class
An unmodifiable list of items that Angular keeps up to date when the state of the application changes.
class QueryList<T> implements Iterable { constructor(_emitDistinctChangesOnly: boolean = false) dirty: true length: number first: T last: T changes: Observable<any> __@iterator: () => Iterator<T> get(index: number): T | undefined map<U>(fn: (item: T, index: number, array: T[]) => U): U[] filter(fn: (item: T, index: number, array: T[]) => boolean): T[] find(fn: (item: T, index: number, array: T[]) => boolean): T | undefined reduce<U>(fn: (prevValue: U, curValue: T, curIndex: number, array: T[]) => U, init: U): U forEach(fn: (item: T, index: number, array: T[]) => void): void some(fn: (value: T, index: number, array: T[]) => boolean): boolean toArray(): T[] toString(): string reset(resultsTree: (any[] | T)[], identityAccessor?: (value: T) => unknown): void notifyOnChanges(): void setDirty() destroy(): void }
The type of object that ViewChildren
, ContentChildren
, and QueryList
provide.
Implements an iterable interface, therefore it can be used in both ES6 javascript for (var i of items)
loops as well as in Angular templates with *ngFor="let i of myList"
.
Changes can be observed by subscribing to the changes Observable
.
NOTE: In the future this class will implement an Observable
interface.
Further information available in the Usage Notes...
|
_emitDistinctChangesOnly | boolean | Optional. Default is |
Property | Description |
---|---|
dirty: true | Read-Only |
length: number | Read-Only |
first: T | Read-Only |
last: T | Read-Only |
changes: Observable<any> |
Read-Only Returns |
__@iterator: () => Iterator<T> |
get() |
---|
Returns the QueryList entry at |
map() | |||
---|---|---|---|
See Array.map | |||
|
fn | (item: T, index: number, array: T[]) => U |
U[]
filter() | |||
---|---|---|---|
See Array.filter | |||
|
fn | (item: T, index: number, array: T[]) => boolean |
T[]
find() | |||
---|---|---|---|
See Array.find | |||
|
fn | (item: T, index: number, array: T[]) => boolean |
T | undefined
reduce() | ||||||
---|---|---|---|---|---|---|
See Array.reduce | ||||||
|
fn | (prevValue: U, curValue: T, curIndex: number, array: T[]) => U | |
init | U |
U
forEach() | |||
---|---|---|---|
See Array.forEach | |||
|
fn | (item: T, index: number, array: T[]) => void |
void
some() | |||
---|---|---|---|
See Array.some | |||
|
fn | (value: T, index: number, array: T[]) => boolean |
boolean
toArray() |
---|
Returns a copy of the internal results list as an Array. |
|
toString() |
---|
|
reset() | ||||||
---|---|---|---|---|---|---|
Updates the stored data of the query list, and resets the | ||||||
|
resultsTree | (any[] | T)[] | The query results to store |
identityAccessor | (value: T) => unknown | Optional function for extracting stable object identity from a value in the array. This function is executed for each element of the query result list while comparing current query list with the new one (provided as a first argument of the Optional. Default is |
void
notifyOnChanges() |
---|
Triggers a change event by emitting on the |
|
setDirty() |
---|
internal |
|
destroy() |
---|
internal |
|
@Component({...}) class Container { @ViewChildren(Item) items:QueryList<Item>; }
© 2010–2021 Google, Inc.
Licensed under the Creative Commons Attribution License 4.0.
https://v11.angular.io/api/core/QueryList