angular-app

name	angular-app
description	Angular playbook for internal enterprise and forms-heavy admin apps — standalone components, typed reactive forms, signals, DI services, routing, and testing. Use when the app class is internal enterprise/admin.
origin	Centra AI

Angular App Playbook

Doctrine pick for internal enterprise / forms-heavy admin UIs (see rules/stack-selection/frontend.md). Angular's opinionatedness is the point: one router, one forms system, DI, HttpClient, and i18n in a single frame that survives team turnover.

Use when: building a dense CRUD/admin surface, a forms-heavy internal tool, or any app where long-term maintainability across a rotating team beats bespoke flexibility.

Init

# Angular CLI is not on a fresh box; install on demand (see toolchain-bootstrap)
npm i -g @angular/cli
ng new admin-console --style=scss --ssr=false --routing
cd admin-console
ng serve

Prefer standalone components (default in modern Angular). Do not scaffold NgModules unless integrating legacy code. Add --ssr only if you actually need server rendering — an internal admin app rarely does.

Idiomatic structure

src/app/
  core/            # singletons: auth, http interceptors, guards, app-wide services
  shared/          # dumb reusable components, pipes, directives
  features/
    users/
      users.routes.ts
      user-list.component.ts
      user-detail.component.ts
      users.service.ts
  app.config.ts    # providers: router, http, interceptors
  app.routes.ts    # top-level routes, lazy-load feature routes

• One feature = one folder with its own *.routes.ts, lazy-loaded from the top level.
• core/ holds providedIn: 'root' services and interceptors. shared/ holds presentational pieces with no business logic.

Routing and lazy loading

// app.routes.ts
export const routes: Routes = [
  { path: '', pathMatch: 'full', redirectTo: 'users' },
  {
    path: 'users',
    canActivate: [authGuard],
    loadChildren: () => import('./features/users/users.routes').then(m => m.USERS_ROUTES),
  },
];

Lazy-load every feature with loadChildren/loadComponent. Use functional guards (CanActivateFn) and functional interceptors (HttpInterceptorFn) — the class-based forms are legacy.

Data: signals + HttpClient

@Injectable({ providedIn: 'root' })
export class UsersService {
  private http = inject(HttpClient);
  list() { return this.http.get<User[]>('/api/users'); }
  create(u: NewUser) { return this.http.post<User>('/api/users', u); }
}

Use inject() over constructor injection in new code. Prefer signals for component state and toSignal() to bridge Observables; keep RxJS for streams and HTTP. Turn on provideHttpClient(withInterceptors([authInterceptor])) in app.config.ts.

Typed reactive forms — the reason to be here

form = new FormGroup({
  email: new FormControl('', { nonNullable: true, validators: [Validators.required, Validators.email] }),
  role: new FormControl<Role>('viewer', { nonNullable: true }),
});
// form.value is fully typed; form.controls.email.errors is typed

Reactive forms, not template-driven, for anything non-trivial. nonNullable: true to avoid null in the model. Build cross-field and async validators as functions. This typed-forms ergonomics is why enterprise admin picks Angular — lean into it.

Testing

• Unit: Jasmine + Karma ships with the CLI (ng test). Many teams swap to Jest or Vitest for speed — acceptable, state it.
• Component: TestBed with HttpClientTestingModule (or provideHttpClientTesting()) to assert requests without a network.
• E2E: Playwright (ng e2e scaffolds it). Protractor is dead — never use it.

Build and deploy

ng build            # outputs to dist/<app>/browser, hashed and minified

Serve the static browser/ output from any CDN/host; wire SPA fallback to index.html. For Railway, the detected start is a static serve of dist/ — see the railway-deploy skill. Set NG_APP_*/environment.ts values at build time; do not ship secrets to the client.

Common pitfalls

• Scaffolding NgModules in a new app — use standalone components.
• Template-driven forms for complex validation — use typed reactive forms.
• Constructor injection everywhere — prefer inject().
• Forgetting to lazy-load features — the initial bundle balloons.
• Reaching for Angular for a marketing site or a realtime chat app — wrong class; see the doctrine table.
• Leaving zone.js assumptions in code you want to move to zoneless/signals later.