Class EmberArray
publicimport 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.
addArrayObserver (target, opts) EmberArray public
Defined in packages/ember-runtime/lib/mixins/array.js:453
- target
- Object
The observer object.
- opts
- Object
Optional hash of configuration options including
willChange
anddidChange
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
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 returnstrue
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
anddidChange
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
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
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
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
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
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
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
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']