Angular 12 References/ Core
🍀 Angular References
Oleksa Novyk | GitHub

@ContentChild

You can use ContentChild to get the first element or the directive matching the selector from the content DOM. If the content DOM changes, and a new child matches the selector, the property will be updated.

Content queries are set before the ngAfterContentInit callback is called.

Example

import {AfterContentInit, ContentChild, Directive} from '@angular/core';
 
@Directive({selector: 'child-directive'})
class ChildDirective {
}
 
@Directive({selector: 'someDir'})
class SomeDir implements AfterContentInit {
  @ContentChild(ChildDirective, {static: true}) contentChild: ChildDirective;
 
  ngAfterContentInit() {
    // contentChild is set
  }
}

Options

@ContentChild(
  selector: Type<any>|Function|string, 
  opts?: {read?: any, static: boolean},
)

selector#

selector: Type<any>|Function|string

The directive type or the name used for querying.

Supported selectors include:

  • any class with the @Component or @Directive decorator
  • a template reference variable as a string (e.g. query <my-component #cmp></my-component> with @ViewChild('cmp'))
  • any provider defined in the child component tree of the current component (e.g. @ViewChild(SomeService) someService: SomeService)
  • any provider defined through a string token (e.g. @ViewChild('someToken') someTokenVal: any)
  • a TemplateRef (e.g. query <ng-template></ng-template> with @ViewChild(TemplateRef) template;)

opts#

opts?: {read?: any}

Additional options.

  • read - read a different token from the queried element.
  • static - true to resolve query results before change detection runs, false to resolve after change detection.
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