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flutter form async validation

Ben answered on April 9, 2024 Popularity 2/10 Helpfulness 1/10

answer flutter form async validation

flutter form async validation

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import 'dart:async';
import 'package:flutter/material.dart';
import 'package:form_bloc/form_bloc.dart';
import 'package:flutter_form_bloc/flutter_form_bloc.dart';

void main() => runApp(MaterialApp(home: HomeScreen()));

class HomeScreen extends StatefulWidget {
  HomeScreen({Key key}) : super(key: key);

  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  TextFieldBloc _phoneFieldBloc;

  StreamSubscription<TextFieldBlocState> _textFieldBlocSubscription;

  @override
  void initState() {
    super.initState();
    _phoneFieldBloc = TextFieldBloc(
      asyncValidatorDebounceTime: Duration(milliseconds: 300),
      asyncValidators: [_validatePhone],
    );

    _textFieldBlocSubscription = _phoneFieldBloc.state.listen((state) {
      if (state.isValid) {
        // Print the value of the _textFieldBloc when has a valid value
        print(state.value);
      }
    });
  }

  @override
  void dispose() {
    _phoneFieldBloc.dispose();
    _textFieldBlocSubscription.cancel();
    super.dispose();
  }

  Future<String> _validatePhone(String number) async {
    // Fake phone async validator
    await Future<void>.delayed(Duration(milliseconds: 200));
    if (number.length > 4 && number.length < 9) {
      return 'Your phone number is not valid';
    }
    return null;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: TextFieldBlocBuilder(
          textFieldBloc: _phoneFieldBloc,
          suffixButton: SuffixButton.circularIndicatorWhenIsAsyncValidating,
          decoration: InputDecoration(labelText: 'Phone number'),
          keyboardType: TextInputType.phone,
        ),
      ),
    );
  }
}

Popularity 2/10 Helpfulness 1/10 Language whatever

Source: stackoverflow.com

Tags: flutter validation whatever

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Contributed on Apr 09 2024

Ben

0 Answers Avg Quality 2/10

flutter form async validation

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