when i subscribe my Observable, my next is not working

April 8, 2022

myObservable():Observable<boolean>{
  const result = new Subject<boolean>();
  result.next(true);
  result.complete();
  return result.asObservable();
}

this.myObservable().subscribe(x=> console.log(x));

when i subscribe my Observable which function name is myObservable
but the console never working

this.myObservable().subscribe({
next: _response => {console.log('next');}
        error: error => {
            console.log('had an error');
       },
       complete: () => {
           console.log('complete');
           this.accountDataLoaded = true;
       }})

try the life cycle console
the complete was print but next is not

>Solution :

The code does :

Create an Observable
Emit a value : true
Complete the Observable
return the Observable
Subscribe to the next values from the Observable

Of course, no new values are emitted. That is why the callback will never be executed.

As an example, you can use a timeout if you want to emit the values after the subscription :

function myObservable():Observable<boolean>{
  const result = new Subject<boolean>();
  setTimeout(() => {
    result.next(true);
    result.complete();
  }, 1000)
  return result.asObservable();
}
this.myObservable().subscribe(x=> console.log(x));

But, as you created a Subject, you could also use a ReplaySubject which emits old values to new subscribers

function myObservable():Observable<boolean>{
  const result = new ReplaySubject<boolean>();
  result.next(true);
  result.complete();
  return result.asObservable();
}

this.myObservable().subscribe(x=> console.log(x));