Flutter TextFormField event examples

main.dart

// ignore_for_file: annotate_overrides
// ignore_for_file: prefer_const_constructors
// ignore_for_file: prefer_const_literals_to_create_immutables
// ignore_for_file: unused_local_variable
// ignore_for_file: library_private_types_in_public_api
// ignore_for_file: unused_field

import 'package:flutter/material.dart';

const Color darkBlue = Color.fromARGB(255, 18, 32, 47);

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        body: Center(
          child: Blah(),
        ),
      ),
    );
  }
}

class Blah extends StatefulWidget {
  _BlahState createState() => _BlahState();
}

class _BlahState extends State<Blah> {
  var onValue = <String>[];
  final _formKey = GlobalKey<FormState>();

  Widget build(BuildContext context) {
    return Form(
      key: _formKey,
      child: Column(
        children: [
          Text('TextFormField'),
          Text('Interactive view of events'),
          Text(''),
          Text('onFieldSubmitted: press return on web'),
          Text('onSaved: press button (calls _formKey.currentState.save())'),
          Text('onChanged: change text'),
          Text('onEditingComplete: press return on web'),
          Text(
              'More: https://stackoverflow.com/questions/63690311/flutter-textfield-difference-between-onedittingcomplete-and-onsubmitted'),
          Text(' '),
          TextFormField(
            onFieldSubmitted: (x) =>
                setState(() => onValue.insert(0, "onFieldSubmitted")),
            onSaved: (x) => setState(() => onValue.insert(0, "onSaved")),
            onChanged: (x) => setState(() => onValue.insert(0, "onChanged")),
            onEditingComplete: () =>
                setState(() => onValue.insert(0, "onEditingComplete")),
          ),
          ElevatedButton(
            child: Text('Click me'),
            onPressed: () {
              if (_formKey.currentState!.validate()) {
                _formKey.currentState!.save();
                print('valid');
              }
            },
          ),
          ...onValue.map((x) => Text(x)),
        ],
      ),
    );
  }
}