Random Angular Tips

Table of Contents

How to chain observables #

If observable2 (getAuthorizedApplications) depends on a finished observable1 (getSubjectToken) you can utilize mergeMap from rxjs:

class SomeClass {
    ...
    onCredentials(credentials: Credentials) {
        this.auth
            .getSubjectToken(credentials)
            .pipe(
              map((res) => res.headers.get('X-Subject-Token') ?? ''),
              tap((subjectToken) => {
                localStorage.setItem('X-Subject-Token', subjectToken);
              }),
              mergeMap((subjectToken) => {
                return this.auth.getAuthorizedApplications(subjectToken);
              })
            )
            .subscribe((res) => console.log(res));
    }
    ...
}