react-query/examples/angular/basic-persister/src/app/app.component.html

<p>
  Try to mock offline behavior with the button in the devtools. You can navigate
  around as long as there is already data in the cache. You'll get a refetch as
  soon as you go "online" again.
</p>
@if (postId() > -1) {
  <post [postId]="postId()" (setPostId)="postId.set($event)"></post>
} @else {
  <posts (setPostId)="postId.set($event)" />
}