Service instance is not available for child component in angular2

Question

I have created some services which should be shared within whole application but for some reason child components are throwing error Error: DI Exception at NoProviderE

Answer 1

I think you do something the right way to specify your providers when bootstrapping your application.

You probably don't import correctly your service in the boot module. You could check that categoryService isn't undefined here:

import { categoryService } from './something';

console.log(categoryService); // <-----

bootstrap(AppComponent, [
  JwtHelper,
  HTTP_PROVIDERS, authervice, ROUTER_PROVIDERS, 
  categoryService,
  Configuration
]);