engine's initializers have run yet.

resolverpublic

Inherited from Ember.Engine but overwritten in packages/ember-application/lib/system/engine.js:409

Set this to provide an alternate class to Ember.DefaultResolver

© 2017 Yehuda Katz, Tom Dale and Ember.js contributors
Licensed under the MIT License.
http://emberjs.com/api/classes/Ember.Engine.html