Class Ember.NativeArray
publicUses: | Observable , | MutableArray
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Defined in: | packages/@ember/-internals/runtime/lib/mixins/array.js:1948 |
Module: | ember |
addArrayObserver (target, opts) EmberArray public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:483
- target
- Object
- The observer object.
- opts
- Object
- Optional hash of configuration options including `willChange` and `didChange` option.
- returns
- EmberArray
- receiver
Adds an array observer to the receiving array. The array observer object normally must implement two methods:
-
willChange(observedObj, start, removeCount, addCount)
- This method will be called just before the array is modified. -
didChange(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.
addObject (obj) EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1864
- obj
- *
- object to add, if not already present
- returns
- EmberArray
- receiver
Push the object onto the end of the array if it is not already present in the array.
let cities = ['Chicago', 'Berlin']; cities.addObject('Lima'); // ['Chicago', 'Berlin', 'Lima'] cities.addObject('Berlin'); // ['Chicago', 'Berlin', 'Lima']
addObjects (objects) EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1890
- objects
- EmberArray
- the objects to add.
- returns
- EmberArray
- receiver
Adds each object in the passed array to the receiver.
addObserver (key, target, method, sync) Observable public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:286
- key
- String
- The key to observe
- target
- Object
- The target object to invoke
- method
- String|Function
- The method to invoke
- sync
- Boolean
- Whether the observer is sync or not
- returns
- Observable
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.
There are two common invocation patterns for .addObserver()
:
- Passing two arguments:
- the name of the property to observe (as a string)
- the function to invoke (an actual function)
- Passing three arguments:
- the name of the property to observe (as a string)
- the target object (will be used to look up and invoke a function on)
- the name of the function to invoke on the target object (as a string).
component.js
import Component from '@ember/component'; export default Component.extend({ init() { this._super(...arguments); // the following are equivalent: // using three arguments this.addObserver('foo', this, 'fooDidChange'); // using two arguments this.addObserver('foo', (...args) => { this.fooDidChange(...args); }); }, fooDidChange() { // your custom logic code } });
Observer Methods
Observer methods have the following signature:
component.js
import Component from '@ember/component'; export default Component.extend({ init() { this._super(...arguments); this.addObserver('foo', this, 'fooDidChange'); }, fooDidChange(sender, key, value, rev) { // your code } });
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.
Usually you will not need the value 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.
any (callback, target) Boolean public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1179
- 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
The any() method executes the callback function once for each element present in the array until it finds the one where callback returns a truthy value (i.e. true
). If such an element is found, any() immediately returns true. Otherwise, any() returns false.
function(item, index, array);
-
item
is the current item in the iteration. -
index
is the current index in the iteration. -
array
is the array 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. It can be a good way to give your iterator function access to an object in cases where an ES6 arrow function would not be appropriate.
Usage Example:
let includesManager = people.any(this.findPersonInManagersList, this); let includesStockHolder = people.any(person => { return this.findPersonInStockHoldersList(person) }); if (includesManager || includesStockHolder) { Paychecks.addBiggerBonus(); }
arrayContentDidChange (startIdx, removeAmt, addAmt) EmberArray public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:646
- 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.
let arr = [1, 2, 3, 4, 5]; arr.copyWithin(-2); // [1, 2, 3, 1, 2] // arr.lastObject = 5 arr.arrayContentDidChange(3, 2, 2); // arr.lastObject = 2
arrayContentWillChange (startIdx, removeAmt, addAmt) EmberArray public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:579
- 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.
post.js
import Component from '@ember/component'; import EmberObject from '@ember/object'; const Post = EmberObject.extend({ body: '', save() {} }) export default Component.extend({ attemptsToModify: 0, successfulModifications: 0, posts: null, init() { this._super(...arguments); this.posts = [1, 2, 3].map(i => Post.create({ body: i })); this.posts.addArrayObserver(this, { willChange() { this.incrementProperty('attemptsToModify'); }, didChange() { this.incrementProperty('successfulModifications'); } }); }, actions: { editPost(post, newContent) { let oldContent = post.body, postIndex = this.posts.indexOf(post); this.posts.arrayContentWillChange(postIndex, 0, 0); // attemptsToModify = 1 post.set('body', newContent); post.save() .then(response => { this.posts.arrayContentDidChange(postIndex, 0, 0); // successfulModifications = 1 }) .catch(error => { post.set('body', oldContent); }) } } });
cacheFor (keyName) Object public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:487
- keyName
- String
- returns
- Object
- The cached value of the computed property, if any
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.
clear Array public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1568
- returns
- Array
- An empty Array.
Remove all elements from the array. This is useful if you want to reuse an existing array without having to recreate it.
let colors = ['red', 'green', 'blue']; colors.length; // 3 colors.clear(); // [] colors.length; // 0
compact Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1367
- 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']
decrementProperty (keyName, decrement) Number public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:448
- 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
Set the value of a property to the current value minus some amount.
player.decrementProperty('lives'); orc.decrementProperty('health', 5);
every (callback, target) Boolean public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1095
- 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 Array.prototype.every()
method defined in ES5.
The callback method should have the following signature:
function(item, index, array);
-
item
is the current item in the iteration. -
index
is the current index in the iteration. -
array
is the array itself.
All params are optional. The method should return 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.
Usage example:
function isAdult(person) { return person.age > 18; }; const people = Ember.A([{ name: 'John', age: 24 }, { name: 'Joan', age: 45 }]); const areAllAdults = people.every(isAdult);
filter (callback, target) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:845
- callback
- Function
- The callback to execute
- target
- Object
- The target object to use
- returns
- Array
- A filtered array.
Returns a new array with all of the items in the enumeration that the provided callback function returns true for. This method corresponds to Array.prototype.filter().
The callback method should have the following signature:
function(item, index, array);
-
item
is the current item in the iteration. -
index
is the current index in the iteration. -
array
is the array itself.
All parameters are optional. The function should return true
to include the item in the results, and false
otherwise.
Example:
function isAdult(person) { return person.age > 18; }; let people = Ember.A([{ name: 'John', age: 14 }, { name: 'Joan', age: 45 }]); people.filter(isAdult); // returns [{ name: 'Joan', age: 45 }];
Note that in addition to a callback, you can 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. For example:
function isAdultAndEngineer(person) { return person.age > 18 && this.engineering; } class AdultsCollection { engineering = false; constructor(opts = {}) { super(...arguments); this.engineering = opts.engineering; this.people = Ember.A([{ name: 'John', age: 14 }, { name: 'Joan', age: 45 }]); } } let collection = new AdultsCollection({ engineering: true }); collection.people.filter(isAdultAndEngineer, { target: collection });
filterBy (key, value) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:965
- key
- String
- the property to test
- value
- *
- optional value to test against.
- returns
- Array
- filtered array
Filters the array by the property and an optional value. If a value is given, it returns the items that have said value for the property. If not, it returns all the items that have a truthy value for the property.
Example Usage:
let things = Ember.A([{ food: 'apple', isFruit: true }, { food: 'beans', isFruit: false }]); things.filterBy('food', 'beans'); // [{ food: 'beans', isFruit: false }] things.filterBy('isFruit'); // [{ food: 'apple', isFruit: true }]
find (callback, target) Object public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1016
- 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 is similar to the find()
method defined in ECMAScript 2015.
The callback method you provide should have the following signature (all parameters are optional):
function(item, index, array);
-
item
is the current item in the iteration. -
index
is the current index in the iteration. -
array
is the array 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.
Example Usage:
let users = [ { id: 1, name: 'Yehuda' }, { id: 2, name: 'Tom' }, { id: 3, name: 'Melanie' }, { id: 4, name: 'Leah' } ]; users.find((user) => user.name == 'Tom'); // [{ id: 2, name: 'Tom' }] users.find(({ id }) => id == 3); // [{ id: 3, name: 'Melanie' }]
findBy (key, value) Object public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1063
- 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.
Usage Example:
let users = [ { id: 1, name: 'Yehuda', isTom: false }, { id: 2, name: 'Tom', isTom: true }, { id: 3, name: 'Melanie', isTom: false }, { id: 4, name: 'Leah', isTom: false } ]; users.findBy('id', 4); // { id: 4, name: 'Leah', isTom: false } users.findBy('name', 'Melanie'); // { id: 3, name: 'Melanie', isTom: false } users.findBy('isTom'); // { id: 2, name: 'Tom', isTom: true }
forEach (callback, target) Object public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:674
- callback
- Function
- The callback to execute
- target
- Object
- The target object to use
- returns
- Object
- receiver
Iterates through the array, 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, array);
-
item
is the current item in the iteration. -
index
is the current index in the iteration. -
array
is the array 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.
Example Usage:
let foods = [ { name: 'apple', eaten: false }, { name: 'banana', eaten: false }, { name: 'carrot', eaten: false } ]; foods.forEach((food) => food.eaten = true); let output = ''; foods.forEach((item, index, array) => output += `${index + 1}/${array.length} ${item.name}\n`; ); console.log(output); // 1/3 apple // 2/3 banana // 3/3 carrot
get (keyName) Object public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:93
- keyName
- String
- The property to retrieve
- returns
- Object
- The property value or undefined.
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:
import { computed } from '@ember/object'; fullName: computed('firstName', 'lastName', function() { return this.get('firstName') + ' ' + this.get('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.
getEach (key) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:734
- key
- String
- name of the property
- returns
- Array
- The mapped array.
Alias for mapBy
.
Returns the value of the named property on all items in the enumeration.
let people = [{name: 'Joe'}, {name: 'Matt'}]; people.getEach('name'); // ['Joe', 'Matt']; people.getEach('nonexistentProperty'); // [undefined, undefined];
getProperties (list) Object public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:138
- list
- String...|Array
- of keys to get
- returns
- Object
To get the values of multiple properties at once, call getProperties
with a list of strings or an array:
record.getProperties('firstName', 'lastName', 'zipCode'); // { firstName: 'John', lastName: 'Doe', zipCode: '10011' }
is equivalent to:
record.getProperties(['firstName', 'lastName', 'zipCode']); // { firstName: 'John', lastName: 'Doe', zipCode: '10011' }
includes (object, startAt) Boolean public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1383
- object
- 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.
Used to determine if the array contains the passed object. Returns true
if found, false
otherwise.
The optional startAt
argument can be used to pass a starting index to search from, effectively slicing the searchable portion of the array. If it's negative it will add the array length to the startAt value passed in as the index to search from. If less than or equal to -1 * array.length
the entire array is searched.
This method has the same behavior of JavaScript's Array.includes.
[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
incrementProperty (keyName, increment) Number public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:426
- 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
Set the value of a property to the current value plus some amount.
person.incrementProperty('age'); team.incrementProperty('score', 2);
indexOf (object, startAt) Number public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:383
- object
- Object
- the item to search for
- startAt
- Number
- optional starting location to search, default 0
- returns
- Number
- index or -1 if not found
Used to determine the passed object's first occurrence in the array. Returns the index if found, -1 if no match is found.
The optional startAt
argument can be used to pass a starting index to search from, effectively slicing the searchable portion of the array. If it's negative it will add the array length to the startAt value passed in as the index to search from. If less than or equal to -1 * array.length
the entire array is searched.
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, equivalent to indexOf('a', 4) arr.indexOf('a', -100); // 0, searches entire array arr.indexOf('b', 3); // -1 arr.indexOf('a', 100); // -1 let people = [{ name: 'Zoey' }, { name: 'Bob' }] let newPerson = { name: 'Tom' }; people = [newPerson, ...people, newPerson]; people.indexOf(newPerson); // 0 people.indexOf(newPerson, 1); // 3 people.indexOf(newPerson, -4); // 0 people.indexOf(newPerson, 10); // -1
insertAt (idx, object) EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1594
- idx
- Number
- index of insert the object at.
- object
- Object
- object to insert
- returns
- EmberArray
- receiver
This will use the primitive replace()
method to insert an object at the specified index.
let colors = ['red', 'green', 'blue']; colors.insertAt(2, 'yellow'); // ['red', 'green', 'yellow', 'blue'] colors.insertAt(5, 'orange'); // Error: Index out of range
invoke (methodName, args) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1317
- 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.
class Person { name = null; constructor(name) { this.name = name; } greet(prefix='Hello') { return `${prefix} ${this.name}`; } } let people = [new Person('Joe'), new Person('Matt')]; people.invoke('greet'); // ['Hello Joe', 'Hello Matt'] people.invoke('greet', 'Bonjour'); // ['Bonjour Joe', 'Bonjour Matt']
isAny (key, value) Boolean public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1223
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 array. This method is often simpler/faster than using a callback.
Example usage:
const food = [ { food: 'apple', isFruit: true }, { food: 'bread', isFruit: false }, { food: 'banana', isFruit: true } ]; food.isAny('isFruit'); // true
isEvery (key, value) Boolean public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1137
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 array. 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 array.
class Language { constructor(name, isProgrammingLanguage) { this.name = name; this.programmingLanguage = isProgrammingLanguage; } } const compiledLanguages = [ new Language('Java', true), new Language('Go', true), new Language('Rust', true) ] const languagesKnownByMe = [ new Language('Javascript', true), new Language('English', false), new Language('Ruby', true) ] compiledLanguages.isEvery('programmingLanguage'); // true languagesKnownByMe.isEvery('programmingLanguage'); // false
lastIndexOf (object, startAt) Number public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:425
- object
- Object
- the item to search for
- startAt
- Number
- optional starting location to search from backwards, defaults to `(array.length - 1)`
- returns
- Number
- The last index of the `object` in the array 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 greater than or equal to the length of the array, the search starts from the last position.
- If it's negative, it is taken as the offset from the end of the array i.e.
startAt + array.length
. - If it's any other positive number, will search backwards from that index 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('a', -3); // 0 arr.lastIndexOf('b', 3); // 1 arr.lastIndexOf('a', 100); // 4
map (callback, target) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:780
- 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, array); let arr = [1, 2, 3, 4, 5, 6]; arr.map(element => element * element); // [1, 4, 9, 16, 25, 36]; arr.map((element, index) => element + index); // [1, 3, 5, 7, 9, 11];
-
item
is the current item in the iteration. -
index
is the current index in the iteration. -
array
is the array itself.
It should return the mapped value.
Note that in addition to a callback, you can also pass an optional target object that will be set as this
on the context. This is a good way to give your iterator function access to the current object.
mapBy (key) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:824
- 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.
let people = [{name: 'Joe'}, {name: 'Matt'}]; people.mapBy('name'); // ['Joe', 'Matt']; people.mapBy('unknownProperty'); // [undefined, undefined];
notifyPropertyChange (keyName) Observable public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:268
- keyName
- String
- The property key to be notified about.
- returns
- 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 instead. Calling this method will notify all observers that the property has potentially changed value.
objectAt (idx) * public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:234
- idx
- Number
- The index of the item to return.
- returns
- *
- item at index or undefined
Returns the object at the given index
. If the given index
is negative or is greater or equal than the array length, returns undefined
.
This is one of the primitives you must implement to support EmberArray
. If your object supports retrieving the value of an array item using get()
(i.e. myArray.get(0)
), then you do not need to implement this method yourself.
let arr = ['a', 'b', 'c', 'd']; arr.objectAt(0); // 'a' arr.objectAt(3); // 'd' arr.objectAt(-1); // undefined arr.objectAt(4); // undefined arr.objectAt(5); // undefined
objectsAt (indexes) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:259
- 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]
popObject public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1681
- returns
- object
Pop object from array or nil if none are left. Works just like pop()
but it is KVO-compliant.
let colors = ['red', 'green', 'blue']; colors.popObject(); // 'blue' console.log(colors); // ['red', 'green']
pushObject (obj) public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1641
- obj
- *
- object to push
- returns
- object same object passed as a param
Push the object onto the end of the array. Works just like push()
but it is KVO-compliant.
let colors = ['red', 'green']; colors.pushObject('black'); // ['red', 'green', 'black'] colors.pushObject(['yellow']); // ['red', 'green', ['yellow']]
pushObjects (objects) EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1661
- objects
- EmberArray
- the objects to add
- returns
- EmberArray
- receiver
Add the objects in the passed array to the end of the array. Defers notifying observers of the change until all objects are added.
let colors = ['red']; colors.pushObjects(['yellow', 'orange']); // ['red', 'yellow', 'orange']
reduce (callback, initialValue) Object public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1251
- callback
- Function
- The callback to execute
- initialValue
- Object
- Initial value for the reduce
- returns
- Object
- The reduced value.
This will combine the values of the array into a single value. It is a useful way to collect a summary value from an array. 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, array);
-
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. -
array
is the array 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.
Example Usage:
let numbers = [1, 2, 3, 4, 5]; numbers.reduce(function(summation, current) { return summation + current; }); // 15 (1 + 2 + 3 + 4 + 5) numbers.reduce(function(summation, current) { return summation + current; }, -15); // 0 (-15 + 1 + 2 + 3 + 4 + 5) let binaryValues = [true, false, false]; binaryValues.reduce(function(truthValue, current) { return truthValue && current; }); // false (true && false && false)
reject (callback, target) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:918
- 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, array);
- item is the current item in the iteration.
- index is the current index in the iteration
- array is the array 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.
Example Usage:
const food = [ { food: 'apple', isFruit: true }, { food: 'bread', isFruit: false }, { food: 'banana', isFruit: true } ]; const nonFruits = food.reject(function(thing) { return thing.isFruit; }); // [{food: 'bread', isFruit: false}]
rejectBy (key, value) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:989
- key
- String
- the property to test
- value
- *
- optional value to test against.
- returns
- Array
- rejected array
Returns an array with the items that do not have truthy values for the provided key. You can pass an optional second argument with a target value to reject for the key. Otherwise this will reject objects where the provided property evaluates to false.
Example Usage:
let food = [ { name: "apple", isFruit: true }, { name: "carrot", isFruit: false }, { name: "bread", isFruit: false }, ]; food.rejectBy('isFruit'); // [{ name: "carrot", isFruit: false }, { name: "bread", isFruit: false }] food.rejectBy('name', 'carrot'); // [{ name: "apple", isFruit: true }}, { name: "bread", isFruit: false }]
removeArrayObserver (target, opts) EmberArray public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:536
- target
- Object
- The object observing the array.
- opts
- Object
- Optional hash of configuration options including `willChange` and `didChange` option.
- returns
- EmberArray
- receiver
Removes an array observer from the object if the observer is current registered. Calling this method multiple times with the same object will have no effect.
removeAt (start, len) EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1616
- start
- Number
- index, start of range
- len
- Number
- length of passing range
- returns
- EmberArray
- receiver
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 assertion.
let 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
removeObject (obj) EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1819
- obj
- *
- object to remove
- returns
- EmberArray
- receiver
Remove all occurrences of an object in the array.
let cities = ['Chicago', 'Berlin', 'Lima', 'Chicago']; cities.removeObject('Chicago'); // ['Berlin', 'Lima'] cities.removeObject('Lima'); // ['Berlin'] cities.removeObject('Tokyo') // ['Berlin']
removeObjects (objects) EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1847
- objects
- EmberArray
- the objects to remove
- returns
- EmberArray
- receiver
Removes each object in the passed array from the receiver.
removeObserver (key, target, method, sync) Observable public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:374
- key
- String
- The key to observe
- target
- Object
- The target object to invoke
- method
- String|Function
- The method to invoke
- sync
- Boolean
- Whether the observer is async or not
- returns
- Observable
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.
replace (idx, amt, objects) public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1549
- 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
- EmberArray
- An array of zero or more objects that should be inserted into the array at *idx*
Required. You must implement this method to apply this mixin.
This is one of the primitives you must implement to support Array
. You should replace amt objects started at idx with the objects in the passed array. You should also call this.arrayContentDidChange()
Note that this method is expected to validate the type(s) of objects that it expects.
reverseObjects EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1773
- returns
- EmberArray
- receiver
Reverse objects in the array. Works just like reverse()
but it is KVO-compliant.
set (keyName, value) Object public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:163
- keyName
- String
- The property to set
- value
- Object
- The value to set or `null`.
- returns
- Object
- The passed value
Sets the provided key or path to the value.
record.set("key", 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.
setEach (key, value) Object public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:757
- 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 Observable, the value will be changed to set(),
otherwise it will be set directly. null
objects are skipped.
let people = [{name: 'Joe'}, {name: 'Matt'}]; people.setEach('zipCode', '10011'); // [{name: 'Joe', zipCode: '10011'}, {name: 'Matt', zipCode: '10011'}];
setObjects (objects) EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1792
- objects
- EmberArray
- array whose content will be used for replacing the content of the receiver
- returns
- EmberArray
- receiver with the new content
Replace all the receiver's content with content of the argument. If argument is an empty array receiver will be cleared.
let colors = ['red', 'green', 'blue']; colors.setObjects(['black', 'white']); // ['black', 'white'] colors.setObjects([]); // []
setProperties (hash) Object public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:211
- hash
- Object
- the hash of keys and values to set
- returns
- Object
- The passed in hash
Sets a list of properties at once. These properties are set inside a single beginPropertyChanges
and endPropertyChanges
batch, so observers will be buffered.
record.setProperties({ firstName: 'Charles', lastName: 'Jolley' });
shiftObject public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1707
- returns
- object
Shift an object from start of array or nil if none are left. Works just like shift()
but it is KVO-compliant.
let colors = ['red', 'green', 'blue']; colors.shiftObject(); // 'red' console.log(colors); // ['green', 'blue']
slice (beginIndex, endIndex) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:343
- beginIndex
- Number
- (Optional) index to begin slicing from.
- endIndex
- Number
- (Optional) index to end the slice at (but not included).
- returns
- Array
- New array with specified slice
Returns a new array that is a slice of the receiver. This implementation uses the observable array methods to retrieve the objects for the new slice.
let arr = ['red', 'green', 'blue']; arr.slice(0); // ['red', 'green', 'blue'] arr.slice(0, 2); // ['red', 'green'] arr.slice(1, 100); // ['green', 'blue']
sortBy (property) Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1416
Available since v1.2.0
- property
- String
- name(s) to sort on
- returns
- Array
- The sorted array.
Sorts the array by the keys specified in the argument.
You may provide multiple arguments to sort by multiple properties.
let colors = [ { name: 'red', weight: 500 }, { name: 'green', weight: 600 }, { name: 'blue', weight: 500 } ]; colors.sortBy('name'); // [{name: 'blue', weight: 500}, {name: 'green', weight: 600}, {name: 'red', weight: 500}] colors.sortBy('weight', 'name'); // [{name: 'blue', weight: 500}, {name: 'red', weight: 500}, {name: 'green', weight: 600}]
toArray Array public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1355
- returns
- Array
- the object as an array.
Simply converts the object into a genuine array. The order is not guaranteed. Corresponds to the method implemented by Prototype.
toggleProperty (keyName) Boolean public
Module: | ember |
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Inherited from Observable packages/@ember/-internals/runtime/lib/mixins/observable.js:470
- keyName
- String
- The name of the property to toggle
- returns
- Boolean
- The new property value
Set the value of a boolean property to the opposite of its current value.
starship.toggleProperty('warpDriveEngaged');
uniq EmberArray public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1460
- returns
- EmberArray
Returns a new array 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 (key) EmberArray public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1479
- key
- String,Function
- returns
- EmberArray
Returns a new array 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' }] let arr = [2.2, 2.1, 3.2, 3.3]; arr.uniqBy(Math.floor); // [2.2, 3.2];
unshiftObject (obj) public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1732
- obj
- *
- object to unshift
- returns
- object same object passed as a param
Unshift an object to start of array. Works just like unshift()
but it is KVO-compliant.
let colors = ['red']; colors.unshiftObject('yellow'); // ['yellow', 'red'] colors.unshiftObject(['black']); // [['black'], 'yellow', 'red']
unshiftObjects (objects) EmberArray public
Module: | ember |
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Inherited from MutableArray packages/@ember/-internals/runtime/lib/mixins/array.js:1752
- objects
- Enumberable
- the objects to add
- returns
- EmberArray
- receiver
Adds the named objects to the beginning of the array. Defers notifying observers until all objects have been added.
let colors = ['red']; colors.unshiftObjects(['black', 'white']); // ['black', 'white', 'red'] colors.unshiftObjects('yellow'); // Type Error: 'undefined' is not a function
without (value) EmberArray public
Module: | ember |
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Inherited from EmberArray packages/@ember/-internals/runtime/lib/mixins/array.js:1501
- value
- Object
- returns
- EmberArray
Returns a new array 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 array.
let arr = ['a', 'b', 'a', 'c']; arr.without('a'); // ['b', 'c']
© 2020 Yehuda Katz, Tom Dale and Ember.js contributors
Licensed under the MIT License.
https://api.emberjs.com/ember/3.25/classes/Ember.NativeArray/methods