Why event triggers ChangeDetection even if OnPush strategy is ON?

Question

When we use Default Strategy this guys could trigger Change Detection(of course except input params):

• user events
• timers
• aja

Answer 1

OnPush is defined this way.

It triggers change detection

• when a DOM event the component listens to was received
• when the |async pipe receives a new event
• when an @Input() was updated by change detection.
• when explicitly registering the component to be checked the next change detection turn using ChangeDetectorRef::markForCheck

ChangeDetectionStrategy.Default triggers change detection for every async callback called within Angulars zone (every DOM even listened to within the Angular application, every Observable event or completed Promise, setTimeout, ...)