未在Observable.create对象上触发订阅

Question

So I have the following:

const getAllData = Observable.create( () => {
    console.log(Date.now() + ' - Calling getallcontenttypes');
    this.getAllContentTypes();
    console.log(Date.now() + ' - Calling getalltaxonomysitecolumns');
    this.getAllTaxonomySiteColumns();
  });
  getAllData.subscribe( () => {
    console.log(Date.now() + ' - Subscribed, data loaded, calling router...');
    this.router.navigateByUrl('/contenttype');
  });  

The functions inside my const getAllData work, get the data and handle it (with additional console logs so I know there's values and they run through those functions).

What I want to do now is, once all my functions (for now 2) inside my getAllData are finished getting & handling all the data, I want to reroute to another view. Those 2 functions (getall...) return void now. This is all inside my ngOnInit().

But so far it seems like the .subscribe() doesn't trigger or maybe I'm doing it wrong. Can anyone see what's the issue?

For example, here's the getAllContentTypes function:

public getAllContentTypes() {

const jsonStringified = JSON.stringify(json);

this.contentTypeService.getAllContentTypes(jsonStringified).pipe(
  operators.tap(res => this.convertJsonResultToArrayCT(res)))
  .subscribe(res2 => this.storeInSessionStorage(res2, 'ContentTypes'));
}  

public storeInSessionStorage(res: any, key: string) {
    sessionStorage.setItem(key, JSON.stringify(this.contentTypeArray));
    console.log(Date.now() + ' - Stored in sessionstorage: ' + key);
}  

And here's an image of what I get in my console: https://imgur.com/a/xQhaqjv .

EDIT:

OK So I've modified my functions to return Observables:

public getAllContentTypes(): Observable<ContentType> {

const jsonStringified = JSON.stringify(json);

this.contentTypeService.getAllContentTypes(jsonStringified).pipe(
  operators.tap(res => this.convertJsonResultToArrayCT(res)))
  .subscribe(res2 => this.storeInSessionStorage(res2, 'ContentTypes'));

return from(this.contentTypeArray);

}

I've also edited my code as such:

const test = forkJoin(
    this.getAllContentTypes(),
    this.getAllTaxonomySiteColumns()
  ).subscribe( () => {
    console.log(Date.now() + ' - Subscribed, data loaded, calling router...');
    this.router.navigateByUrl('/contenttype');
  });  

But subscribe isn't triggered.

Answer 1

When you create an observable with the method create(), you have to pass an observer as an argument so you can call next(), error() or complete() on it later, eg

const getAllData = Observable.create( observer => { 
                                     observer.next('123');
                                    });

When the code subscribes to this observable, it has to pass a function to handle the emitted value, and optionally error and completion, ie the observer eg

getAllData.subscribe(value => console.log(value));  // prints 123

I have a working code sample here: https://codepen.io/yfain/pen/xLaMdN?editors=1012