Angular2：无法返回从Http响应映射的json

Question

In my service I execute an http call and return the response as Observable

doQuery ( query: String ) : Observable<any> {
    return this.http.request(queryURL) ;   
}

And in a component I subscribe

this.service
    .doQuery(this.query)
    .subscribe((res: any) => {
        console.log ("Res");
        console.log(res);
    });

Doing this actually works; I can see in the console the dump of a Response object

My problem came when I want to return from the service the response alread mapped as json.

I trying to do tyhis

return this.http.request(queryURL).map((res: any) => res.json());

But at runtime I got an obscure javascript error (this is coming from Zone.js to be precise)

Error: Permission denied to access property "rejection"

I've already tried to change the return type from Observable<any> to Observable<any[]> , as seen on a book, but without success.

UPDATE : Actually I resolved adding into the service file this import 'rxjs/Rx';

What am I doing wrong? Why is this import needed ? Isn't a way to import Rxjs' map operator?

Answer 1

In this specific situation, i resolved adding the import

import `rxjs/Rx`;

But in the 99% of other times this happened again to me, this error was due to a missing declaration of one service in the providers array in the @NgModule