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.
addArrayObserver (target, opts) Ember.Array
Defined in packages/ember-runtime/lib/mixins/array.js:240
- target
- Object
- The observer object.
- opts
- Hash
- Optional hash of configuration options including `willChange` and `didChange` option.
- returns
- Ember.Array
- 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 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.
addEnumerableObserver (target, opts)
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:838
- target
- Object
- opts
- Hash
- returns
- this
Registers an enumerable observer. Must implement Ember.EnumerableObserver
mixin.
any (callback, target) Boolean
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:578
- 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. This corresponds with the some()
method in JavaScript 1.6.
The callback method you provide should have the following signature (all parameters are optional):
1 |
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:
1 |
if (people.any(isManager)) { Paychecks.addBiggerBonus(); } |
anyBy (key, value) Boolean
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:653
- 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
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.
arrayContentDidChange (startIdx, removeAmt, addAmt) Ember.Array
Defined in packages/ember-runtime/lib/mixins/array.js:353
- 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
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.
arrayContentWillChange (startIdx, removeAmt, addAmt) Ember.Array
Defined in packages/ember-runtime/lib/mixins/array.js:309
- 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
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.
compact Array
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:760
- returns
- Array
- the array without null and undefined elements.
Returns a copy of the array with all null and undefined elements removed.
1 2 |
var arr = ["a", null, "c", undefined]; arr.compact(); // ["a", "c"] |
contains (obj) Boolean
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:168
- obj
- Object
- The object to search for.
- returns
- Boolean
- `true` if object is found in enumerable.
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.
1 2 3 |
var arr = ["a", "b", "c"]; arr.contains("a"); // true arr.contains("z"); // false |
enumerableContentDidChange (start, removing, adding)
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:927
- start
- Number
- optional start offset for the content change. For unordered enumerables, you should always pass -1.
- 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.
Invoke this method when the contents of your enumerable has changed. This will notify any observers watching for content changes. If your 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.
enumerableContentWillChange (removing, adding)
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:891
- 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.
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.
every (callback, target) Boolean
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:515
- 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):
1 |
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:
1 |
if (people.every(isEngineer)) { Paychecks.addBigBonus(); } |
everyBy (key, value) Boolean
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:553
- key
- String
- the property to test
- value
- String
- optional value to test against.
- returns
- 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.
filter (callback, target) Array
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:316
- 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):
1 |
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.
filterBy (key, value) Array
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:382
- key
- String
- the property to test
- value
- String
- 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
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:440
- 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):
1 |
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
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:484
- 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
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:187
- 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):
1 |
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
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:228
- key
- String
- name of the property
- returns
- Array
- The mapped array.
Alias for mapBy
indexOf (object, startAt) Number
Defined in packages/ember-runtime/lib/mixins/array.js:170
- 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.
1 2 3 4 5 6 7 |
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 |
invoke (methodName, args) Array
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:723
- 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.
lastIndexOf (object, startAt) Number
Defined in packages/ember-runtime/lib/mixins/array.js:203
- 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.
1 2 3 4 5 6 7 |
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 |
map (callback, target) Array
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:256
- 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):
1 |
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
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:290
- 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.
nextObject (index, previousObject, context) Object
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:74
- 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
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.
objectAt (idx) *
Defined in packages/ember-runtime/lib/mixins/array.js:59
- 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 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.
1 2 3 4 5 6 |
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 |
objectsAt (indexes) Array
Defined in packages/ember-runtime/lib/mixins/array.js:86
- indexes
- Array
- An array of indexes of items to return.
- returns
- Array
This returns the objects at the specified indexes, using objectAt
.
1 2 3 |
var 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
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:678
- 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):
1 |
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
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:352
- 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 for. This method is the inverse of filter().
The callback method you provide should have the following signature (all parameters are optional):
1 |
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.
rejectBy (key, value) Array
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:409
- 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) Ember.Array
Defined in packages/ember-runtime/lib/mixins/array.js:276
- target
- Object
- The object observing the array.
- opts
- Hash
- Optional hash of configuration options including `willChange` and `didChange` option.
- returns
- Ember.Array
- 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.
removeEnumerableObserver (target, opts)
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:859
- target
- Object
- opts
- Hash
- returns
- this
Removes a registered enumerable observer.
setEach (key, value) Object
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:239
- 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
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.
slice (beginIndex, endIndex) Array
Defined in packages/ember-runtime/lib/mixins/array.js:138
- beginIndex
- Integer
- (Optional) index to begin slicing from.
- endIndex
- Integer
- (Optional) index to end the slice at.
- 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.
1 2 3 4 |
var arr = ['red', 'green', 'blue']; arr.slice(0); // ['red', 'green', 'blue'] arr.slice(0, 2); // ['red', 'green'] arr.slice(1, 100); // ['green', 'blue'] |
toArray Array
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:747
- 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
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:798
- returns
- Ember.Enumerable
Returns a new enumerable that contains only unique values. The default implementation returns an array regardless of the receiver type.
1 2 |
var arr = ["a", "a", "b", "b"]; arr.uniq(); // ["a", "b"] |
without (value) Ember.Enumerable
Inherited from Ember.Enumerable packages/ember-runtime/lib/mixins/enumerable.js:775
- 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 unless the receiver does not contain the value.
1 2 |
var arr = ["a", "b", "a", "c"]; arr.without("a"); // ["b", "c"] |