form_builder_thai_provinces

A flutter_form_builder field for Thai province/district/subdistrict address selection — cascading dropdowns or a type-ahead field, with full two-way FormBuilder value synchronisation.

This is a thin adapter around thai_provinces_flutter. It carries the flutter_form_builder dependency so the core thai_provinces_flutter package stays dependency-free.

Install

dependencies:
  form_builder_thai_provinces: ^0.1.0

A single import gives you everything (the core widgets, ThaiAddressSelection, ThaiAddressController, ThaiAddressLanguage and ThaiAddressValidators are all re-exported):

import 'package:form_builder_thai_provinces/form_builder_thai_provinces.dart';

Usage

FormBuilderThaiAddress is a FormBuilderField<ThaiAddressSelection>, so it plugs straight into a FormBuilder and works with saveAndValidate(), patchValue(), reset() and fields['name'].value.

Cascading dropdowns (default), with a validator

final formKey = GlobalKey<FormBuilderState>();

FormBuilder(
  key: formKey,
  child: FormBuilderThaiAddress(
    name: 'address',
    validator: ThaiAddressValidators.required(),
    // mode: FormBuilderThaiAddressMode.cascading, // default
    // language: ThaiAddressLanguage.thai,         // default
    // showPostcode: true,                         // default
  ),
);

// On submit:
if (formKey.currentState!.saveAndValidate()) {
  final ThaiAddressSelection? value =
      formKey.currentState!.value['address'] as ThaiAddressSelection?;
  print(value?.format());
}

Type-ahead (autocomplete) mode

FormBuilderThaiAddress(
  name: 'address',
  mode: FormBuilderThaiAddressMode.autocomplete,
  validator: ThaiAddressValidators.required(),
);

Driving the field from the form

// Pre-fill / update programmatically — the UI follows:
formKey.currentState!.patchValue({
  'address': ThaiAddressSelection.fromCodes(subdistrictCode: 100101),
});

// Reset back to the initialValue:
formKey.currentState!.reset();

How it works

FormBuilderThaiAddress wraps a ThaiAddressPicker (or ThaiAddressAutocompleteField) in a public FormBuilderField. An internal ThaiAddressController is kept in lock-step with the field value in both directions: picker changes call field.didChange(...), and external form changes (reset()/patchValue()) are pushed back into the controller. The current validation error is surfaced in the field.

License

MIT © MaIII (ultramcu)