What is ElementRef class in Angular?

The ElementRef class in Angular is a class that represents a reference to a specific element in the Angular application. It is commonly used to access and manipulate elements in the DOM (Document Object Model) within Angular components, directives, and services.

When working with Angular, there are often situations where you need to directly interact with elements in the DOM. This could be to read the properties of an element, modify its styles, or attach event listeners to it. The ElementRef class provides a way to do this in a safe and controlled manner within the Angular framework.

Here is a basic example of how the ElementRef class can be used in an Angular component:

    
import { Component, ElementRef, ViewChild } from '@angular/core';

@Component({
  selector: 'app-example',
  template: '
Hello, World!
'
})
export class ExampleComponent {
  @ViewChild('exampleDiv') exampleDiv: ElementRef;

  ngAfterViewInit() {
    // Accessing the native element and changing its background color
    this.exampleDiv.nativeElement.style.backgroundColor = 'lightblue';
  }
}
    
  

In the example above, the ElementRef class is used in conjunction with the @ViewChild decorator to get a reference to the div element with the template reference variable #exampleDiv. Once the component has been initialized, the ngAfterViewInit() lifecycle hook is used to access the native element of exampleDiv and change its background color to ‘lightblue’.

It is important to note that while the ElementRef class provides direct access to elements in the DOM, it is typically recommended to use Angular’s data binding and property binding features whenever possible to manipulate the DOM in a more declarative and Angular-specific way.

Overall, the ElementRef class in Angular is a powerful tool for working with the DOM when needed, but it should be used judiciously and with caution to maintain the encapsulation and reusability of Angular components.