[Feature Request] Can make the validator function become a async function?

[cogivn]

Hi,

Thank you for create an awesome package for flutter developer.

I am facing the problem is try to verify the otp code from server side but now the Pinput's validator only accept synchronize function
So, I open a ticket to request new feature that validator field can receive a async function or new mechanism to verify the OTP code from server side.

Pinput.builder(
                length: 6,
                controller: controller,
                focusNode: focusNode,
                autofocus: true,
                forceErrorState: state.status.isError,
                crossAxisAlignment: CrossAxisAlignment.center,
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                onCompleted: context.read<SmsCubit>().verify,
                onChanged: context.read<SmsCubit>().inputting,
                hapticFeedbackType: HapticFeedbackType.lightImpact,
                pinputAutovalidateMode: PinputAutovalidateMode.disabled,
                validator: (pin) async => verifyFromServer(pin),
                separatorBuilder: (_) => const SizedBox(width: 1),
                builder: (_, pinState) {
                  return _PinItem(state: pinState);
                },
              ),

[andrijailic]

I got here for similar problem, but it seems like there is a workaround -> #136.

You can supply onCompleted with async function and then, if validation on server fails, force this widget to go in error sate. I guess you should also set an errorText in that case and completely omit validator field.

I am not that happy with this solution (asyncValidator would be more elegant), but hey - it is what it is :)

[Tkko]

Hey, The Form widget which is the default way of creating forms in Flutter doesn't support async validator, so I have these options:

1. Remove support for validating Pinput by Form and make the validator method async
2. Create a new PinputForm widget which I don't like because more code = more confusion, more issue
3. Use forceErrorState to show the error message anytime you want, you can use bloc, riverpod etc and it isn't as painful as other options.