angular-standalone（Angular standalone 命令行）

Angular Standalone Components

Version: Angular 21 (2025) Tags: Standalone, Components, Imports, Bootstrap

References: Standalone Guide • Migration

API Changes

This section documents recent version-specific API changes.

• NEW: Standalone by default — New components are standalone by default since Angular 17
• NEW: provideRouter for standalone — Use functional providers instead of RouterModule
• NEW: ng generate @angular/core:standalone — Migration schematic
• DEPRECATED: NgModule — Migration to standalone components recommended

Best Practices

• Create standalone components

@Component({
  standalone: true,
  imports: [CommonModule, MatButtonModule],
  selector: 'app-my',
  template: `<button>Click</button>`
})
export class MyComponent {}

• Use imports array for dependencies

@Component({
  standalone: true,
  imports: [
    CommonModule,
    RouterModule,
    MatCardModule,
    MyChildComponent
  ],
  template: `
    <mat-card>
      <app-my-child></app-my-child>
    </mat-card>
  `
})
export class ParentComponent {}

• Bootstrap standalone component

// main.ts
import { bootstrapApplication } from '@angular/platform-browser';
import { AppComponent } from './app/app.component';
import { appConfig } from './app/app.config';

bootstrapApplication(AppComponent, appConfig)
  .catch(err => console.error(err));

• Use functional providers

export const appConfig: ApplicationConfig = {
  providers: [
    provideRouter(routes),
    provideHttpClient(),
    provideAnimations()
  ]
};

• Use provideZoneChangeDetection

export const appConfig: ApplicationConfig = {
  providers: [
    provideZoneChangeDetection({ eventCoalescing: true })
  ]
};

• Migrate from NgModule

# Full migration
ng generate @angular/core:standalone

# Specific component
ng generate @angular/core:standalone --path=path/to/component

• Use Router Outlet with standalone

@Component({
  standalone: true,
  imports: [RouterOutlet],
  template: `<router-outlet></router-outlet>`
})
export class AppComponent {}

• Lazy load standalone components

const routes: Routes = [
  {
    path: 'admin',
    loadComponent: () => import('./admin/admin.component').then(m => m.AdminComponent)
  }
];

• Use forwardRef for circular imports

@Component({
  standalone: true,
  imports: [forwardRef(() => OtherComponent)]
})
export class MyComponent {}

• Export standalone components

@Component({
  standalone: true,
  exports: [MyComponent],
  imports: [MyComponent]
})
export class FeatureComponent {}