What is that metadata object which @NgModule decorator takes in Angular?

Question

I was studying about Ngmodule from the official website of the Angular. There, it is written the following statement:

@NgModule takes a metadata object that tells Angular how to compile and launch the application.

I searched on many pages but I am confused about that object. So, can anyone please tell me what is that metadata object which the NgModule takes?

https://github.com/angular/angular/blob/master/packages/core/src/metadata/ng_module.ts#L70-L185 — yurzui, Jan 03 '18 at 06:24

score 1 · Accepted Answer · answered Jan 03 '18 at 06:50

Components, Services, Directives all are classes in angular 2+. But their expected behavior differs with the decorator (like @NgModule, @Component) declared in their class.

NgModule decorator used to set up angular module. Its a notation that says the class is not an ordinary class. Its a module.

NgModule takes metadata object like imports , declarations , bootstrap , providers

imports used to import the dependent module like BrowserModule, FormsModule, HttpModule
declaration used to import components
bootstrap defines the root application component
providers defines the services



     @NgModule({
              bootstrap: [AppComponent],
              declarations: [
                AppComponent,
                CustomerSelectionComponent,
                ResetPasswordComponent,
                DashboardComponent,
            ],
            imports: [ // import Angular's modules
                BrowserModule,
                FormsModule,
                ReactiveFormsModule,
                HttpModule,
                LoginModule,
            ],
            providers: [ // expose our Services and Providers into Angular's dependency injection
                ENV_PROVIDERS,
                APP_PROVIDERS,
                DatePipe
            ]
       })

What is that metadata object which @NgModule decorator takes in Angular?

1 Answers1