CODEWITHSUNDEEP
angular
Isuru
Isuru

Reputation: 970

Type 'Observable<{}>' is not assignable to type 'Observable<Token>'

Im completely new to Angular 2. Im getting this error Type 'Observable<{}>' is not assignable to type 'Observable<Token>'. Type {} is not assignable to type 'Token'. Property 'access_token' is missing in type {}.

Service 

import { Injectable } from '@angular/core';
import { Http, Response, Headers, RequestOptions, URLSearchParams } from    '@angular/http';
import { Token }           from './token';
import {Observable} from 'rxjs/Rx';

// Import RxJs required methods
import 'rxjs/add/operator/map';
import 'rxjs/add/operator/catch';

@Injectable()
export class TokenService {

  constructor(private http: Http) { }

  getToken(): Observable<Token> {

    var headers = new Headers();
    headers.append('Content-Type', 'application/x-www-form-urlencoded');

    var params = new URLSearchParams();
    params.append('UserName', '[email protected]');
    params.append('Password', 'Lasal@123');
    params.append('grant_type', 'password');


    return this.http.post('https://payd.azurewebsites.net//token', params.toString(), { headers })
      .map((res: Response) => res.json())
      .catch((error: any) => Observable.throw(error));

    }
  }
}

I would like to know the reason behind this error and the solution for this. Thanks in advance!

Upvotes: 0

Views: 1285

Answers (1)

Sasxa
Sasxa

Reputation: 41314

It's just Typescript letting you know you didn't assign types where you should.

getToken(): Observable<Token> {
  return this.http.post(...)
    .map((res: Response) => res.json())
}

This function expects to return an Observable, which it does since http.post() returns an observable. It also expects that this observable emits something of a type Token, but it is returning any:

         (res: Response): any => res.json()

Because http.post() doesn't actually know what you will get from server, it can't type that for you, you have to do it yourself:

         (res: Response): Token => res.json()

or create new instance of Token (if TS still complains):

         (res: Response): Token => new Token(res.json())

Upvotes: 2

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