useControlTouched

Returns whether an AbstractControl has been touched (interacted with) as a signal. The signal updates reactively whenever the control's touched state changes. Works with FormControl, FormGroup, and FormArray.

Usage

import { useControlTouched } from 'ng-reactive-utils';

@Component({
  template: `
    <input [formControl]="emailControl" placeholder="Email" />

    @if (isTouched() && emailControl.invalid) {
      <span class="error">Please enter a valid email</span>
    }
  `,
})
class EmailInputComponent {
  emailControl = new FormControl('', [Validators.required, Validators.email]);
  isTouched = useControlTouched(this.emailControl);
}

Parameters

Parameter	Type	Default	Description
control	AbstractControl	required	The control to check touched state for

Returns

Signal<boolean> - A readonly signal containing the touched state (true if interacted with)

Notes

• Works with FormControl, FormGroup, and FormArray
• Uses control.events (Angular's unified event stream) filtered to TouchedChangeEvent — not statusChanges, which does not emit on touched-state changes
• Returns true when markAsTouched() is called or the control loses focus (blur)
• Useful for showing validation errors only after user interaction

Source

import { Signal } from '@angular/core';
import { toSignal } from '@angular/core/rxjs-interop';
import { AbstractControl, TouchedChangeEvent } from '@angular/forms';
import { filter, map } from 'rxjs';

/**
 * Returns whether an AbstractControl has been touched (interacted with) as a signal.
 * The signal updates reactively whenever the control's touched state changes,
 * including when markAsTouched() or markAsUntouched() are called directly.
 * Works with FormControl, FormGroup, and FormArray.
 *
 * @param control - The AbstractControl to check touched state for
 * @returns A signal containing the touched state (true if interacted with)
 *
 * @example
 * ```typescript
 * @Component({
 *   template: `
 *     <input [formControl]="emailControl" />
 *     @if (isTouched() && emailControl.invalid) {
 *       <span>Please enter a valid email</span>
 *     }
 *   `
 * })
 * class MyComponent {
 *   emailControl = new FormControl('', Validators.email);
 *   isTouched = useControlTouched(this.emailControl);
 * }
 * ```
 */
export const useControlTouched = (control: AbstractControl): Signal<boolean> => {
  return toSignal(
    control.events.pipe(
      filter((event): event is TouchedChangeEvent => event instanceof TouchedChangeEvent),
      map((event) => event.touched),
    ),
    { initialValue: control.touched },
  ) as Signal<boolean>;
};