keycloak.http.ts

import {Injectable} from "@angular/core";
import {Http, Request, ConnectionBackend, RequestOptions, RequestOptionsArgs, Response, Headers} from "@angular/http";

import {KeycloakService} from "./keycloak.service";
import {Observable} from 'rxjs/Rx';

/**
 * This provides a wrapper over the ng2 Http class that insures tokens are refreshed on each request.
 */
@Injectable()
export class KeycloakHttp extends Http {
    constructor(_backend: ConnectionBackend, _defaultOptions: RequestOptions, private _keycloakService: KeycloakService) {
        super(_backend, _defaultOptions);
    }

    /**
     * Performs any type of http request. First argument is required, and can either be a url or
     * a {@link Request} instance. If the first argument is a url, an optional {@link RequestOptions}
     * object can be provided as the 2nd argument. The options object will be merged with the values
     * of {@link BaseRequestOptions} before performing the request.
     */
    request(url: string | Request, options?: RequestOptionsArgs): Observable<Response> {
        const tokenPromise: Promise<string> = this._keycloakService.getToken();
        const tokenObservable: Observable<string> = Observable.fromPromise(tokenPromise);

        if (typeof url === 'string') {
            return tokenObservable.map(token => {
                const authOptions = new RequestOptions({headers: new Headers({'Authorization': 'Bearer ' + token})});
                return new RequestOptions().merge(options).merge(authOptions);
            }).concatMap(opts => super.request(url, opts));
        } else if (url instanceof Request) {
            return tokenObservable.map(token => {
                url.headers.set('Authorization', 'Bearer ' + token);
                return url;
            }).concatMap(request => super.request(request));
        }
    }

}