A simple form validation library for Flutter.
class UserFormModel {
final String firstName;
final String lastName;
UserFormModel({
required this.firstName,
required this.lastName,
});
}
class MyPage extends StatelessWidget {
@override
build(context) {
return FormBuilder(
initialFormData: UserFormModel(firstName: 'John', lastName: ''),
builder: (context, formData, controller) {
final UserFormModel(:firstName, :lastName) = formData;
return Column(
children: [
Validation(
valid: firstName.isNotEmpty,
child: TextFormField(
initialValue: firstName,
decoration: const InputDecoration(labelText: 'First name'),
onChanged: (value) => controller.setForm(
formData.copyWith(firstName: value),
),
),
),
Validation(
valid: lastName.isNotEmpty,
child: TextFormField(
initialValue: lastName,
decoration: const InputDecoration(labelText: 'Last name'),
onChanged: (value) => controller.setForm(
formData.copyWith(lastName: value),
},
),
),
ElevatedButton(
child: Text('Submit'),
onPress: () {
if (controller.validate()) {
// Submit form
}
}
)
],
);
}
}
All validation widgets animate errors as shown below:
Field animations can be customized using the Validation.childAnimationBuilder
and Validation.errorAnimationBuilder
builders.
Fields can be labeled as optional using the Validation.required
field.
import 'package:flutter/material.dart';
import 'package:formality/formality.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
@override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: const Text('Formality Example'),
),
body: MyPage(),
),
);
}
}
class UserFormModel {
final String name;
final String description;
UserFormModel({
required this.name,
required this.description,
});
UserFormModel copyWith({String? name, String? description}) {
return UserFormModel(
name: name ?? this.name,
description: description ?? this.description,
);
}
}
class MyPage extends StatelessWidget {
@override
Widget build(BuildContext context) {
return Center(
child: FractionallySizedBox(
widthFactor: 0.7, // Limits the form width to 70% of the screen width
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: [
Padding(
padding: const EdgeInsets.all(16.0),
child: FormBuilder(
initialFormData: UserFormModel(
name: 'John Smith',
description: '',
),
builder: (context, formData, controller) {
final UserFormModel(:name, :description) = formData;
return Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Validation(
valid: name.isNotEmpty,
error: const Text("Name",
style: TextStyle(color: Colors.red),),
required: false,
child: TextFormField(
initialValue: name,
decoration: const InputDecoration(labelText: 'Name'),
onChanged: (value) => controller.setForm(
formData.copyWith(name: value),
),
),
),
const SizedBox(height: 16.0),
Validation(
valid: description.isNotEmpty,
error: const Text(
'Description cannot be empty',
style: TextStyle(color: Colors.red),
),
child: TextFormField(
initialValue: description,
decoration: const InputDecoration(
labelText: 'Description',
),
onChanged: (value) {
controller.setForm(
formData.copyWith(description: value),
);
},
),
),
const SizedBox(height: 24.0),
ElevatedButton(
child: const Text('Submit'),
onPressed: () {
if (controller.validate()) {
// Add your form submission logic here
print('Form is valid and submitted');
}
},
),
],
);
},
),
),
],
),
),
);
}
}