import {APP_INITIALIZER, ModuleWithProviders, NgModule} from '@angular/core';
import {CommonModule} from '@angular/common';
import {MetaService} from './meta.service';

@NgModule({
  imports: [
    CommonModule,
  ]
})
export class MetaModule {

  static forRoot(): ModuleWithProviders {
    return {
      ngModule: MetaModule,
      providers: [
        MetaService,
        {
          provide: APP_INITIALIZER,
          useFactory: init,
          multi: true,
          deps: [MetaService]
        }
      ]
    };
  }

}

export function init(service: MetaService) {
  const f = () => service.init();
  return f;
}