Interceptors in Angular2

Question

I am trying to build a demo app on Angular2.beta.0 which would have login mechanism and then all the other API calls would have the acquired session token s

Answer 1

first in app.module.ts add following line at providers array:

    {provide : Http, useFactory: (xhrBackend: XHRBackend, requestOptions:  RequestOptions) => new HttpInterceptor(xhrBackend, requestOptions),deps:  [XHRBackend, RequestOptions]}

Create HttpIntreceptor file with

    import {Http, RequestOptionsArgs, RequestOptions, Response, Request, ConnectionBackend} from "@angular/http";
    import {Observable} from "rxjs/Observable";
    import "rxjs/add/operator/catch"; 
    import "rxjs/add/observable/throw";
    import "rxjs/add/observable/empty";
    import {Router} from "@angular/router";

    export class HttpInterceptor extends Http {
        constructor(backend: ConnectionBackend, defaultOptions: RequestOptions,    private _router: Router) {
            super(backend, defaultOptions);
        }

        request(url: string | Request, options?: RequestOptionsArgs):      Observable {
            return this.intercept(super.request(url, options));
        }

        get(url: string, options?: RequestOptionsArgs): Observable {
            return this.intercept(super.get(url,options));
        }

        post(url: string, body: string, options?: RequestOptionsArgs): Observable {
            return this.intercept(super.post(url, body, options));
        }

        put(url: string, body: string, options?: RequestOptionsArgs): Observable {
            return this.intercept(super.put(url, body, options));
        }

        delete(url: string, options?: RequestOptionsArgs): Observable {
            return this.intercept(super.delete(url, options));
        }

        intercept(observable: Observable): Observable {
            return observable.catch((err, source) => {
            });
        }
    }