Angular2 global service provider

Question

/app
        - app.component.ts 
        - app.component.html (hide/show: menu bar)
        - app.global.service.ts (Public varible LoginSuccess:boolean)
        - m         


        

Answer 1

You should provide GlobalService at bootstrap, and not for each component:

bootstrap(AppComponent, [GlobalService])

@Component({
  providers: [], // yes
  // providers: [GlobalService], // NO.
})
class AppComponent {
  constructor(private gs: GlobalService) {
    // gs is instance of GlobalService created at bootstrap
  }
}

This way GlobalService will be a singleton.

For more advanced approach see this answer.