observable wrapper for angular2 Http, using jQuery as a temporary solution to allow withCredentials property on xhr object

observable-request-service.ts

/// <reference path='../../typings/angularjs/angular.d.ts' />
//TODO - a temp fix is using jquery ajax until angular2/http adds support for withCredentials on their xhr objects
import {Http, Headers} from 'angular2/http';
import {Injectable, Observable} from 'angular2/core';

@Injectable()
export class ObservableRequestService {
    constructor(private http:Http) {
    }

    get(relativePath:string, formatter:Function = null):Observable<any> {
        return this.http.get(relativePath).map(this.mapper);
    }

    delete(relativePath:string, details) {
        return this.doRequest('DELETE', relativePath, details);
    }

    post(relativePath:string, details) {
        return this.doRequest('POST', relativePath, details);
    }

    private doRequest(method, relativePath, data):Observable<any> {
        return Observable.fromPromise($.ajax({
            url: relativePath,
            method: method,
            contentType: 'application/json',
            data: JSON.stringify(data),
            xhrFields: {
                withCredentials: true
            }
        })).map(this.mapper);
    }

    private mapper(response:{json: Function}) {
        return response.json();
    }
}

https://github.com/angular/http/issues/65
The above is more of an experiment with Observables (which can also be done with window.fetch and polyfills etc).
Best approach considering we are in angular2 world is to use the workaround:
https://github.com/angular/http/issues/65#issuecomment-181560171