Ember.ArrayProxy Class packages/ember-runtime/lib/system/array_proxy.js:32


An ArrayProxy wraps any other object that implements Ember.Array and/or Ember.MutableArray, forwarding all requests. This makes it very useful for a number of binding use cases or other cases where being able to swap out the underlying array is useful.

A simple example of usage:

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var pets = ['dog', 'cat', 'fish'];
var ap = Ember.ArrayProxy.create({ content: Ember.A(pets) });

ap.get('firstObject');                        // 'dog'
ap.set('content', ['amoeba', 'paramecium']);
ap.get('firstObject');                        // 'amoeba'

This class can also be useful as a layer to transform the contents of an array, as they are accessed. This can be done by overriding objectAtContent:

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var pets = ['dog', 'cat', 'fish'];
var ap = Ember.ArrayProxy.create({
    content: Ember.A(pets),
    objectAtContent: function(idx) {
        return this.get('content').objectAt(idx).toUpperCase();
    }
});

ap.get('firstObject'); // . 'DOG'
Show:

_contentDidChange

private

Invoked when the content property changes. Notifies observers that the entire array content has changed.

_contentWillChange

private

Invoked when the content property is about to change. Notifies observers that the entire array content will change.

_scheduledDestroy

private

Invoked by the run loop to actually destroy the object. This is scheduled for execution by the destroy method.

addArrayObserver

(target, opts) Ember.Array

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 a 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.

Parameters:

target Object
The observer object.
opts Hash
Optional hash of configuration options including `willChange` and `didChange` option.

Returns:

Ember.Array
receiver

addEnumerableObserver

(target, opts)

Registers an enumerable observer. Must implement Ember.EnumerableObserver mixin.

Parameters:

target Object
opts [Hash]

Returns:

this

addObject

(obj) Ember.Array

Push the object onto the end of the array if it is not already present in the array.

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var cities = ["Chicago", "Berlin"];
cities.addObject("Lima");    // ["Chicago", "Berlin", "Lima"]
cities.addObject("Berlin");  // ["Chicago", "Berlin", "Lima"]

Parameters:

obj *
object to add, if not already present

Returns:

Ember.Array
receiver

addObjects

(objects) Object

Adds each object in the passed enumerable to the receiver.

Parameters:

objects Ember.Enumerable
the objects to add.

Returns:

Object
receiver

addObserver

(key, target, method)

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.

You can also pass an optional context parameter to this method. The context will be passed to your observer method whenever it is triggered. Note that if you add the same target/method pair on a key multiple times with different context parameters, your observer will only be called once with the last context you passed.

Observer Methods

Observer methods you pass should generally have the following signature if you do not pass a context parameter:

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fooDidChange: function(sender, key, value, rev) { };

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.

If you pass a context parameter, the context will be passed before the revision like so:

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fooDidChange: function(sender, key, value, context, rev) { };

Usually you will not need the value, context 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.

Parameters:

key String
The key to observer
target Object
The target object to invoke
method String|Function
The method to invoke.

any

(callback, target) Boolean

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

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

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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.

Usage Example:

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

Parameters:

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

anyBy

(key, value) Boolean deprecated

Use isAny instead

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Boolean
`true` if the passed function returns `true` for any item

arrayContentDidChange

(startIdx, removeAmt, addAmt) Ember.Array

If you are implementing an object that supports Ember.Array, 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.

Parameters:

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:

Ember.Array
receiver

arrayContentWillChange

(startIdx, removeAmt, addAmt) Ember.Array

If you are implementing an object that supports Ember.Array, 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.

Parameters:

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:

Ember.Array
receiver

beginPropertyChanges

Ember.Observable

Begins a grouping of property changes.

You can use this method to group property changes so that notifications will not be sent until the changes are finished. If you plan to make a large number of changes to an object at one time, you should call this method at the beginning of the changes to begin deferring change notifications. When you are done making changes, call endPropertyChanges() to deliver the deferred change notifications and end deferring.

Returns:

Ember.Observable

cacheFor

(keyName) Object

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.

Parameters:

keyName String

Returns:

Object
The cached value of the computed property, if any

clear

Ember.Array

Remove all elements from the array. This is useful if you want to reuse an existing array without having to recreate it.

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var colors = ["red", "green", "blue"];
color.length();   //  3
colors.clear();   //  []
colors.length();  //  0

Returns:

Ember.Array
An empty Array.

compact

Array

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

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

Returns:

Array
the array without null and undefined elements.

contains

(obj) Boolean

Returns true if the passed object can be found in the receiver. The default version will iterate through the enumerable until the object is found. You may want to override this with a more efficient version.

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var arr = ['a', 'b', 'c'];

arr.contains('a'); // true
arr.contains('z'); // false

Parameters:

obj Object
The object to search for.

Returns:

Boolean
`true` if object is found in enumerable.

contentArrayDidChange

(contentArray, start, removeCount, addCount)

Override to implement content array didChange observer.

Parameters:

contentArray Ember.Array
the content array
start Number
starting index of the change
removeCount Number
count of items removed
addCount Number
count of items added

contentArrayWillChange

(contentArray, start, removeCount, addCount)

Override to implement content array willChange observer.

Parameters:

contentArray Ember.Array
the content array
start Number
starting index of the change
removeCount Number
count of items removed
addCount Number
count of items added

create

(arguments) static

Creates an instance of a class. Accepts either no arguments, or an object containing values to initialize the newly instantiated object with.

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App.Person = Ember.Object.extend({
  helloWorld: function() {
    alert("Hi, my name is " + this.get('name'));
  }
});

var tom = App.Person.create({
  name: 'Tom Dale'
});

tom.helloWorld(); // alerts "Hi, my name is Tom Dale".

create will call the init function if defined during Ember.AnyObject.extend

If no arguments are passed to create, it will not set values to the new instance during initialization:

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var noName = App.Person.create();
noName.helloWorld(); // alerts undefined

NOTE: For performance reasons, you cannot declare methods or computed properties during create. You should instead declare methods and computed properties when using extend or use the createWithMixins shorthand.

Parameters:

arguments []

createWithMixins

(arguments) static

Equivalent to doing extend(arguments).create(). If possible use the normal create method instead.

Parameters:

arguments []

decrementProperty

(keyName, decrement) Number

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

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

Parameters:

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

destroy

Ember.Object

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.

Returns:

Ember.Object
receiver

eachComputedProperty

(callback, binding)

Iterate over each computed property for the class, passing its name and any associated metadata (see metaForProperty) to the callback.

Parameters:

callback Function
binding Object

endPropertyChanges

Ember.Observable

Ends a grouping of property changes.

You can use this method to group property changes so that notifications will not be sent until the changes are finished. If you plan to make a large number of changes to an object at one time, you should call beginPropertyChanges() at the beginning of the changes to defer change notifications. When you are done making changes, call this method to deliver the deferred change notifications and end deferring.

Returns:

Ember.Observable

enumerableContentDidChange

(removing, adding)

Invoke this method when the contents of your enumerable has changed. This will notify any observers watching for content changes. If you are implementing an ordered enumerable (such as an array), also pass the start and end values where the content changed so that it can be used to notify range observers.

Parameters:

removing Ember.Enumerable|Number
An enumerable of the objects to be removed or the number of items to be removed.
adding Ember.Enumerable|Number
An enumerable of the objects to be added or the number of items to be added.

enumerableContentWillChange

(removing, adding)

Invoke this method just before the contents of your enumerable will change. You can either omit the parameters completely or pass the objects to be removed or added if available or just a count.

Parameters:

removing Ember.Enumerable|Number
An enumerable of the objects to be removed or the number of items to be removed.
adding Ember.Enumerable|Number
An enumerable of the objects to be added or the number of items to be added.

every

(callback, target) 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):

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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:

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

Parameters:

callback Function
The callback to execute
target [Object]
The target object to use

Returns:

Boolean

everyBy

(key, value) Boolean deprecated

Use isEvery instead

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Boolean

everyProperty

(key, value) Boolean deprecated

Use isEvery instead

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Boolean

extend

(mixins, arguments) static

Creates a new subclass.

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App.Person = Ember.Object.extend({
  say: function(thing) {
    alert(thing);
   }
});

This defines a new subclass of Ember.Object: App.Person. It contains one method: say().

You can also create a subclass from any existing class by calling its extend() method. For example, you might want to create a subclass of Ember's built-in Ember.View class:

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App.PersonView = Ember.View.extend({
  tagName: 'li',
  classNameBindings: ['isAdministrator']
});

When defining a subclass, you can override methods but still access the implementation of your parent class by calling the special _super() method:

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App.Person = Ember.Object.extend({
  say: function(thing) {
    var name = this.get('name');
    alert(name + ' says: ' + thing);
  }
});

App.Soldier = App.Person.extend({
  say: function(thing) {
    this._super(thing + ", sir!");
  },
  march: function(numberOfHours) {
    alert(this.get('name') + ' marches for ' + numberOfHours + ' hours.')
  }
});

var yehuda = App.Soldier.create({
  name: "Yehuda Katz"
});

yehuda.say("Yes");  // alerts "Yehuda Katz says: Yes, sir!"

The create() on line #17 creates an instance of the App.Soldier class. The extend() on line #8 creates a subclass of App.Person. Any instance of the App.Person class will not have the march() method.

You can also pass Mixin classes to add additional properties to the subclass.

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App.Person = Ember.Object.extend({
  say: function(thing) {
    alert(this.get('name') + ' says: ' + thing);
  }
});

App.SingingMixin = Mixin.create({
  sing: function(thing){
    alert(this.get('name') + ' sings: la la la ' + thing);
  }
});

App.BroadwayStar = App.Person.extend(App.SingingMixin, {
  dance: function() {
    alert(this.get('name') + ' dances: tap tap tap tap ');
  }
});

The App.BroadwayStar class contains three methods: say(), sing(), and dance().

Parameters:

mixins [Mixin]
One or more Mixin classes
arguments [Object]
Object containing values to use within the new class

filter

(callback, target) 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):

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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.

Parameters:

callback Function
The callback to execute
target [Object]
The target object to use

Returns:

Array
A filtered array.

filterBy

(key, value) 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.

Parameters:

key String
the property to test
value [*]
optional value to test against.

Returns:

Array
filtered array

filterProperty

(key, value) Array deprecated

Use filterBy instead

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.

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Array
filtered array

find

(callback, target) Object

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):

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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.

Parameters:

callback Function
The callback to execute
target [Object]
The target object to use

Returns:

Object
Found item or `undefined`.

findBy

(key, value) Object

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.

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Object
found item or `undefined`

findProperty

(key, value) Object deprecated

Use findBy instead

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.

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Object
found item or `undefined`

forEach

(callback, target) Object

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):

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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.

Parameters:

callback Function
The callback to execute
target [Object]
The target object to use

Returns:

Object
receiver

get

(keyName) Object

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:

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

Parameters:

keyName String
The property to retrieve

Returns:

Object
The property value or undefined.

getEach

(key) Array

Alias for mapBy

Parameters:

key String
name of the property

Returns:

Array
The mapped array.

getProperties

(list) Hash

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

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

is equivalent to:

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

Parameters:

list String...|Array
of keys to get

Returns:

Hash

getWithDefault

(keyName, defaultValue) Object

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

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

Parameters:

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.

hasObserverFor

(key) Boolean

Returns true if the object currently has observers registered for a particular key. You can use this method to potentially defer performing an expensive action until someone begins observing a particular property on the object.

Parameters:

key String
Key to check

Returns:

Boolean

incrementProperty

(keyName, increment) Number

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

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

Parameters:

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

indexOf

(object, startAt) Number

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.

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var 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

Parameters:

object Object
the item to search for
startAt Number
optional starting location to search, default 0

Returns:

Number
index or -1 if not found

init

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

Example:

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App.Person = Ember.Object.extend({
  init: function() {
    alert('Name is ' + this.get('name'));
  }
});

var steve = App.Person.create({
  name: "Steve"
});

// alerts 'Name is Steve'.

NOTE: If you do override init for a framework class like Ember.View or Ember.ArrayController, be sure to call this._super() 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.

insertAt

(idx, object) Ember.Array

This will use the primitive replace() method to insert an object at the specified index.

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var colors = ["red", "green", "blue"];
colors.insertAt(2, "yellow");  // ["red", "green", "yellow", "blue"]
colors.insertAt(5, "orange");  // Error: Index out of range

Parameters:

idx Number
index of insert the object at.
object Object
object to insert

Returns:

Ember.Array
receiver

invoke

(methodName, args) Array

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

Parameters:

methodName String
the name of the method
args Object...
optional arguments to pass as well.

Returns:

Array
return values from calling invoke.

isAny

(key, value) Boolean

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

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Boolean
`true` if the passed function returns `true` for any item

isEvery

(key, value) Boolean

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

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Boolean

lastIndexOf

(object, startAt) Number

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.

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var 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

Parameters:

object Object
the item to search for
startAt Number
optional starting location to search, default 0

Returns:

Number
index or -1 if not found

lazyInjections

Object

Returns a hash of property names and container names that injected properties will lookup on the container lazily.

Returns:

Object
Hash of all lazy injected property keys to container names

map

(callback, target) 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):

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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.

Parameters:

callback Function
The callback to execute
target [Object]
The target object to use

Returns:

Array
The mapped array.

mapBy

(key) Array

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

Parameters:

key String
name of the property

Returns:

Array
The mapped array.

mapProperty

(key) Array deprecated

Use mapBy instead

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

Parameters:

key String
name of the property

Returns:

Array
The mapped array.

metaForProperty

(key)

In some cases, you may want to annotate computed properties with additional metadata about how they function or what values they operate on. For example, computed property functions may close over variables that are then no longer available for introspection.

You can pass a hash of these values to a computed property like this:

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person: function() {
  var personId = this.get('personId');
  return App.Person.create({ id: personId });
}.property().meta({ type: App.Person })

Once you've done this, you can retrieve the values saved to the computed property from your class like this:

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MyClass.metaForProperty('person');

This will return the original hash that was passed to meta().

Parameters:

key String
property name

nextObject

(index, previousObject, context) Object

Implement this method to make your class enumerable.

This method will be call repeatedly during enumeration. The index value will always begin with 0 and increment monotonically. You don't have to rely on the index value to determine what object to return, but you should always check the value and start from the beginning when you see the requested index is 0.

The previousObject is the object that was returned from the last call to nextObject for the current iteration. This is a useful way to manage iteration if you are tracing a linked list, for example.

Finally the context parameter will always contain a hash you can use as a "scratchpad" to maintain any other state you need in order to iterate properly. The context object is reused and is not reset between iterations so make sure you setup the context with a fresh state whenever the index parameter is 0.

Generally iterators will continue to call nextObject until the index reaches the your current length-1. If you run out of data before this time for some reason, you should simply return undefined.

The default implementation of this method simply looks up the index. This works great on any Array-like objects.

Parameters:

index Number
the current index of the iteration
previousObject Object
the value returned by the last call to `nextObject`.
context Object
a context object you can use to maintain state.

Returns:

Object
the next object in the iteration or undefined

notifyPropertyChange

(keyName) Ember.Observable

Convenience method to call propertyWillChange and propertyDidChange in succession.

Parameters:

keyName String
The property key to be notified about.

Returns:

Ember.Observable

objectAt

(idx) *

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 Ember.Array. 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.

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var 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

Parameters:

idx Number
The index of the item to return.

Returns:

*
item at index or undefined

objectAtContent

(idx) Object

Should actually retrieve the object at the specified index from the content. You can override this method in subclasses to transform the content item to something new.

This method will only be called if content is non-null.

Parameters:

idx Number
The index to retrieve.

Returns:

Object
the value or undefined if none found

objectsAt

(indexes) Array

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

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var arr = ['a', 'b', 'c', 'd'];

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

Parameters:

indexes Array
An array of indexes of items to return.

Returns:

Array

popObject

Pop object from array or nil if none are left. Works just like pop() but it is KVO-compliant.

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var colors = ["red", "green", "blue"];
colors.popObject();   // "blue"
console.log(colors);  // ["red", "green"]

Returns:

object

propertyDidChange

(keyName) Ember.Observable

Notify the observer system that a property has just changed.

Sometimes you need to change a value directly or indirectly without actually calling get() or set() on it. In this case, you can use this method and propertyWillChange() instead. Calling these two methods together will notify all observers that the property has potentially changed value.

Note that you must always call propertyWillChange and propertyDidChange as a pair. If you do not, it may get the property change groups out of order and cause notifications to be delivered more often than you would like.

Parameters:

keyName String
The property key that has just changed.

Returns:

Ember.Observable

propertyWillChange

(keyName) Ember.Observable

Notify the observer system that a property is about to change.

Sometimes you need to change a value directly or indirectly without actually calling get() or set() on it. In this case, you can use this method and propertyDidChange() instead. Calling these two methods together will notify all observers that the property has potentially changed value.

Note that you must always call propertyWillChange and propertyDidChange as a pair. If you do not, it may get the property change groups out of order and cause notifications to be delivered more often than you would like.

Parameters:

keyName String
The property key that is about to change.

Returns:

Ember.Observable

pushObject

(obj)

Push the object onto the end of the array. Works just like push() but it is KVO-compliant.

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var colors = ["red", "green"];
colors.pushObject("black");     // ["red", "green", "black"]
colors.pushObject(["yellow"]);  // ["red", "green", ["yellow"]]

Parameters:

obj *
object to push

Returns:

object same object passed as a param

pushObjects

(objects) Ember.Array

Add the objects in the passed numerable to the end of the array. Defers notifying observers of the change until all objects are added.

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var colors = ["red"];
colors.pushObjects(["yellow", "orange"]);  // ["red", "yellow", "orange"]

Parameters:

objects Ember.Enumerable
the objects to add

Returns:

Ember.Array
receiver

reduce

(callback, initialValue, reducerProperty) Object

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):

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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.

Parameters:

callback Function
The callback to execute
initialValue Object
Initial value for the reduce
reducerProperty String
internal use only.

Returns:

Object
The reduced value.

reject

(callback, target) Array

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

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

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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 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.

Parameters:

callback Function
The callback to execute
target [Object]
The target object to use

Returns:

Array
A rejected array.

rejectBy

(key, value) 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.

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Array
rejected array

rejectProperty

(key, value) Array deprecated

Use rejectBy instead

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.

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Array
rejected array

removeArrayObserver

(target, opts) Ember.Array

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.

Parameters:

target Object
The object observing the array.
opts Hash
Optional hash of configuration options including `willChange` and `didChange` option.

Returns:

Ember.Array
receiver

removeAt

(start, len) Ember.Array

Remove an object at the specified index using the replace() primitive method. You can pass either a single index, or a start and a length.

If you pass a start and length that is beyond the length this method will throw an OUT_OF_RANGE_EXCEPTION.

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var colors = ["red", "green", "blue", "yellow", "orange"];
colors.removeAt(0);     // ["green", "blue", "yellow", "orange"]
colors.removeAt(2, 2);  // ["green", "blue"]
colors.removeAt(4, 2);  // Error: Index out of range

Parameters:

start Number
index, start of range
len Number
length of passing range

Returns:

Ember.Array
receiver

removeEnumerableObserver

(target, opts)

Removes a registered enumerable observer.

Parameters:

target Object
opts [Hash]

Returns:

this

removeObject

(obj) Ember.Array

Remove all occurrences of an object in the array.

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var cities = ["Chicago", "Berlin", "Lima", "Chicago"];
cities.removeObject("Chicago");  // ["Berlin", "Lima"]
cities.removeObject("Lima");     // ["Berlin"]
cities.removeObject("Tokyo")     // ["Berlin"]

Parameters:

obj *
object to remove

Returns:

Ember.Array
receiver

removeObjects

(objects) Object

Removes each object in the passed enumerable from the receiver.

Parameters:

objects Ember.Enumerable
the objects to remove

Returns:

Object
receiver

removeObserver

(key, target, method)

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.

Parameters:

key String
The key to observer
target Object
The target object to invoke
method String|Function
The method to invoke.

reopen

Augments a constructor's prototype with additional properties and functions:

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MyObject = Ember.Object.extend({
  name: 'an object'
});

o = MyObject.create();
o.get('name'); // 'an object'

MyObject.reopen({
  say: function(msg){
    console.log(msg);
  }
})

o2 = MyObject.create();
o2.say("hello"); // logs "hello"

o.say("goodbye"); // logs "goodbye"

To add functions and properties to the constructor itself, see reopenClass

reopenClass

Augments a constructor's own properties and functions:

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MyObject = Ember.Object.extend({
  name: 'an object'
});

MyObject.reopenClass({
  canBuild: false
});

MyObject.canBuild; // false
o = MyObject.create();

In other words, this creates static properties and functions for the class. These are only available on the class and not on any instance of that class.

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App.Person = Ember.Object.extend({
  name : "",
  sayHello : function(){
    alert("Hello. My name is " + this.get('name'));
  }
});

App.Person.reopenClass({
  species : "Homo sapiens",
  createPerson: function(newPersonsName){
    return App.Person.create({
      name:newPersonsName
    });
  }
});

var tom = App.Person.create({
  name : "Tom Dale"
});
var yehuda = App.Person.createPerson("Yehuda Katz");

tom.sayHello(); // "Hello. My name is Tom Dale"
yehuda.sayHello(); // "Hello. My name is Yehuda Katz"
alert(App.Person.species); // "Homo sapiens"

Note that species and createPerson are not valid on the tom and yehuda variables. They are only valid on App.Person.

To add functions and properties to instances of a constructor by extending the constructor's prototype see reopen

replace

(idx, amt, objects)

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

This is one of the primitives you must implement to support Ember.Array. You should replace amt objects started at idx with the objects in the passed array. You should also call this.enumerableContentDidChange()

Parameters:

idx Number
Starting index in the array to replace. If idx >= length, then append to the end of the array.
amt Number
Number of elements that should be removed from the array, starting at *idx*.
objects Array
An array of zero or more objects that should be inserted into the array at *idx*

replaceContent

(idx, amt, objects) Void

Should actually replace the specified objects on the content array. You can override this method in subclasses to transform the content item into something new.

This method will only be called if content is non-null.

Parameters:

idx Number
The starting index
amt Number
The number of items to remove from the content.
objects Array
Optional array of objects to insert or null if no objects.

Returns:

Void

reverseObjects

Ember.Array

Reverse objects in the array. Works just like reverse() but it is KVO-compliant.

Returns:

Ember.Array
receiver

set

(keyName, value) Ember.Observable

Sets the provided key or path to the 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.

Chaining

In addition to property changes, set() returns the value of the object itself so you can do chaining like this:

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record.set('firstName', 'Charles').set('lastName', 'Jolley');

Parameters:

keyName String
The property to set
value Object
The value to set or `null`.

Returns:

Ember.Observable

setEach

(key, value) Object

Sets the value on the named property for each member. This is more efficient 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.

Parameters:

key String
The key to set
value Object
The object to set

Returns:

Object
receiver

setObjects

(objects) Ember.Array

Replace all the receiver's content with content of the argument. If argument is an empty array receiver will be cleared.

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var colors = ["red", "green", "blue"];
colors.setObjects(["black", "white"]);  // ["black", "white"]
colors.setObjects([]);                  // []

Parameters:

objects Ember.Array
array whose content will be used for replacing the content of the receiver

Returns:

Ember.Array
receiver with the new content

setProperties

(hash) Ember.Observable

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

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

Parameters:

hash Hash
the hash of keys and values to set

Returns:

Ember.Observable

shiftObject

Shift an object from start of array or nil if none are left. Works just like shift() but it is KVO-compliant.

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var colors = ["red", "green", "blue"];
colors.shiftObject();  // "red"
console.log(colors);   // ["green", "blue"]

Returns:

object

slice

(beginIndex, endIndex) Array

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.

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

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

Parameters:

beginIndex Integer
(Optional) index to begin slicing from.
endIndex Integer
(Optional) index to end the slice at (but not included).

Returns:

Array
New array with specified slice

some

(callback, target) Boolean deprecated

Use any instead

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

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

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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.

Usage Example:

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

Parameters:

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

someProperty

(key, value) Boolean deprecated

Use isAny instead

Parameters:

key String
the property to test
value [String]
optional value to test against.

Returns:

Boolean
`true` if the passed function returns `true` for any item

sortBy

(property) 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.

Parameters:

property String
name(s) to sort on

Returns:

Array
The sorted array.

toArray

Array

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

Returns:

Array
the enumerable as an array.

toString

String

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

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App.Person = Em.Object.extend()
person = App.Person.create()
person.toString() //=> "<App.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:

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

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

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

Returns:

String
string representation

toggleProperty

(keyName) Object

Set the value of a boolean property to the opposite of it's current value.

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starship.toggleProperty('warpDriveEngaged');

Parameters:

keyName String
The name of the property to toggle

Returns:

Object
The new property value

uniq

Ember.Enumerable

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

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

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

Returns:

Ember.Enumerable

unshiftObject

(obj)

Unshift an object to start of array. Works just like unshift() but it is KVO-compliant.

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var colors = ["red"];
colors.unshiftObject("yellow");    // ["yellow", "red"]
colors.unshiftObject(["black"]);   // [["black"], "yellow", "red"]

Parameters:

obj *
object to unshift

Returns:

object same object passed as a param

unshiftObjects

(objects) Ember.Array

Adds the named objects to the beginning of the array. Defers notifying observers until all objects have been added.

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var colors = ["red"];
colors.unshiftObjects(["black", "white"]);   // ["black", "white", "red"]
colors.unshiftObjects("yellow"); // Type Error: 'undefined' is not a function

Parameters:

objects Ember.Enumerable
the objects to add

Returns:

Ember.Array
receiver

willDestroy

Override to implement teardown.

willMergeMixin

private

Provides mixin-time validation for injected properties.

without

(value) Ember.Enumerable

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

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

Parameters:

value Object

Returns:

Ember.Enumerable
Show:

@each

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.

[]

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.

Returns:

this

arrangedContent

The array that the proxy pretends to be. In the default ArrayProxy implementation, this and content are the same. Subclasses of ArrayProxy can override this property to provide things like sorting and filtering.

concatenatedProperties

Array

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:

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App.BarView = Ember.View.extend({
  someNonConcatenatedProperty: ['bar'],
  classNames: ['bar']
});

App.FooBarView = App.BarView.extend({
  someNonConcatenatedProperty: ['foo'],
  classNames: ['foo']
});

var fooBarView = App.FooBarView.create();
fooBarView.get('someNonConcatenatedProperty'); // ['foo']
fooBarView.get('classNames'); // ['ember-view', 'bar', 'foo']

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

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var view = App.FooBarView.create({
  someNonConcatenatedProperty: ['baz'],
  classNames: ['baz']
})
view.get('someNonConcatenatedProperty'); // ['baz']
view.get('classNames'); // ['ember-view', 'bar', 'foo', 'baz']

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

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var view = App.FooBarView.create({
  classNames: 'baz'
})
view.get('classNames'); // ['ember-view', 'bar', 'foo', 'baz']

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

In Ember.View the classNameBindings and attributeBindings properties are also concatenated, in addition to classNames.

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).

Default: null

content

Ember.Array

The content array. Must be an object that implements Ember.Array and/or Ember.MutableArray.

firstObject

Object

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.

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

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

Returns:

Object
the object or undefined

hasArrayObservers

Boolean

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

hasEnumerableObservers

Boolean

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

isDestroyed

Destroyed object property flag.

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

Default: false

isDestroying

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.

Default: false

lastObject

Object

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.

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

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

Returns:

Object
the last object or undefined

length

Number

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