How to throw an observable error manually?

Question

I am working on an Angular app in which I am making a rest call through HTTP as below:

login(email, password) {     let headers = new Headers();     headers.append('Content-Type', 'application/x-www-form-urlencoded');     let options = new RequestOptions({ headers: headers });     let body = `identity=${email}&password=${password}`;     return this.http.post(`${this._configService.getBaseUrl()}/login`, body, options)     .map((res: any) => {         let response: any = JSON.parse(res._body);         if (response.success == 0) {           Observable.throw(response);  // not working         } else if (response.success == 1) {           console.log('success');           localStorage.setItem('auth_token', 'authenticated');           this.loggedIn = true;           return response;         }     }); } 

Basically I want my component to get response & error in my subscribe call, i.e.

this._authenticateService.login(this.loginObj['identity'],this.loginObj['password']).subscribe(   (success)=>{           this.credentialsError=null;       this.loginObj={};       this._router.navigate(['dashboard']);       },   (error)=>{     console.log(error);             this.credentialsError=error;        } ); 

but my API always returns success as it is defined that way.

How can I throw an error message if response.success == 0, so that it will be accessed inside error argument of my subscribe callback?

Answer 1

if (response.success == 0) {    throw Observable.throw(response);    }  

Edit for rxjs 6:

if (response.success == 0) {    throw throwError(response);    }  

Answer 2

rxjs 6

import { throwError } from 'rxjs';  if (response.success == 0) {   return throwError(response);   } 

rxjs 5

import { ErrorObservable } from 'rxjs/observable/ErrorObservable';  if (response.success == 0) {   return new ErrorObservable(response);   } 

What you return with ErrorObservable is up to you