Angular 9 无法发帖请求

Question

I'm currentry just a begginner in Angular,

I'm trying make a post request using this function:

 signIn(user: User) {
    console.log("1");
    return this.http
      .post<any>(`${this.endpoint}/login`, user)
      .subscribe((res: any) => {
        console.log("2");
        localStorage.setItem("access_token", res.token);
        this.getUserProfile(res._id).subscribe(res => {
          this.currentUser = res;
          this.router.navigate(["user-profile/" + res.msg._id]);
        });
      });
  }

I tried to monitor the network (using the network tab in firefox), and I've found out that no data is sent.

When opening the console it displays "1" but not "2".

Thank you

Answer 1

You need to return the observable and subscribe to it there. Now you are returning a subscription so you might not know when actually the call is triggered. Also try to avoid nested subscriptions. You could use RxJS higher order operators (like switchMap ) to pipe multiple observables. Try the following

some service

signIn(user: User) : Observable<any> {
  return this.http.post<any>(`${this.endpoint}/login`, user).pipe(
    switchMap((user) => {
      localStorage.setItem("access_token", user.token);
      return this.getUserProfile(user._id);
    }
  );
}

component

ngOnInit() {
  this.someService.signIn(user).subscribe(
    res => {
      this.currentUser = res;
      this.router.navigate(["user-profile/" + res.msg._id]);
    },
    (error) => {
      // always good practice to handle HTTP observable errors
    }
  );
}