Method patchValue

packages/forms/src/model/form_group.ts:480–504

* Patches the value of the `FormGroup`. It accepts an object with control * names as keys, and does its best to match the values to the correct controls * in the group. * * It accepts both super-sets and sub-sets of the group without throwing an error. * * @usageNotes * ### Patc

(
    value: ɵFormGroupValue<TControl>,
    options: {
      onlySelf?: boolean;
      emitEvent?: boolean;
    } = {},
  )

   * the {@link AbstractControl#updateValueAndValidity updateValueAndValidity} method.
   */
  override patchValue(
    value: ɵFormGroupValue<TControl>,
    options: {
      onlySelf?: boolean;
      emitEvent?: boolean;
    } = {},
  ): void {
    // Even though the `value` argument type doesn't allow `null` and `undefined` values, the
    // `patchValue` can be called recursively and inner data structures might have these values, so
    // we just ignore such cases when a field containing FormGroup instance receives `null` or
    // `undefined` as a value.
    if (value == null /* both `null` and `undefined` */) return;
    (Object.keys(value) as Array<keyof TControl>).forEach((name) => {
      const existingControl = this._find(name as string);
      if (existingControl) {
        existingControl.patchValue(
          /* Guaranteed to be present, due to the outer forEach. */ value[
            name as keyof ɵFormGroupValue<TControl>
          ]!,
          {onlySelf: true, emitEvent: options.emitEvent},
        );
      }
    });
    this.updateValueAndValidity(options);
  }

  /**
   * Resets the `FormGroup`, marks all descendants `pristine` and `untouched` and sets