Class Ember.Array
This module implements Observer-friendly Array-like behavior. This mixin is picked up by the Array class as well as other controllers, etc. that want to appear to be arrays.
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 changing the syntax of the property to
.observes('*myProperty.[]')
.
To support Ember.Array
in your own class, you must override two
primitives to use it: replace()
and objectAt()
.
Note that the Ember.Array mixin also incorporates the Ember.Enumerable
mixin. All Ember.Array
-like objects are also enumerable.
@each
Defined in packages/ember-runtime/lib/mixins/array.js:409
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.
If you merely want to watch for any items being added or removed to the array,
use the []
property instead of @each
.
Boolean
Defined in packages/ember-runtime/lib/mixins/array.js:299
Becomes true whenever the array currently has observers watching changes on the array.
[]
Defined in packages/ember-runtime/lib/mixins/array.js:109
- 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 it a new array, it will replace the current content.
This property overrides the default property defined in Ember.Enumerable
.
firstObject Object
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:109
- 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
.
1 2 3 4 5 |
var arr = ["a", "b", "c"]; arr.get('firstObject'); // "a" var arr = []; arr.get('firstObject'); // undefined |
hasEnumerableObservers
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:879
Becomes true whenever the array currently has observers watching changes on the array.
lastObject Object
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:140
- 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
.
1 2 3 4 5 |
var arr = ["a", "b", "c"]; arr.get('lastObject'); // "c" var arr = []; arr.get('lastObject'); // undefined |
length
Defined in packages/ember-runtime/lib/mixins/array.js:51
Your array must support the length
property. Your replace methods should
set this property whenever it changes.