@ViewChild

Property decorator that configures a view query. The change detector looks for the first element or the directive matching the selector in the view DOM. If the view DOM changes, and a new child matches the selector, the property is updated.

View queries are set before the ngAfterViewInit callback is called.

Example

import {AfterViewInit, Component, Directive, ViewChild} from '@angular/core';
 
@Directive({selector: 'child-directive'})
class ChildDirective {
}
 
@Component({selector: 'someCmp', templateUrl: 'someCmp.html'})
class SomeCmp implements AfterViewInit {
  @ViewChild(ChildDirective, {static: true}) child: ChildDirective;
 
  ngAfterViewInit() {
    // child is set
  }
}

Links & Tutorials

Options

@ViewChild(
  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 elements.
static - true to resolve query results before change detection runs.