angular5: Type 'true' is not assignable to type 'Observable<boolean>

Question

I am trying to change the login status after the user login

component.ts

isLoggedIn$: Observable<boolean>; 

  constructor (private auth:Auth){}

  ngOnInit (){


     this.isLoggedIn$ = this.auth.getUser()

     console.log(this.isLoggedIn$);

  }

Auth.ts

@Injectable()
export class Auth {

    private user:boolean = false;

     setUser(){

        this.user= true;
     }

     getUser(){
        return this.user
     }

    removeUser(){
        this.user = false;
    }

}

But i got the following error

error TS2322: Type 'true' is not assignable to type 'Observable'

You are expecting an Observable of boolean value but returning just a boolean value. This code will make more sense if you are returning Observable from a http call which maps to a boolean value asynchronously. — sabithpocker
– sabithpocker, Commented Mar 1, 2018 at 5:10
Are you using isLoggedIn$ in your template? If so, you can use it like *ngIf="isLoggedIn$ | async" — AdityaParab
– AdityaParab, Commented Mar 1, 2018 at 8:02
yes i am using it do i need to add a subscriber to listen the change — shamon shamsudeen
– shamon shamsudeen, Commented Mar 1, 2018 at 8:46

sabithpocker · Accepted Answer · 2018-03-01 05:16:49Z

1

If you are mocking http without an actual service, you can wrap the loggedIn status in an Observable as shown below for a quick fix. Take a look at rxjs and understand Observables for a better understanding.

@Injectable()
export class Auth {

    private user:boolean = false;

     setUser(){

        this.user= true;
     }

     getUser(): Observable<boolean>{
        return Observable.of(this.user)
     }

    removeUser(){
        this.user = false;
    }

}

Also: console.log(this.isLoggedIn$) will not work like that.

answered Mar 1, 2018 at 5:16

sabithpocker

15.6k1 gold badge44 silver badges78 bronze badges

Sign up to request clarification or add additional context in comments.

8 Comments

shamon shamsudeen Over a year ago

i am getting this error ` Observable_1.Observable.of is not a function at Auth.getUser`

sabithpocker Over a year ago

You need to import those. import { Observable } from 'rxjs/Observable'; import 'rxjs/add/observable/of';

sabithpocker Over a year ago

You will be better off using Promise + async function in this case.

shamon shamsudeen Over a year ago

but why its not update the value?? this component is common to all

sabithpocker Over a year ago

How are you using the value? If its in template you can use isLoggedIn$ | async. Else you will have to subscribe

|

Collectives™ on Stack Overflow

angular5: Type 'true' is not assignable to type 'Observable<boolean>

1 Answer 1

8 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

8 Comments

Your Answer

Sign up or log in

Post as a guest

Related