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  • Classes
    • Adapter
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    • EngineInstance
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Class EngineInstance public


Extends: EmberObject
Uses: RegistryProxyMixin , ContainerProxyMixin
Defined in: packages/ember-application/lib/system/engine-instance.js:17
Module: @ember/engine
import EngineInstance from '@ember/engine/instance';

The EngineInstance encapsulates all of the stateful aspects of a running Engine.


Methods

addObserver (key, target, method) : Ember.Observable public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:331

key
String

The key to observe

target
Object

The target object to invoke

method
String|Function

The method to invoke

returns
Ember.Observable

Adds an observer on a property.

This is the core method used to register an observer for a property.

Once you call this method, any time the key's value is set, your observer will be notified. Note that the observers are triggered any time the value is set, regardless of whether it has actually changed. Your observer should be prepared to handle that.

Observer Methods

Observer methods have the following signature:

app/components/my-component.js
import Component from '@ember/component';

export default Component.extend({
  init() {
    this._super(...arguments);
    this.addObserver('foo', this, 'fooDidChange');
  },

  fooDidChange(sender, key, value, rev) {
    // your code
  }
});

The sender is the object that changed. The key is the property that changes. The value property is currently reserved and unused. The rev is the last property revision of the object when it changed, which you can use to detect if the key value has really changed or not.

Usually you will not need the value or revision parameters at the end. In this case, it is common to write observer methods that take only a sender and key value as parameters or, if you aren't interested in any of these values, to write an observer that has no parameters at all.

cacheFor (keyName) : Object public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:489

keyName
String
returns
Object

The cached value of the computed property, if any

Returns the cached value of a computed property, if it exists. This allows you to inspect the value of a computed property without accidentally invoking it if it is intended to be generated lazily.

decrementProperty (keyName, decrement) : Number public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:452

keyName
String

The name of the property to decrement

decrement
Number

The amount to decrement by. Defaults to 1

returns
Number

The new property value

Set the value of a property to the current value minus some amount.

player.decrementProperty('lives');
orc.decrementProperty('health', 5);

destroy : EmberObject public

Module: @ember/engine

Inherited from CoreObject packages/ember-runtime/lib/system/core_object.js:445

returns
EmberObject

receiver

Destroys an object by setting the isDestroyed flag and removing its metadata, which effectively destroys observers and bindings.

If you try to set a property on a destroyed object, an exception will be raised.

Note that destruction is scheduled for the end of the run loop and does not happen immediately. It will set an isDestroying flag immediately.

get (keyName) : Object public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:94

keyName
String

The property to retrieve

returns
Object

The property value or undefined.

Retrieves the value of a property from the object.

This method is usually similar to using object[keyName] or object.keyName, however it supports both computed properties and the unknownProperty handler.

Because get unifies the syntax for accessing all these kinds of properties, it can make many refactorings easier, such as replacing a simple property with a computed property, or vice versa.

Computed Properties

Computed properties are methods defined with the property modifier declared at the end, such as:

fullName: Ember.computed('firstName', 'lastName', function() {
  return this.get('firstName') + ' ' + this.get('lastName');
})

When you call get on a computed property, the function will be called and the return value will be returned instead of the function itself.

Unknown Properties

Likewise, if you try to call get on a property whose value is undefined, the unknownProperty() method will be called on the object. If this method returns any value other than undefined, it will be returned instead. This allows you to implement "virtual" properties that are not defined upfront.

getProperties (list) : Object public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:137

list
String...|Array

of keys to get

returns
Object

To get the values of multiple properties at once, call getProperties with a list of strings or an array:

record.getProperties('firstName', 'lastName', 'zipCode');
// { firstName: 'John', lastName: 'Doe', zipCode: '10011' }

is equivalent to:

record.getProperties(['firstName', 'lastName', 'zipCode']);
// { firstName: 'John', lastName: 'Doe', zipCode: '10011' }

getWithDefault (keyName, defaultValue) : Object public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:414

keyName
String

The name of the property to retrieve

defaultValue
Object

The value to return if the property value is undefined

returns
Object

The property value or the defaultValue.

Retrieves the value of a property, or a default value in the case that the property returns undefined.

person.getWithDefault('lastName', 'Doe');

hasRegistration (fullName) : Boolean public

Module: @ember/engine

Inherited from RegistryProxyMixin packages/ember-runtime/lib/mixins/registry_proxy.js:111

fullName
String
returns
Boolean

Check if a factory is registered.

incrementProperty (keyName, increment) : Number public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:432

keyName
String

The name of the property to increment

increment
Number

The amount to increment by. Defaults to 1

returns
Number

The new property value

Set the value of a property to the current value plus some amount.

person.incrementProperty('age');
team.incrementProperty('score', 2);

init public

Module: @ember/engine

Inherited from CoreObject packages/ember-runtime/lib/system/core_object.js:210

An overridable method called when objects are instantiated. By default, does nothing unless it is overridden during class definition.

Example:

const Person = Ember.Object.extend({
  init() {
    alert(`Name is ${this.get('name')}`);
  }
});

let steve = Person.create({
  name: 'Steve'
});

// alerts 'Name is Steve'.

NOTE: If you do override init for a framework class like Ember.View, be sure to call this._super(...arguments) in your init declaration! If you don't, Ember may not have an opportunity to do important setup work, and you'll see strange behavior in your application.

inject (factoryNameOrType, property, injectionName) public

Module: @ember/engine

Inherited from RegistryProxyMixin packages/ember-runtime/lib/mixins/registry_proxy.js:193

factoryNameOrType
String
property
String
injectionName
String

Define a dependency injection onto a specific factory or all factories of a type.

When Ember instantiates a controller, view, or other framework component it can attach a dependency to that component. This is often used to provide services to a set of framework components.

An example of providing a session object to all controllers:

let App = Ember.Application.create();
let Session = Ember.Object.extend({ isAuthenticated: false });

// A factory must be registered before it can be injected
App.register('session:main', Session);

// Inject 'session:main' onto all factories of the type 'controller'
// with the name 'session'
App.inject('controller', 'session', 'session:main');

App.IndexController = Ember.Controller.extend({
  isLoggedIn: Ember.computed.alias('session.isAuthenticated')
});

Injections can also be performed on specific factories.

App.inject(<full_name or type>, <property name>, <full_name>)
App.inject('route', 'source', 'source:main')
App.inject('route:application', 'email', 'model:email')

It is important to note that injections can only be performed on classes that are instantiated by Ember itself. Instantiating a class directly (via create or new) bypasses the dependency injection system.

lookup (fullName, options) : Any public

Module: @ember/engine

Inherited from ContainerProxyMixin packages/ember-runtime/lib/mixins/container_proxy.js:49

fullName
String
options
Object
returns
Any

Given a fullName return a corresponding instance.

The default behavior is for lookup to return a singleton instance. The singleton is scoped to the container, allowing multiple containers to all have their own locally scoped singletons.

let registry = new Registry();
let container = registry.container();

registry.register('api:twitter', Twitter);

let twitter = container.lookup('api:twitter');

twitter instanceof Twitter; // => true

// by default the container will return singletons
let twitter2 = container.lookup('api:twitter');
twitter2 instanceof Twitter; // => true

twitter === twitter2; //=> true

If singletons are not wanted an optional flag can be provided at lookup.

let registry = new Registry();
let container = registry.container();

registry.register('api:twitter', Twitter);

let twitter = container.lookup('api:twitter', { singleton: false });
let twitter2 = container.lookup('api:twitter', { singleton: false });

twitter === twitter2; //=> false

notifyPropertyChange (keyName) : Observable public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:316

keyName
String

The property key to be notified about.

returns
Observable

Convenience method to call propertyWillChange and propertyDidChange in succession.

ownerInjection : Object public

Module: @ember/engine

Inherited from ContainerProxyMixin packages/ember-runtime/lib/mixins/container_proxy.js:25

Available since v2.3.0

returns
Object

Returns an object that can be used to provide an owner to a manually created instance.

Example:

let owner = Ember.getOwner(this);

User.create(
  owner.ownerInjection(),
  { username: 'rwjblue' }
)

register (fullName, factory, options) public

Module: @ember/engine

Inherited from RegistryProxyMixin packages/ember-runtime/lib/mixins/registry_proxy.js:30

fullName
String

type:name (e.g., 'model:user')

factory
Function

(e.g., App.Person)

options
Object

(optional) disable instantiation or singleton usage

Registers a factory that can be used for dependency injection (with inject) or for service lookup. Each factory is registered with a full name including two parts: type:name.

A simple example:

let App = Ember.Application.create();

App.Orange = Ember.Object.extend();
App.register('fruit:favorite', App.Orange);

Ember will resolve factories from the App namespace automatically. For example App.CarsController will be discovered and returned if an application requests controller:cars.

An example of registering a controller with a non-standard name:

let App = Ember.Application.create();
let Session = Ember.Controller.extend();

App.register('controller:session', Session);

// The Session controller can now be treated like a normal controller,
// despite its non-standard name.
App.ApplicationController = Ember.Controller.extend({
  needs: ['session']
});

Registered factories are instantiated by having create called on them. Additionally they are singletons, each time they are looked up they return the same instance.

Some examples modifying that default behavior:

let App = Ember.Application.create();

App.Person = Ember.Object.extend();
App.Orange = Ember.Object.extend();
App.Email = Ember.Object.extend();
App.session = Ember.Object.create();

App.register('model:user', App.Person, { singleton: false });
App.register('fruit:favorite', App.Orange);
App.register('communication:main', App.Email, { singleton: false });
App.register('session', App.session, { instantiate: false });

registerOptions (fullName, options) public

Module: @ember/engine

Inherited from RegistryProxyMixin packages/ember-runtime/lib/mixins/registry_proxy.js:132

fullName
String
options
Object

Register options for a particular factory.

registerOptionsForType (type, options) public

Module: @ember/engine

Inherited from RegistryProxyMixin packages/ember-runtime/lib/mixins/registry_proxy.js:152

type
String
options
Object

Allow registering options for all factories of a type.

let App = Ember.Application.create();
let appInstance = App.buildInstance();

// if all of type `connection` must not be singletons
appInstance.registerOptionsForType('connection', { singleton: false });

appInstance.register('connection:twitter', TwitterConnection);
appInstance.register('connection:facebook', FacebookConnection);

let twitter = appInstance.lookup('connection:twitter');
let twitter2 = appInstance.lookup('connection:twitter');

twitter === twitter2; // => false

let facebook = appInstance.lookup('connection:facebook');
let facebook2 = appInstance.lookup('connection:facebook');

facebook === facebook2; // => false

registeredOption (fullName, optionName) : Object public

Module: @ember/engine

Inherited from RegistryProxyMixin packages/ember-runtime/lib/mixins/registry_proxy.js:121

fullName
String
optionName
String
returns
Object

options

Return a specific registered option for a particular factory.

registeredOptions (fullName) : Object public

Module: @ember/engine

Inherited from RegistryProxyMixin packages/ember-runtime/lib/mixins/registry_proxy.js:142

fullName
String
returns
Object

options

Return registered options for a particular factory.

registeredOptionsForType (type) : Object public

Module: @ember/engine

Inherited from RegistryProxyMixin packages/ember-runtime/lib/mixins/registry_proxy.js:183

type
String
returns
Object

options

Return the registered options for all factories of a type.

removeObserver (key, target, method) : Ember.Observable public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:382

key
String

The key to observe

target
Object

The target object to invoke

method
String|Function

The method to invoke

returns
Ember.Observable

Remove an observer you have previously registered on this object. Pass the same key, target, and method you passed to addObserver() and your target will no longer receive notifications.

resolveRegistration (fullName) : Function public

Module: @ember/engine

Inherited from RegistryProxyMixin packages/ember-runtime/lib/mixins/registry_proxy.js:20

fullName
String
returns
Function

fullName's factory

Given a fullName return the corresponding factory.

set (keyName, value) : Object public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:162

keyName
String

The property to set

value
Object

The value to set or null.

returns
Object

The passed value

Sets the provided key or path to the value.

record.set("key", value);

This method is generally very similar to calling object["key"] = value or object.key = value, except that it provides support for computed properties, the setUnknownProperty() method and property observers.

Computed Properties

If you try to set a value on a key that has a computed property handler defined (see the get() method for an example), then set() will call that method, passing both the value and key instead of simply changing the value itself. This is useful for those times when you need to implement a property that is composed of one or more member properties.

Unknown Properties

If you try to set a value on a key that is undefined in the target object, then the setUnknownProperty() handler will be called instead. This gives you an opportunity to implement complex "virtual" properties that are not predefined on the object. If setUnknownProperty() returns undefined, then set() will simply set the value on the object.

Property Observers

In addition to changing the property, set() will also register a property change with the object. Unless you have placed this call inside of a beginPropertyChanges() and endPropertyChanges(), any "local" observers (i.e. observer methods declared on the same object), will be called immediately. Any "remote" observers (i.e. observer methods declared on another object) will be placed in a queue and called at a later time in a coalesced manner.

setProperties (hash) : Object public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:211

hash
Object

the hash of keys and values to set

returns
Object

The passed in hash

Sets a list of properties at once. These properties are set inside a single beginPropertyChanges and endPropertyChanges batch, so observers will be buffered.

record.setProperties({ firstName: 'Charles', lastName: 'Jolley' });

toString : String public

Module: @ember/engine

Inherited from CoreObject packages/ember-runtime/lib/system/core_object.js:498

returns
String

string representation

Returns a string representation which attempts to provide more information than Javascript's toString typically does, in a generic way for all Ember objects.

const Person = Ember.Object.extend()
person = Person.create()
person.toString() //=> "<Person:ember1024>"

If the object's class is not defined on an Ember namespace, it will indicate it is a subclass of the registered superclass:

const Student = Person.extend()
let student = Student.create()
student.toString() //=> "<(subclass of Person):ember1025>"

If the method toStringExtension is defined, its return value will be included in the output.

const Teacher = Person.extend({
  toStringExtension() {
    return this.get('fullName');
  }
});
teacher = Teacher.create()
teacher.toString(); //=> "<Teacher:ember1026:Tom Dale>"

toggleProperty (keyName) : Boolean public

Module: @ember/engine

Inherited from Observable packages/ember-runtime/lib/mixins/observable.js:472

keyName
String

The name of the property to toggle

returns
Boolean

The new property value

Set the value of a boolean property to the opposite of its current value.

starship.toggleProperty('warpDriveEngaged');

unregister (fullName) public

Module: @ember/engine

Defined in packages/ember-application/lib/system/engine-instance.js:116

fullName
String

Unregister a factory.

Overrides RegistryProxy#unregister in order to clear any cached instances of the unregistered factory.

willDestroy public

Module: @ember/engine

Inherited from CoreObject packages/ember-runtime/lib/system/core_object.js:471

Override to implement teardown.

Properties

concatenatedProperties public

Module: @ember/engine

Inherited from CoreObject packages/ember-runtime/lib/system/core_object.js:248

Defines the properties that will be concatenated from the superclass (instead of overridden).

By default, when you extend an Ember class a property defined in the subclass overrides a property with the same name that is defined in the superclass. However, there are some cases where it is preferable to build up a property's value by combining the superclass' property value with the subclass' value. An example of this in use within Ember is the classNames property of Ember.View.

Here is some sample code showing the difference between a concatenated property and a normal one:

const Bar = Ember.Object.extend({
  // Configure which properties to concatenate
  concatenatedProperties: ['concatenatedProperty'],

  someNonConcatenatedProperty: ['bar'],
  concatenatedProperty: ['bar']
});

const FooBar = Bar.extend({
  someNonConcatenatedProperty: ['foo'],
  concatenatedProperty: ['foo']
});

let fooBar = FooBar.create();
fooBar.get('someNonConcatenatedProperty'); // ['foo']
fooBar.get('concatenatedProperty'); // ['bar', 'foo']

This behavior extends to object creation as well. Continuing the above example:

let fooBar = FooBar.create({
  someNonConcatenatedProperty: ['baz'],
  concatenatedProperty: ['baz']
})
fooBar.get('someNonConcatenatedProperty'); // ['baz']
fooBar.get('concatenatedProperty'); // ['bar', 'foo', 'baz']

Adding a single property that is not an array will just add it in the array:

let fooBar = FooBar.create({
  concatenatedProperty: 'baz'
})
view.get('concatenatedProperty'); // ['bar', 'foo', 'baz']

Using the concatenatedProperties property, we can tell Ember to mix the content of the properties.

In Ember.Component the classNames, classNameBindings and attributeBindings properties are concatenated.

This feature is available for you to use throughout the Ember object model, although typical app developers are likely to use it infrequently. Since it changes expectations about behavior of properties, you should properly document its usage in each individual concatenated property (to not mislead your users to think they can override the property in a subclass).

isDestroyed public

Module: @ember/engine

Inherited from CoreObject packages/ember-runtime/lib/system/core_object.js:395

Destroyed object property flag.

if this property is true the observers and bindings were already removed by the effect of calling the destroy() method.

isDestroying public

Module: @ember/engine

Inherited from CoreObject packages/ember-runtime/lib/system/core_object.js:420

Destruction scheduled flag. The destroy() method has been called.

The object stays intact until the end of the run loop at which point the isDestroyed flag is set.

mergedProperties public

Module: @ember/engine

Inherited from CoreObject packages/ember-runtime/lib/system/core_object.js:321

Defines the properties that will be merged from the superclass (instead of overridden).

By default, when you extend an Ember class a property defined in the subclass overrides a property with the same name that is defined in the superclass. However, there are some cases where it is preferable to build up a property's value by merging the superclass property value with the subclass property's value. An example of this in use within Ember is the queryParams property of routes.

Here is some sample code showing the difference between a merged property and a normal one:

const Bar = Ember.Object.extend({
  // Configure which properties are to be merged
  mergedProperties: ['mergedProperty'],

  someNonMergedProperty: {
    nonMerged: 'superclass value of nonMerged'
  },
  mergedProperty: {
    page: { replace: false },
    limit: { replace: true }
  }
});

const FooBar = Bar.extend({
  someNonMergedProperty: {
    completelyNonMerged: 'subclass value of nonMerged'
  },
  mergedProperty: {
    limit: { replace: false }
  }
});

let fooBar = FooBar.create();

fooBar.get('someNonMergedProperty');
// => { completelyNonMerged: 'subclass value of nonMerged' }
//
// Note the entire object, including the nonMerged property of
// the superclass object, has been replaced

fooBar.get('mergedProperty');
// => {
//   page: {replace: false},
//   limit: {replace: false}
// }
//
// Note the page remains from the superclass, and the
// `limit` property's value of `false` has been merged from
// the subclass.

This behavior is not available during object create calls. It is only available at extend time.

In Ember.Route the queryParams property is merged.

This feature is available for you to use throughout the Ember object model, although typical app developers are likely to use it infrequently. Since it changes expectations about behavior of properties, you should properly document its usage in each individual merged property (to not mislead your users to think they can override the property in a subclass).

On this page


Methods

  • addObserver
  • cacheFor
  • decrementProperty
  • destroy
  • get
  • getProperties
  • getWithDefault
  • hasRegistration
  • incrementProperty
  • init
  • inject
  • lookup
  • notifyPropertyChange
  • ownerInjection
  • register
  • registerOptions
  • registerOptionsForType
  • registeredOption
  • registeredOptions
  • registeredOptionsForType
  • removeObserver
  • resolveRegistration
  • set
  • setProperties
  • toString
  • toggleProperty
  • unregister
  • willDestroy

Properties

  • concatenatedProperties
  • isDestroyed
  • isDestroying
  • mergedProperties
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