Engine
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.EngineInstance
private
Create an EngineInstance for this engine.
Returns:
-
Ember.EngineInstance
- the engine instance
buildRegistry (namespace) Ember.Registry
privatestatic
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
andcontrollers
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
Ensure that initializers are run once, and only once, per engine.
initializer (initializer) public
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
andafter
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 thename
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
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
andafter
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 thename
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
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 upApp.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
runInstanceInitializersprivate
_initializersRanprivate
A private flag indicating whether an engine's initializers have run yet.
resolverpublic
Set this to provide an alternate class to Ember.DefaultResolver
© 2017 Yehuda Katz, Tom Dale and Ember.js contributors
Licensed under the MIT License.
https://emberjs.com/api/classes/Ember.Engine.html