Exploring the wonders of using the Async Pipe with Reactive Extensions

I'm facing a little issue with the async pipe in Angular. Here's my scenario: I need to execute nested observables using the async pipe in HTML because I'm utilizing the on-push change detection strategy and would like to avoid workarounds or manually triggering change detection. The problem I'm encountering is that only the first observable seems to get called. Do I need to add return statements or what could be causing this issue?

Typescript code

this.http.getUsers(criteria)
.pipe(map(data => {
  data.users.map(user => {
    this.http.getUserData(user.id)
    .pipe(map(res => { user.data = res.data;}));
  });
}));

HTML code

<div *ngFor="let user of users$ | async"></div>

Answer №1

If you are planning to use switchMap, it is necessary to assign an observable to the users$ property.

users$ = this.http.fetchUsers(criteria).pipe(
  switchMap(user => this.http.getUserDetails(user.id)),
  map(response => response.data)
);

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