Angular Di

A focused reference for Angular's dependency injection system that covers both modern patterns like the inject() function and traditional constructor injection. You get practical examples for common scenarios like hierarchical injectors, InjectionTokens, and factory providers, plus the decorators you need to know like @Optional and @SkipSelf. The guidance is clearly oriented toward Angular 21's functional approach while still covering the older patterns you'll encounter in existing codebases. If you're constantly looking up the syntax for multi providers or can't remember how forwardRef works, this consolidates the essentials. The examples are concise and ready to adapt, which beats scanning through official docs when you just need to wire up a service correctly.

skills.sh installs: 175
GitHub stars: 7
last updated: Aug 21, 2026

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Install

$ npx -y skills add oguzhan18/angular-ecosystem-skills --skill angular-di --agent claude-code

Installs into .claude/skills of the current project.

Files

Angular Dependency Injection

Version: Angular 21 (2025) Tags: DI, Services, Providers, Tokens, inject()

References: DI Guide • API • inject()

API Changes

This section documents recent version-specific API changes.

NEW: Functional injection with inject() — Preferred over constructor injection in modern Angular source
NEW: inject() with Optional decorator — inject(Service, { optional: true })
NEW: inject() with SkipSelf — inject(Service, { skipSelf: true })
NEW: Tree-shakable InjectionToken — new InjectionToken<T>(desc, { providedIn: 'root' })

Best Practices

Use providedIn: 'root' for singleton services

@Injectable({ providedIn: 'root' })
export class LoggerService {
  log(message: string) { console.log(message); }
}

Use inject() function for cleaner code

@Component({})
export class MyComponent {
  private service = inject(MyService);
  private router = inject(Router);
}

SKILL.md on GitHub

Details

Repository: github.com/oguzhan18/angular-ecosystem-skills
Category: Frontend Development
First seen: Jun 3, 2026