Http

Class Description

Performs http requests using XMLHttpRequest as the default backend.

Http is available as an injectable class, with methods to perform http requests. Calling request returns an Observable which will emit a single Response when a response is received.

Example

import {Http, HTTP_PROVIDERS} from '@angular/http';
import 'rxjs/add/operator/map'
@Component({
  selector: 'http-app',
  viewProviders: [HTTP_PROVIDERS],
  templateUrl: 'people.html'
})
class PeopleComponent {
  constructor(http: Http) {
    http.get('people.json')
      // Call map on the response observable to get the parsed people object
      .map(res => res.json())
      // Subscribe to the observable to get the parsed people object and attach it to the
      // component
      .subscribe(people => this.people = people);
  }
}

Example

http.get('people.json').subscribe((res:Response) => this.people = res.json());

The default construct used to perform requests, XMLHttpRequest, is abstracted as a "Backend" ( XHRBackend in this case), which could be mocked with dependency injection by replacing the XHRBackend provider, as in the following example:

Example

import {BaseRequestOptions, Http} from '@angular/http';
import {MockBackend} from '@angular/http/testing';
var injector = Injector.resolveAndCreate([
  BaseRequestOptions,
  MockBackend,
  {provide: Http, useFactory:
      function(backend, defaultOptions) {
        return new Http(backend, defaultOptions);
      },
      deps: [MockBackend, BaseRequestOptions]}
]);
var http = injector.get(Http);
http.get('request-from-mock-backend.json').subscribe((res:Response) => doSomething(res));

Annotations

@Injectable()

Constructor

constructor(_backend: ConnectionBackend, _defaultOptions: RequestOptions)