updateValue method

@override void updateValue(List<T?>? value, { bool updateParent = true, bool emitEvent = true, })

Sets the value of the FormArray.

The value argument is a collection that matches the structure of the control.

When updateParent is true or not supplied (the default) each change affects this control and its parent, otherwise only affects to this control.

When emitEvent is true or not supplied (the default), both the statusChanges and valueChanges emit events with the latest status and value when the control is reset. When false, no events are emitted.

Example:

final array = FormArray([
  FormControl(),
  FormControl(),
]);

print(array.value); // outputs: [null, null]

array.updateValue(['John', 'Doe']);
print(array.value); // outputs: ['John', 'Doe']

Implementation

@override
void updateValue(
  List<T?>? value, {
  bool updateParent = true,
  bool emitEvent = true,
}) {
  for (var i = 0; i < _controls.length; i++) {
    if (value == null || i < value.length) {
      _controls[i].updateValue(
        value?.elementAt(i),
        updateParent: false,
        emitEvent: emitEvent,
      );
    }
  }

  if (value != null && value.length > _controls.length) {
    final newControls =
        value
            .toList()
            .asMap()
            .entries
            .where((entry) => entry.key >= _controls.length)
            .map((entry) => FormControl<T>(value: entry.value))
            .toList();

    addAll(newControls, updateParent: updateParent, emitEvent: emitEvent);
  } else {
    updateValueAndValidity(updateParent: updateParent, emitEvent: emitEvent);
  }
}