Can lazy-loaded modules share the same instance of a service provided by their parent?

Question

I\'ve just run into a problem with a lazy-loaded module where parent and child module both require the same service but create an instance each. The declaration is identical

Answer 1

This should work but still I would suggest you to go with SharedModule concept which contains common services,pipes,directives and components.

Shared/SharedModule

import { NgModule,ModuleWithProviders } from '@angular/core';
import { CommonModule }        from '@angular/common';

import { MyService } from './my.service';

@NgModule({
  imports:      [ CommonModule ],
  declarations: [],
  exports:      [ CommonModule ]
})
export class SharedModule {
  static forRoot(): ModuleWithProviders {
    return {
      ngModule: SharedModule,
      providers: [ MyService ]                       //<<<====here
    };
  }
}

AppModule

import {SharedModule} from './shared/shared.module';
...
@NgModule({
   imports:[ BrowserModule,SharedModule.forRoot()],  //<<<====here
   providers: []
});