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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.


Methods

addArrayObserver (target, opts) : EmberArray public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:453

target
Object

The observer object.

opts
Object

Optional hash of configuration options including willChange and didChange option.

returns
EmberArray

receiver

Adds an array observer to the receiving array. The array observer object normally must implement two methods:

  • arrayWillChange(observedObj, start, removeCount, addCount) - This method will be called just before the array is modified.
  • arrayDidChange(observedObj, start, removeCount, addCount) - This method will be called just after the array is modified.

Both callbacks will be passed the observed object, starting index of the change as well as a count of the items to be removed and added. You can use these callbacks to optionally inspect the array during the change, clear caches, or do any other bookkeeping necessary.

In addition to passing a target, you can also include an options hash which you can use to override the method names that will be invoked on the target.

any (callback, target) : Boolean public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:614

callback
Function

The callback to execute

target
Object

The target object to use

returns
Boolean

true if the passed function returns true for any item

Returns true if the passed function returns true for any item in the enumeration.

The callback method you provide should have the following signature (all parameters are optional):

function(item, index, enumerable);
  • item is the current item in the iteration.
  • index is the current index in the iteration.
  • enumerable is the enumerable object itself.

It must return a truthy value (i.e. true) to include an item in the results. Any non-truthy return value will discard the item from the results.

Note that in addition to a callback, you can also pass an optional target object that will be set as this on the context. This is a good way to give your iterator function access to the current object.

Usage Example:

if (people.any(isManager)) {
  Paychecks.addBiggerBonus();
}

arrayContentDidChange (startIdx, removeAmt, addAmt) : EmberArray public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:529

startIdx
Number

The starting index in the array that did change.

removeAmt
Number

The number of items that were removed. If you pass null assumes 0

addAmt
Number

The number of items that were added. If you pass null assumes 0.

returns
EmberArray

receiver

If you are implementing an object that supports EmberArray, call this method just after the array content changes to notify any observers and invalidate any related properties. Pass the starting index of the change as well as a delta of the amounts to change.

arrayContentWillChange (startIdx, removeAmt, addAmt) : EmberArray public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:510

startIdx
Number

The starting index in the array that will change.

removeAmt
Number

The number of items that will be removed. If you pass null assumes 0

addAmt
Number

The number of items that will be added. If you pass null assumes 0.

returns
EmberArray

receiver

If you are implementing an object that supports EmberArray, call this method just before the array content changes to notify any observers and invalidate any related properties. Pass the starting index of the change as well as a delta of the amounts to change.

compact : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:778

returns
Array

the array without null and undefined elements.

Returns a copy of the array with all null and undefined elements removed.

let arr = ['a', null, 'c', undefined];
arr.compact();  // ['a', 'c']

every (callback, target) : Boolean public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:554

callback
Function

The callback to execute

target
Object

The target object to use

returns
Boolean

Returns true if the passed function returns true for every item in the enumeration. This corresponds with the every() method in JavaScript 1.6.

The callback method you provide should have the following signature (all parameters are optional):

function(item, index, enumerable);
  • item is the current item in the iteration.
  • index is the current index in the iteration.
  • enumerable is the enumerable object itself.

It should return the true or false.

Note that in addition to a callback, you can also pass an optional target object that will be set as this on the context. This is a good way to give your iterator function access to the current object.

Example Usage:

if (people.every(isEngineer)) {
  Paychecks.addBigBonus();
}

filter (callback, target) : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:365

callback
Function

The callback to execute

target
Object

The target object to use

returns
Array

A filtered array.

Returns an array with all of the items in the enumeration that the passed function returns true for. This method corresponds to filter() defined in JavaScript 1.6.

The callback method you provide should have the following signature (all parameters are optional):

function(item, index, enumerable);
  • item is the current item in the iteration.
  • index is the current index in the iteration.
  • enumerable is the enumerable object itself.

It should return true to include the item in the results, false otherwise.

Note that in addition to a callback, you can also pass an optional target object that will be set as this on the context. This is a good way to give your iterator function access to the current object.

filterBy (key, value) : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:443

key
String

the property to test

value
*

optional value to test against.

returns
Array

filtered array

Returns an array with just the items with the matched property. You can pass an optional second argument with the target value. Otherwise this will match any property that evaluates to true.

find (callback, target) : Object public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:477

callback
Function

The callback to execute

target
Object

The target object to use

returns
Object

Found item or undefined.

Returns the first item in the array for which the callback returns true. This method works similar to the filter() method defined in JavaScript 1.6 except that it will stop working on the array once a match is found.

The callback method you provide should have the following signature (all parameters are optional):

function(item, index, enumerable);
  • item is the current item in the iteration.
  • index is the current index in the iteration.
  • enumerable is the enumerable object itself.

It should return the true to include the item in the results, false otherwise.

Note that in addition to a callback, you can also pass an optional target object that will be set as this on the context. This is a good way to give your iterator function access to the current object.

findBy (key, value) : Object public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:537

key
String

the property to test

value
String

optional value to test against.

returns
Object

found item or undefined

Returns the first item with a property matching the passed value. You can pass an optional second argument with the target value. Otherwise this will match any property that evaluates to true.

This method works much like the more generic find() method.

forEach (callback, target) : Object public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:240

callback
Function

The callback to execute

target
Object

The target object to use

returns
Object

receiver

Iterates through the enumerable, calling the passed function on each item. This method corresponds to the forEach() method defined in JavaScript 1.6.

The callback method you provide should have the following signature (all parameters are optional):

function(item, index, enumerable);
  • item is the current item in the iteration.
  • index is the current index in the iteration.
  • enumerable is the enumerable object itself.

Note that in addition to a callback, you can also pass an optional target object that will be set as this on the context. This is a good way to give your iterator function access to the current object.

getEach (key) : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:289

key
String

name of the property

returns
Array

The mapped array.

Alias for mapBy

includes (obj, startAt) : Boolean public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:548

obj
Object

The object to search for.

startAt
Number

optional starting location to search, default 0

returns
Boolean

true if object is found in the array.

Returns true if the passed object can be found in the array. This method is a Polyfill for ES 2016 Array.includes. If no startAt argument is given, the starting location to search is 0. If it's negative, searches from the index of this.length + startAt by asc.

[1, 2, 3].includes(2);     // true
[1, 2, 3].includes(4);     // false
[1, 2, 3].includes(3, 2);  // true
[1, 2, 3].includes(3, 3);  // false
[1, 2, 3].includes(3, -1); // true
[1, 2, 3].includes(1, -1); // false
[1, 2, 3].includes(1, -4); // true
[1, 2, NaN].includes(NaN); // true

indexOf (object, startAt) : Number public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:363

object
Object

the item to search for

startAt
Number

optional starting location to search, default 0

returns
Number

index or -1 if not found

Returns the index of the given object's first occurrence. If no startAt argument is given, the starting location to search is 0. If it's negative, will count backward from the end of the array. Returns -1 if no match is found.

let arr = ['a', 'b', 'c', 'd', 'a'];

arr.indexOf('a');       //  0
arr.indexOf('z');       // -1
arr.indexOf('a', 2);    //  4
arr.indexOf('a', -1);   //  4
arr.indexOf('b', 3);    // -1
arr.indexOf('a', 100);  // -1

invoke (methodName, args) : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:737

methodName
String

the name of the method

args
Object...

optional arguments to pass as well.

returns
Array

return values from calling invoke.

Invokes the named method on every object in the receiver that implements it. This method corresponds to the implementation in Prototype 1.6.

isAny (key, value) : Boolean public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:675

Available since v1.3.0

key
String

the property to test

value
String

optional value to test against. Defaults to true

returns
Boolean

Returns true if the passed property resolves to the value of the second argument for any item in the enumerable. This method is often simpler/faster than using a callback.

isEvery (key, value) : Boolean public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:595

Available since v1.3.0

key
String

the property to test

value
String

optional value to test against. Defaults to true

returns
Boolean

Returns true if the passed property resolves to the value of the second argument for all items in the enumerable. This method is often simpler/faster than using a callback.

Note that like the native Array.every, isEvery will return true when called on any empty enumerable.

lastIndexOf (object, startAt) : Number public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:406

object
Object

the item to search for

startAt
Number

optional starting location to search, default 0

returns
Number

index or -1 if not found

Returns the index of the given object's last occurrence. If no startAt argument is given, the search starts from the last position. If it's negative, will count backward from the end of the array. Returns -1 if no match is found.

let arr = ['a', 'b', 'c', 'd', 'a'];

arr.lastIndexOf('a');       //  4
arr.lastIndexOf('z');       // -1
arr.lastIndexOf('a', 2);    //  0
arr.lastIndexOf('a', -1);   //  4
arr.lastIndexOf('b', 3);    //  1
arr.lastIndexOf('a', 100);  //  4

map (callback, target) : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:315

callback
Function

The callback to execute

target
Object

The target object to use

returns
Array

The mapped array.

Maps all of the items in the enumeration to another value, returning a new array. This method corresponds to map() defined in JavaScript 1.6.

The callback method you provide should have the following signature (all parameters are optional):

function(item, index, enumerable);
  • item is the current item in the iteration.
  • index is the current index in the iteration.
  • enumerable is the enumerable object itself.

It should return the mapped value.

Note that in addition to a callback, you can also pass an optional target object that will be set as this on the context. This is a good way to give your iterator function access to the current object.

mapBy (key) : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:352

key
String

name of the property

returns
Array

The mapped array.

Similar to map, this specialized function returns the value of the named property on all items in the enumeration.

objectAt (idx) : * public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:224

idx
Number

The index of the item to return.

returns
*

item at index or undefined

Returns the object at the given index. If the given index is negative or is greater or equal than the array length, returns undefined.

This is one of the primitives you must implement to support EmberArray. If your object supports retrieving the value of an array item using get() (i.e. myArray.get(0)), then you do not need to implement this method yourself.

let arr = ['a', 'b', 'c', 'd'];

arr.objectAt(0);   // 'a'
arr.objectAt(3);   // 'd'
arr.objectAt(-1);  // undefined
arr.objectAt(4);   // undefined
arr.objectAt(5);   // undefined

objectsAt (indexes) : Array public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:256

indexes
Array

An array of indexes of items to return.

returns
Array

This returns the objects at the specified indexes, using objectAt.

let arr = ['a', 'b', 'c', 'd'];

arr.objectsAt([0, 1, 2]);  // ['a', 'b', 'c']
arr.objectsAt([2, 3, 4]);  // ['c', 'd', undefined]

reduce (callback, initialValue, reducerProperty) : Object public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:691

callback
Function

The callback to execute

initialValue
Object

Initial value for the reduce

reducerProperty
String

internal use only.

returns
Object

The reduced value.

This will combine the values of the enumerator into a single value. It is a useful way to collect a summary value from an enumeration. This corresponds to the reduce() method defined in JavaScript 1.8.

The callback method you provide should have the following signature (all parameters are optional):

function(previousValue, item, index, enumerable);
  • previousValue is the value returned by the last call to the iterator.
  • item is the current item in the iteration.
  • index is the current index in the iteration.
  • enumerable is the enumerable object itself.

Return the new cumulative value.

In addition to the callback you can also pass an initialValue. An error will be raised if you do not pass an initial value and the enumerator is empty.

Note that unlike the other methods, this method does not allow you to pass a target object to set as this for the callback. It's part of the spec. Sorry.

reject (callback, target) : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:408

callback
Function

The callback to execute

target
Object

The target object to use

returns
Array

A rejected array.

Returns an array with all of the items in the enumeration where the passed function returns false. This method is the inverse of filter().

The callback method you provide should have the following signature (all parameters are optional):

function(item, index, enumerable);
  • item is the current item in the iteration.
  • index is the current index in the iteration
  • enumerable is the enumerable object itself.

It should return a falsey value to include the item in the results.

Note that in addition to a callback, you can also pass an optional target object that will be set as "this" on the context. This is a good way to give your iterator function access to the current object.

rejectBy (key, value) : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:458

key
String

the property to test

value
String

optional value to test against.

returns
Array

rejected array

Returns an array with the items that do not have truthy values for key. You can pass an optional second argument with the target value. Otherwise this will match any property that evaluates to false.

removeArrayObserver (target, opts) : EmberArray public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:483

target
Object

The object observing the array.

opts
Object

Optional hash of configuration options including willChange and didChange option.

returns
EmberArray

receiver

Removes an array observer from the object if the observer is current registered. Calling this method multiple times with the same object will have no effect.

setEach (key, value) : Object public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:299

key
String

The key to set

value
Object

The object to set

returns
Object

receiver

Sets the value on the named property for each member. This is more ergonomic than using other methods defined on this helper. If the object implements Ember.Observable, the value will be changed to set(), otherwise it will be set directly. null objects are skipped.

slice (beginIndex, endIndex) : Array public

Module: @ember/array

Defined in packages/ember-runtime/lib/mixins/array.js:321

beginIndex
Number

(Optional) index to begin slicing from.

endIndex
Number

(Optional) index to end the slice at (but not included).

returns
Array

New array with specified slice

Returns a new array that is a slice of the receiver. This implementation uses the observable array methods to retrieve the objects for the new slice.

let arr = ['red', 'green', 'blue'];

arr.slice(0);       // ['red', 'green', 'blue']
arr.slice(0, 2);    // ['red', 'green']
arr.slice(1, 100);  // ['green', 'blue']

sortBy (property) : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:1052

Available since v1.2.0

property
String

name(s) to sort on

returns
Array

The sorted array.

Converts the enumerable into an array and sorts by the keys specified in the argument.

You may provide multiple arguments to sort by multiple properties.

toArray : Array public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:762

returns
Array

the enumerable as an array.

Simply converts the enumerable into a genuine array. The order is not guaranteed. Corresponds to the method implemented by Prototype.

uniq : Ember.Enumerable public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:826

returns
Ember.Enumerable

Returns a new enumerable that contains only unique values. The default implementation returns an array regardless of the receiver type.

let arr = ['a', 'a', 'b', 'b'];
arr.uniq();  // ['a', 'b']

This only works on primitive data types, e.g. Strings, Numbers, etc.

uniqBy : Ember.Enumerable public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:1083

returns
Ember.Enumerable

Returns a new enumerable that contains only items containing a unique property value. The default implementation returns an array regardless of the receiver type.

let arr = [{ value: 'a' }, { value: 'a' }, { value: 'b' }, { value: 'b' }];
arr.uniqBy('value');  // [{ value: 'a' }, { value: 'b' }]

without (value) : Ember.Enumerable public

Module: @ember/array

Inherited from Enumerable packages/ember-runtime/lib/mixins/enumerable.js:794

value
Object
returns
Ember.Enumerable

Returns a new enumerable that excludes the passed value. The default implementation returns an array regardless of the receiver type. If the receiver does not contain the value it returns the original enumerable.

let arr = ['a', 'b', 'a', 'c'];
arr.without('a');  // ['b', 'c']

Properties

@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.

On this page


Methods

  • addArrayObserver
  • any
  • arrayContentDidChange
  • arrayContentWillChange
  • compact
  • every
  • filter
  • filterBy
  • find
  • findBy
  • forEach
  • getEach
  • includes
  • indexOf
  • invoke
  • isAny
  • isEvery
  • lastIndexOf
  • map
  • mapBy
  • objectAt
  • objectsAt
  • reduce
  • reject
  • rejectBy
  • removeArrayObserver
  • setEach
  • slice
  • sortBy
  • toArray
  • uniq
  • uniqBy
  • without

Properties

  • @each
  • []
  • firstObject
  • hasArrayObservers
  • lastObject
  • length
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