Error encountered: "Injection error: Angular2 + typescript + jspm : No provider found for Http ( App -> Provider -> Http )"

I am in the process of transitioning from Webpack to JSPM with system.js. Our application has a simple App component. I have been following the steps outlined in this article Angular 2 Starter Setup with JSPM, SystemJS and Typescript in atom (Part 1)

import {Component} from 'angular2/core';
import {Bus} from './business.service';

@Component({
  selector: 'app',
  template: `
  <p>Hello World</p>
  `,
  providers:[Bus]
})
export class App {
  constructor(private bus : Bus) { }
}

We also have a simple business service using Http

import {Injectable} from 'angular2/core';
import {Http, Response, Headers, RequestOptions} from 'angular2/http';
import {Observable}     from 'rxjs/Observable';

@Injectable()
 export class Bus {

  constructor(private http: Http){

  }
}

Everything was working fine with Webpack, but after switching to systemjs, I started getting the following error:

EXCEPTION: No provider for Http! (App -> Bus -> Http)

I came across a similar issue on StackOverflow here, but it seemed to be related to Angular2 alpha versions whereas we are using beta@7

I also experimented with the code snippet below:

import {Component} from 'angular2/core';
//import {Bus} from './business.service';
import {Http, Response, Headers, RequestOptions} from 'angular2/http';
@Component({
  selector: 'app',
  template: `
  <p>Hello World</p>
  `,
  providers:[Http]
})
export class App {
  constructor(private bus : Http) { }
}

However, the error message became even more confusing:

EXCEPTION: No provider for ConnectionBackend! (App -> Http -> ConnectionBackend)

I even attempted downgrading to angular2-beta@6 and angular2-beta@1. Can you help me identify what I might be doing wrong? Thank you.

Using loader versions:

<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="6b1812181f0e0601182b5b455a52455958">[email protected]</a>

Answer №1

-- RC.5

Include the HttpModule in the imports section of your AppModule:

@NgModule({
  imports: [HttpModule],
  ...
})
export class AppModule {}

<-- RC.5

Don't forget to add HTTP_PROVIDERS to the providers list when bootstrapping:

import {HTTP_PROVIDERS} from 'angular2/http';
<!-- -->
bootstrap(AppComponent, [HTTP_PROVIDERS]);

For more information, visit https://angular.io/docs/ts/latest/api/http/HTTP_PROVIDERS-let.html

Answer №2

When setting up your application, ensure you include the HTTP_PROVIDERS providers:

import {HTTP_PROVIDERS} from 'angular2/http';

bootstrap(AppComponent, [ HTTP_PROVIDERS ]);

If you prefer to define it at the component level, you can do so like this:

import {Component} from 'angular2/core';
//import {Bus} from './business.service';
import {Http, Response, Headers, RequestOptions, HTTP_PROVIDERS} from 'angular2/http';
@Component({
  selector: 'app',
  template: `
    <p>Hello World</p>
  `,
  providers:[HTTP_PROVIDERS] // <-----------
})
export class App {
  constructor(private bus : Http) { }
}

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