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API > @angular/core

ApplicationRef

A reference to an Angular application running on a page.

      
      interface ApplicationRef {
  componentTypes: Type<any>[]
  components: ComponentRef<any>[]
  isStable: Observable<boolean>
  viewCount
  bootstrap<C>(componentOrFactory: ComponentFactory<C> | Type<C>, rootSelectorOrNode?: string | any): ComponentRef<C>
  tick(): void
  attachView(viewRef: ViewRef): void
  detachView(viewRef: ViewRef): void
}

Properties

Property Description
componentTypes: Type<any>[] Read-only.

Get a list of component types registered to this application. This list is populated even before the component is created.
components: ComponentRef<any>[] Read-only.

Get a list of components registered to this application.
isStable: Observable<boolean> Read-only.

Returns an Observable that indicates when the application is stable or unstable.
viewCount Read-only.

Returns the number of attached views.

Methods

bootstrap()

Bootstrap a new component at the root level of the application.
bootstrap<C>(componentOrFactory: ComponentFactory<C> | Type<C>, rootSelectorOrNode?: string | any): ComponentRef<C>
      
      bootstrap<C>(componentOrFactory: ComponentFactory<C> | Type<C>, rootSelectorOrNode?: string | any): ComponentRef<C>

Parameters

componentOrFactory

Type: ComponentFactory | Type.
rootSelectorOrNode

Type: string | any.

Optional. Default is undefined.

Returns

ComponentRef<C>

Bootstrap process

When bootstrapping a new root component into an application, Angular mounts the specified application component onto DOM elements identified by the componentType's selector and kicks off automatic change detection to finish initializing the component.

Optionally, a component can be mounted onto a DOM element that does not match the componentType's selector.

Example

@Component({selector: 'my-app', template: 'Hello World'}) class MyApp { } const myPlatformFactory = createPlatformFactory(platformBrowserDynamic, 'myPlatform'); myPlatformFactory().bootstrapModule(MyApp); 
      
      @Component({selector: 'my-app', template: 'Hello World'})
class MyApp {
}

const myPlatformFactory = createPlatformFactory(platformBrowserDynamic, 'myPlatform');
myPlatformFactory().bootstrapModule(MyApp);

tick()

Invoke this method to explicitly process change detection and its side-effects.
tick(): void
      
      tick(): void

Parameters

There are no parameters.

Returns

void

In development mode, tick() also performs a second change detection cycle to ensure that no further changes are detected. If additional changes are picked up during this second cycle, bindings in the app have side-effects that cannot be resolved in a single change detection pass. In this case, Angular throws an error, since an Angular application can only have one change detection pass during which all change detection must complete.

attachView()

Attaches a view so that it will be dirty checked. The view will be automatically detached when it is destroyed. This will throw if the view is already attached to a ViewContainer.
attachView(viewRef: ViewRef): void
      
      attachView(viewRef: ViewRef): void

Parameters

viewRef

Type: ViewRef.

Returns

void

detachView()

Detaches a view from dirty checking again.
detachView(viewRef: ViewRef): void
      
      detachView(viewRef: ViewRef): void

Parameters

viewRef

Type: ViewRef.

Returns

void