Angular decorators are special functions in Angular that add metadata to classes, methods, properties, or parameters. This metadata allows Angular to understand and manage these elements during runtime and extend their functionalities.
Here are the primary types of Angular decorators and how they are used:
Class Decorators: Used to define Angular elements like components, directives, modules, pipes, and services.Example: @Component to define a component or @NgModule for a module.
typescript
@Component({
selector: 'app-example',
templateUrl: './example.component.html',
})
export class ExampleComponent {}
Property Decorators: Applied to class properties to configure their behavior.
Example: @Input to receive data from a parent component or @Output to emit events to a parent component.
typescript
@Input() myProperty: string;
@Output() myEvent = new EventEmitter();
Method Decorators: Used to define metadata for class methods.
Example: @HostListener to listen to DOM events on the host element.
typescript
@HostListener('click', ['$event'])
onHostClick(event: Event) {
console.log('Host element clicked!');
}
Parameter Decorators: Used to configure metadata for a class constructor parameter.
Example: @Inject to inject a specific dependency.
typescript
constructor(@Inject(SomeService) private service: SomeService) {}
These decorators play a critical role in Angular's dependency injection and component-based architecture, making your
application dynamic and modular. If you'd like, I can dive deeper into any specific type of decorator!