How does HTTP error-handling work with observables?

I think the issue is that you are not throwing the error with an Observable.throw(errMsg).

So, you may just use it like this:

.catch((error:any) => Observable.throw(error.json().error || 'Server error'));

In your example:

create(member: Member): Observable<any> {    return this.http      .post(this.RESOURCE_BASE_URL, member)      .map(response => {        if (response.status === 200) this.toastsSerivce.success(this.translateService.instant('lbl_users_member_created'));        return response;      })      .catch((error:any) => Observable.throw(this.toastsSerivce.error(this.translateService.instant('lbl_users_member_create_failed'))));  }

But, you could use an error handler, like the one Angular proposes here:

private handleError (error: Response | any) {    // In a real world app, you might use a remote logging infrastructure    let errMsg: string;    if (error instanceof Response) {      const body = error.json() || '';      const err = body.error || JSON.stringify(body);      errMsg = `${error.status} - ${error.statusText || ''} ${err}`;    } else {      errMsg = error.message ? error.message : error.toString();    }    console.error(errMsg);    return Observable.throw(errMsg);  }

And so, your method would look more like this:

create(member: Member): Observable<any> {    return this.http      .post(this.RESOURCE_BASE_URL, member)      .map(response => {        if (response.status === 200) this.toastsSerivce.success(this.translateService.instant('lbl_users_member_created'));        return response;      })      .catch(this.handleError);  }

It's actually cleaner and more reusable for other methods that you may create within your service.

I would suggest to use also a response handler, like the one used by Angular's devs: this.extractData.

Obviusly, inside the error handle method you can put your own custom logic, depends on how you want to show or handle the error.

NOTE: I did not test your code nor the code I posted here. But I wanted to show/express the concept. You should throw the error in order to not going into success everytime. How you handle it depends on you and your App.

It works for me:

this.http.post('http://example.com/path/', {sampleData: 'd'}).subscribe(  res => {alert('ok!');},  err => {alert(err.error)})