Science Knowings: JavaScript Course For Social Media

Angular Services

Angular Services

Welcome back! In this session, we'll dive into Angular services, a powerful feature that enables modularity, reusability, and state management in your Angular applications.

What are Angular Services?

Services are classes in Angular that provide specific functionality. They are responsible for performing tasks that are not directly related to views or components, such as data access, logging, or business logic.

Why Use Angular Services?

Services offer several benefits:

  • Modularity: Split complex functionality into reusable modules.
  • Reusability: Share services across multiple components and applications.
  • State Management: Centralize and manage application state.

Creating an Angular Service

To create a service, use the @Injectable() decorator:

@Injectable({ providedIn: 'root' })
export class MyService { ... }

Service Providers

Providers specify how to create and inject services:

{ provide: MyService, useClass: MyService }

Dependency Injection

Angular uses dependency injection to automatically provide services to components:

constructor(private myService: MyService) { ... }

Using Services in Components

Import and inject the service into the component class, then use its methods and properties:

import { MyService } from './my.service';

@Component({ ... })
export class MyComponent {
  constructor(private myService: MyService) { ... }
}

Service Singleton vs. Factory

Singleton: A single instance shared across the entire application.
Factory: Creates a new instance each time it is injected.

Service Lifecycle

Services follow the Angular lifecycle:
- ngOnInit: Called after the service is initialized.
- ngOnDestroy: Called when the service is destroyed.

Benefits of Using Angular Services

  • Code Reusability: Share common functionality across components.
  • Organized Code: Keep business logic and data management separate from views.
  • Testability: Services are easy to test in isolation.

Best Practices for Angular Services

  • Keep Services Focused: Each service should have a specific purpose.
  • Use Dependency Injection: Inject dependencies instead of creating new instances.
  • Test Services Thoroughly: Ensure your services work as intended.

Common Pitfalls in Angular Services

  • Overuse of Singleton: Avoid singletons for stateful services.
  • Circular Dependencies: Avoid creating dependencies between services.
  • Not Using Providers: Always provide services properly to avoid errors.

Next Up: Angular Dependency Injection

In the next session, we'll dive into dependency injection in Angular, a powerful technique for managing dependencies in your applications. Follow us to learn more!