Angular getting response body

Question

I'm having trouble understanding how one is supposed to get the response body from an Angular Response object. In their docs they have an example that states

http.request('my-friends.txt').subscribe(response => this.friends = response.text());

yet when I attempt to do let body: string = response.text(); I get an error saying "Argument of type 'Promise' is not assignable to parameter of type 'string'".

I tried treating it as a promise and doing

let body: string; response.text().then(text => body = text);

which removes the compilation error, but when this code gets invoked it throws and error saying "TypeError: response.text(...).then is not a function".

I would like to understand what exactly a Promise is and how I need to retrieve it's properties.

Answer 1

I believe you've referenced the wrong Response object in your imports. If you're specifying the type need to import Response object from Angular package:

import { Response } from '@angular/http`;

There is also Response object from fetch API supported natively by browsers. They differ in that Angular Response object returns string for Response.text() method, while fetch API Response returns a promise. The http service uses Angular's Response object and it returns a string so you don't need a promise here.

If you want to save the body text to the body variable, you have to do it when you get the value from an observable:

http.request('my-friends.txt').subscribe((response: Response) => this.body = response.text());