References
Oleksa Novyk | GitHub

NgZone

This is the documentation for Angular 6.
You can switch to the latest version Angular 9.

An injectable service for executing work inside or outside of the Angular zone.

The most common use of this service is to optimize performance when starting a work consisting of one or more asynchronous tasks that don't require UI updates or error handling to be handled by Angular. Such tasks can be kicked off via runOutsideAngular and if needed, these tasks can reenter the Angular zone via run.

Links & Tutorials

Interface

Methods

run()#

run<T>(fn: (...args: any[]) => T, applyThis?: any, applyArgs?: any[]): T

Executes the fn function synchronously within the Angular zone and returns value returned by the function.

Running functions via run allows you to reenter Angular zone from a task that was executed outside of the Angular zone (typically started via runOutsideAngular).

Any future tasks or microtasks scheduled from within this function will continue executing from within the Angular zone.

If a synchronous error happens it will be rethrown and not reported via onError.

runTask()#

runTask<T>(fn: (...args: any[]) => T, applyThis?: any, applyArgs?: any[], name?: string): T

Executes the fn function synchronously within the Angular zone as a task and returns value returned by the function.

Running functions via run allows you to reenter Angular zone from a task that was executed outside of the Angular zone (typically started via runOutsideAngular).

Any future tasks or microtasks scheduled from within this function will continue executing from within the Angular zone.

If a synchronous error happens it will be rethrown and not reported via onError.

runGuarded()#

runGuarded()

Same as run, except that synchronous errors are caught and forwarded via onError and not rethrown.

runOutsideAngular()#

runOutsideAngular<T>(fn: (...args: any[]) => T): T

Executes the fn function synchronously in Angular's parent zone and returns value returned by the function.

Running functions via runOutsideAngular allows you to escape Angular's zone and do work that doesn't trigger Angular change-detection or is subject to Angular's error handling.

Any future tasks or microtasks scheduled from within this function will continue executing from outside of the Angular zone.

Use run to reenter the Angular zone and do work that updates the application model.

Properties

hasPendingMicrotasks#

hasPendingMicrotasks: boolean

Has pending microtasks.

hasPendingMacrotasks#

hasPendingMacrotasks: boolean

Has pending macrotasks.

isStable#

isStable: boolean

Whether there are no outstanding microtasks or macrotasks.

onUnstable#

onUnstable: EventEmitter<any>

Notifies when code enters Angular Zone. This gets fired first on VM Turn.

onMicrotaskEmpty#

onMicrotaskEmpty: EventEmitter<any>

Notifies when there is no more microtasks enqueued in the current VM Turn. This is a hint for Angular to do change detection, which may enqueue more microtasks. For this reason this event can fire multiple times per VM Turn.

onStable#

onStable: EventEmitter<any>

Notifies when the last onMicrotaskEmpty has run and there are no more microtasks, which implies we are about to relinquish VM turn. This event gets called just once.

onError#

onError: EventEmitter<any>

Notifies that an error has been delivered.