Class EmberArray

public
Uses: Enumerable
Defined in: packages/ember-runtime/lib/mixins/array.js:173
Module: @ember/array
Since: vEmber 0.9.0 
import EmberArray from '@ember/array';

This mixin implements Observer-friendly Array-like behavior. It is not a concrete implementation, but it can be used up by other classes that want to appear like arrays.

For example, ArrayProxy is a concrete classes that can be instantiated to implement array-like behavior. Both of these classes use the Array Mixin by way of the MutableArray mixin, which allows observable changes to be made to the underlying array.

Unlike Ember.Enumerable, this mixin defines methods specifically for collections that provide index-ordered access to their contents. When you are designing code that needs to accept any kind of Array-like object, you should use these methods instead of Array primitives because these will properly notify observers of changes to the array.

Although these methods are efficient, they do add a layer of indirection to your application so it is a good idea to use them only when you need the flexibility of using both true JavaScript arrays and "virtual" arrays such as controllers and collections.

You can use the methods defined in this module to access and modify array contents in a KVO-friendly way. You can also be notified whenever the membership of an array changes by using .observes('myArray.[]').

To support EmberArray in your own class, you must override two primitives to use it: length() and objectAt().

Note that the EmberArray mixin also incorporates the Ember.Enumerable mixin. All EmberArray-like objects are also enumerable.

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@each public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:595

Returns a special object that can be used to observe individual properties on the array. Just get an equivalent property on this object and it will return an enumerable that maps automatically to the named key on the member objects.

@each should only be used in a non-terminal context. Example:

myMethod: computed('posts.@each.author', function(){
  ...
});

If you merely want to watch for the array being changed, like an object being replaced, added or removed, use [] instead of @each.

myMethod: computed('posts.[]', function(){
  ...
});

[] public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:280

returns

this

This is the handler for the special array content property. If you get this property, it will return this. If you set this property to a new array, it will replace the current content.

This property overrides the default property defined in Ember.Enumerable.

firstObject Object public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:133

returns
Object

the object or undefined

Helper method returns the first object from a collection. This is usually used by bindings and other parts of the framework to extract a single object if the enumerable contains only one item.

If you override this method, you should implement it so that it will always return the same value each time it is called. If your enumerable contains only one object, this method should always return that object. If your enumerable is empty, this method should return undefined.

let arr = ['a', 'b', 'c'];
arr.get('firstObject');  // 'a'

let arr = [];
arr.get('firstObject');  // undefined

hasArrayObservers public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:499

Becomes true whenever the array currently has observers watching changes on the array.

lastObject Object public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:170

returns
Object

the last object or undefined

Helper method returns the last object from a collection. If your enumerable contains only one object, this method should always return that object. If your enumerable is empty, this method should return undefined.

let arr = ['a', 'b', 'c'];
arr.get('lastObject');  // 'c'

let arr = [];
arr.get('lastObject');  // undefined

length public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:213

Required. You must implement this method to apply this mixin.

Your array must support the length property. Your replace methods should set this property whenever it changes.