Trigger selectionchange event from formArray control typescript

Trigger selectionchange event from formArray control in TypeScript

If you’re working with Angular and TypeScript, you may have encountered a scenario where you need to trigger the selectionchange event from a formArray control. This event is commonly used for handling changes in select dropdowns, and being able to trigger it programmatically can be useful in certain situations.

In this blog post, we’ll explore two different solutions to trigger the selectionchange event from a formArray control in TypeScript.

Solution 1: Using the ElementRef

The first solution involves using the ElementRef class from Angular’s core library. This class provides access to the underlying DOM element, allowing us to trigger events directly.

Here’s an example code snippet that demonstrates how to trigger the selectionchange event using the ElementRef:

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

@Component({
  selector: 'app-example',
  template: `
    
      Option 1
      Option 2
      Option 3
    
  `
})
export class ExampleComponent {
  @ViewChild('mySelect') mySelect: ElementRef;

  triggerSelectionChange() {
    const event = new Event('selectionchange');
    this.mySelect.nativeElement.dispatchEvent(event);
  }

  onSelectionChange(event: Event) {
    // Handle the selection change event here
  }
}

In the above code, we define a select element with a reference variable #mySelect. We then use the @ViewChild decorator to access this element in our component class. Inside the triggerSelectionChange method, we create a new selectionchange event using the Event constructor and dispatch it on the nativeElement of the mySelect element.

Solution 2: Using Renderer2

The second solution involves using Angular’s Renderer2 class. This class provides a safe way to interact with the DOM, even in environments where direct access to the DOM is restricted.

Here’s an example code snippet that demonstrates how to trigger the selectionchange event using the Renderer2:

import { Component, Renderer2, ViewChild } from '@angular/core';

@Component({
  selector: 'app-example',
  template: `
    
      Option 1
      Option 2
      Option 3
    
  `
})
export class ExampleComponent {
  @ViewChild('mySelect') mySelect: ElementRef;

  constructor(private renderer: Renderer2) {}

  triggerSelectionChange() {
    const event = new Event('selectionchange');
    this.renderer.dispatchEvent(this.mySelect.nativeElement, event);
  }

  onSelectionChange(event: Event) {
    // Handle the selection change event here
  }
}

In the above code, we inject the Renderer2 class into our component’s constructor. Inside the triggerSelectionChange method, we create a new selectionchange event using the Event constructor and dispatch it using the dispatchEvent method of the Renderer2 class.

Both solutions allow you to trigger the selectionchange event from a formArray control in TypeScript. Choose the solution that best fits your project’s requirements and coding style.

That’s it! You now know how to trigger the selectionchange event from a formArray control in TypeScript. Happy coding!