Use transclusion to increase reusability in Angular

In Angular 2+, transclusion is a technique that allows you to pass content into a component from outside of the component's template. Transclusion is implemented using the Angular concept of Content Projection. Content Projection is a way of including content in a component that is not part of the component's template, but rather is passed in as a parameter.

To use transclusion in Angular 2+, you can define a component with a `<ng-content></ng-content>` tag in its template. The `<ng-content></ng-content>` tag acts as a placeholder for content that will be passed into the component from outside.

Here's an example:

typescript
@Component({
  selector: 'my-component',
  template: `
    <div>
      <h2>{{title}}</h2>
      <ng-content></ng-content>
    </div>
  `
})
export class MyComponent {
  @Input() title: string;
}

In the example above, the `MyComponent` component has a template that includes a `<ng-content></ng-content>` tag. When `MyComponent` is used in another template, any content inside the `<my-component>` tag will be inserted into the `<ng-content></ng-content>` tag in the `MyComponent` template.

Here's an example of how to use `MyComponent`:

html
<my-component title="Hello">
  <p>This is some content that will be transcluded.</p>
</my-component>

In the example above, the `<p>` tag and its contents will be transcluded into the `<ng-content></ng-content>` tag in the `MyComponent` template.

Pros:

  • Transclusion allows you to create more reusable components by allowing content to be passed in from outside the component.
  • It provides a way to create more flexible components that can be used in different contexts.
  • Transclusion makes it easier to create components with complex templates.

Cons:

  • Transclusion can make the structure of a component's template more complex, which can make it harder to understand and debug.
  • If the content being transcluded contains a lot of logic, it can make the component more difficult to test.
  • Transclusion can make it harder to enforce a consistent look and feel across an application.