@angular/core

EmbeddedViewRef

Class

stable

Represents an Angular view in a view container. An embedded view can be referenced from a component other than the hosting component whose template defines it, or it can be defined independently by a TemplateRef.

API

    
      abstract class EmbeddedViewRef<C> extends ViewRef {}

context

C

The context for this view, inherited from the anchor element.

rootNodes

any[]

The root nodes for this embedded view.

destroy

void

Destroys this view and all of the data structures associated with it.

@returnsvoid

destroyed

boolean

Reports whether this view has been destroyed.

onDestroy

void

A lifecycle hook that provides additional developer-defined cleanup functionality for views.

@paramcallbackFunction

A handler function that cleans up developer-defined data associated with a view. Called when the destroy() method is invoked.

@returnsvoid

markForCheck

void

When a view uses the ChangeDetectionStrategy#OnPush (checkOnce) change detection strategy, explicitly marks the view as changed so that it can be checked again.

Components are normally marked as dirty (in need of rerendering) when inputs have changed or events have fired in the view. Call this method to ensure that a component is checked even if these triggers have not occurred.

@returnsvoid

detach

void

Detaches this view from the change-detection tree. A detached view is not checked until it is reattached. Use in combination with detectChanges() to implement local change detection checks.

Detached views are not checked during change detection runs until they are re-attached, even if they are marked as dirty.

@returnsvoid

detectChanges

void

Checks this view and its children. Use in combination with ChangeDetectorRef#detach to implement local change detection checks.

@returnsvoid

checkNoChanges

void

Checks the change detector and its children, and throws if any changes are detected.

Use in development mode to verify that running change detection doesn't introduce other changes. Calling it in production mode is a noop.

@deprecated

This is a test-only API that does not have a place in production interface. checkNoChanges is already part of an ApplicationRef tick when the app is running in dev mode. For more granular checkNoChanges validation, use ComponentFixture.

@returnsvoid

reattach

void

Re-attaches the previously detached view to the change detection tree. Views are attached to the tree by default.

@returnsvoid

Description

Properties of elements in a view can change, but the structure (number and order) of elements in a view cannot. Change the structure of elements by inserting, moving, or removing nested views in a view container.

Usage Notes

The following template breaks down into two separate TemplateRef instances, an outer one and an inner one.

Count: {{items.length}}<ul>  <li *ngFor="let  item of items">{{item}}</li></ul>

This is the outer TemplateRef:

Count: {{items.length}}<ul>  <ng-template ngFor let-item [ngForOf]="items"></ng-template></ul>

This is the inner TemplateRef:

  <li>{{item}}</li>

The outer and inner TemplateRef instances are assembled into views as follows:

<!-- ViewRef: outer-0 -->Count: 2<ul>  <ng-template view-container-ref></ng-template>  <!-- ViewRef: inner-1 --><li>first</li><!-- /ViewRef: inner-1 -->  <!-- ViewRef: inner-2 --><li>second</li><!-- /ViewRef: inner-2 --></ul><!-- /ViewRef: outer-0 -->