如何使用服务在角度6中消除错误？

Question

I make a service and used that service in component .mY code is working fine .But I am getting tslint error why ? function on which I am getting error

getUsers(): Observable<HttpResponse<UserModel>> {
    return this.http.get<UserModel>(this.configUrl).pipe(
      catchError(this.handleError)
    );
  }

code https://stackblitz.com/edit/angular-4pkct8?file=src%2Fapp%2Fuserdetail.service.ts

Answer 1

You need to typecast response like this -

getUsers(): Observable<HttpResponse<UserModel>> {
return this.http.get<HttpResponse<UserModel>>(this.configUrl).pipe(
  catchError(this.handleError)
 );
}

Answer 2

You are type casting your http.get to <UserModel> , but your method expects you to return Observable<HttpResponse<UserModel>> .

Change to method signatures return value to Observable<UserModel> so they match.

getUsers(): Observable<UserModel> {
  return this.http.get<UserModel>(this.configUrl).pipe(
    catchError(this.handleError)
  );
}

Answer 3

Your error is because "throwerror()" returns an Observable<never>

You are returning two different types one on success ( Observable<UserModel> ) and one on error ( Observable<never> ).

The below would stop your error showing albeit maybe not having the result you want

getUsers(): Observable<HttpResponse<UserModel>> | Observable<never> {
   return this.http.get<HttpResponse<UserModel>>(this.configUrl).pipe(
     catchError(this.handleError)
);

}