Addressing command problems in Angular

Question

Addressing command problems in Angular

I am experiencing an issue with a dropdown functionality. When a user selects an option and then presses either the "Delete" or "Backspace" button on the keyboard, the value from the dropdown clears which is working correctly. However, I am attempting to implement a Directive that achieves the same effect but I am facing challenges in making it work. Can anyone provide guidance on how to properly create this directive?

Thank you in advance for your help!

Below is the code snippet:

VIEW LIVE DEMO

onKeyUp(evt){
   if(evt.keyCode === 8){
     this.isShowClear = false;
     let currentElementName = evt.currentTarget.getAttribute('name');
     this.myForm.controls[currentElementName].patchValue('');
 }
}

onChange(){
this.isShowClear = true;
}

angular typescript primeng

Answer 1

Answer №1

Check out this directive code snippet:

@Directive({
  selector: '[customDropDown]'
})
export class CustomDropDownDirective {

  @Output() updateProperty: EventEmitter<any> = new EventEmitter();

  constructor(private el: ElementRef, private control : NgControl) { }

    @HostListener('keyup',['$event'])onkeyup(event:any){
    if(event.keyCode === 8){
       let currentElementName = this.el.nativeElement.value;
      this.control.control.setValue('');
      this.updateProperty.emit(false);
    }
  }
}

Experience the LIVE DEMO where I enhanced your example. Don't forget to add your directive in app.component.ts, as it was missing in the demo causing it not to work.

Answer 2

Check out this directive code snippet:

@Directive({
  selector: '[customDropDown]'
})
export class CustomDropDownDirective {

  @Output() updateProperty: EventEmitter<any> = new EventEmitter();

  constructor(private el: ElementRef, private control : NgControl) { }

    @HostListener('keyup',['$event'])onkeyup(event:any){
    if(event.keyCode === 8){
       let currentElementName = this.el.nativeElement.value;
      this.control.control.setValue('');
      this.updateProperty.emit(false);
    }
  }
}

Experience the LIVE DEMO where I enhanced your example. Don't forget to add your directive in app.component.ts, as it was missing in the demo causing it not to work.

Answer 3

Answer №2

If you want to capture key events, using the keypress attribute is a great option. Here's an example of how you can do it:

@HostListener('document:keypress', ['$event'])
  handleKeyboardEvent(event: KeyboardEvent) { 
    this.key = event.key;

    // You can then check the keycode to see if it is for backspace or delete,
    // and remove data from a selector with the help of NgControl.
  }

Make sure to import NgControl from @angular/core before using it.

Answer 4

If you want to capture key events, using the keypress attribute is a great option. Here's an example of how you can do it:

@HostListener('document:keypress', ['$event'])
  handleKeyboardEvent(event: KeyboardEvent) { 
    this.key = event.key;

    // You can then check the keycode to see if it is for backspace or delete,
    // and remove data from a selector with the help of NgControl.
  }

Make sure to import NgControl from @angular/core before using it.

Addressing command problems in Angular

Answer №1

Answer №2

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