Optimizing Change Detection
Let's see how we can resolve the performance issues in an Angular application with the 'onPush' strategy.
We'll cover the following...
Change detection and performance
Every change triggers a noticeable pause in our hospital patient app. Angular is fast, but the app is currently forcing it to do thousands of checks anytime a change is made.
Like with any performance issue, there are multiple solutions, but in this case, we’ll focus on taking command of the change detection ourselves with the onPush
strategy.
Each component comes with its own change detector, allowing us to selectively override how a component handles change detection. The onPush
strategy relies on one or more observables annotated with @Input
to do change detection.
Instead of checking every round, components using onPush
only run change detection when any of the annotated observables emit an event.