OnPush constant

int const OnPush

An optimized form of change detection, skipping some checks for changes.

Unlike Default, OnPush waits for the following signals to check a component:

• An @Input() on the component being changed.
• An @Output() or event listener (i.e. (click)="...") being executed in the template of the component or a descendant.
• A call to <ChangeDetectorRef>.markForCheck() in the component or a descendant.

Otherwise, change detection is skipped for this component and its descendants. An OnPush configured component as a result can afford to be a bit less defensive about caching the result of bindings, for example.

WARNING: It is currently undefined behavior to have a Default configured component as a child (or directive) of a component that is using OnPush. We hope to introduce more guidance here in the future.

Implementation

static const OnPush = 5;