Class FieldNodeState

packages/forms/signals/src/field/state.ts:21–195

 * status, as well as derived logical state.
 */
export class FieldNodeState {
  /**
   * Indicates whether this field has been touched directly by the user (as opposed to indirectly by
   * touching a child field).
   *
   * A field is considered directly touched when a user stops editing it for the first time (i.e. on blur)
   */
  private readonly selfTouched = signal(false);

  /**
   * Indicates whether this field has been dirtied directly by the user (as opposed to indirectly by
   * dirtying a child field).
   *
   * A field is considered directly dirtied if a user changed the value of the field at least once.
   */
  private readonly selfDirty = signal(false);

  /**
   * Marks this specific field as touched.
   */
  markAsTouched(): void {
    this.selfTouched.set(true);
  }

  /**
   * Marks this specific field as dirty.
   */
  markAsDirty(): void {
    this.selfDirty.set(true);
  }

  /**
   * Marks this specific field as not dirty.
   */
  markAsPristine(): void {
    this.selfDirty.set(false);
  }

  /**
   * Marks this specific field as not touched.
   */
  markAsUntouched(): void {
    this.selfTouched.set(false);
  }

  /** The {@link FormField} directives that bind this field to a UI control. */
  readonly formFieldBindings = signal<readonly FormField<unknown>[]>([]);

  constructor(private readonly node: FieldNode) {}

  /**
   * Whether this field is considered dirty.
   *
   * A field is considered dirty if one of the following is true:
   *  - It was directly dirtied and is interactive
   *  - One of its children is considered dirty
   */
  readonly dirty: Signal<boolean> = computed(() => {