import { ModuleWithProviders, NgModule } from '@angular/core'; import { CommonModule } from '@angular/common'; import { NotifierService } from './notifier.service'; import { MatIconModule } from '@angular/material/icon'; import { NotifierComponent } from './notifier/notifier.component'; import { MatSnackBarModule } from '@angular/material/snack-bar'; @NgModule({ declarations: [NotifierComponent], imports: [ CommonModule, MatIconModule, MatSnackBarModule ] }) export class NotifierModule { static forRoot(): ModuleWithProviders { return { ngModule: NotifierModule, providers: [ {provide: NotifierService} ] }; } }