Simplest form validation for flutter form widgets.
- Zero dependency
- Localization supported
- Extensible
- Well tested
- Open source
TextFormField(
validator: ValidationBuilder().email().maxLength(50).build(),
decoration: InputDecoration(labelText: 'Email'),
),
Add form_validator as dependency to your flutter project by adding this lines to pubspec.yaml.
dependencies:
form_validator: ">=0.1.1 <2.0.0"Then run flutter pub get to install required dependencies.
Check installation tab for more information
Import form_validator package to your dart widgets by writing:
import 'package:form_validator/form_validator.dart';Now you can use ValidationBuilder class to create validation logic. Here's simple validator that validates if input length is between 10 and 50 characters long.
final validate = ValidationBuilder().minLength(10).maxLength(50).build();
print(validate('test')); // Minimum length must be at least 10 characters
print(validate('Hello World')); // null, means value is correctYou can set global locale using ValidationBuilder.setLocale(String localeName)
or you can also define locale on ValidationBuilder({ String localeName }) constructor.
ValidationBuilder.setLocale('en');
// will use *en* localization
ValidationBuilder()
.minLength(5)
.build();
// will use *az* localization
ValidationBuilder(localeName: 'az')
.minLength(5)
.build();
// will display custom message
ValidationBuilder()
.minLength(5, 'Length < 5 😟')
.build();Validates if value length is not less than minLength.
Validates if value length is not more than maxLength.
Checks if value is an email address.
Checks if value is an phone number.
Note: This method might be changed in future.
Checks if value is correct IPv4 address.
Checks if value is correct IPv6 address.
Checks if value is correct url address.
Validates if value does matches regExp or not.
messageargument is required in this method.
Validates if value passes any of left and right validations. If value doesn't passes any error message from right validation will be displayed (If reverse set to true message from left validation will be displayed).
Example:
print(
ValidationBuilder().or(
(builder) => builder.email('not email'),
(builder) => builder.phone('not phone'),
)
.test('invalid')
); // not phone
print(
ValidationBuilder().or(
(builder) => builder.email('not email'),
(builder) => builder.phone('not phone'),
reverse: true,
)
.test('invalid')
); // not emailYou need to construct different instances for each validation.
final builder = ValidationBuilder().email();
TextFormField(
validator: builder.maxLength(50).build(),
),
TextFormField(
validator: builder.maxLength(20).build(),
),final validator1 = ValidationBuilder().email().maxLength(50).build();
final validator2 = ValidationBuilder().email().maxLength(20).build();
TextFormField(
validator: validator1,
),
TextFormField(
validator: validator2,
),Firstly you need to extend abstract FormValidatorLocale class.
import 'package:form_validator/form_validator.dart';
class MyValidationLocale extends FormValidatorLocale {
@override
String name() => "custom";
@override
String required() => "Field is required";
...
}PROTIP: You can copy a language file from /lib/src/i18n folder and modify messages as you want.
Then you can use your custom locale class as global or local validation locale.
// global locale
void main() {
ValidationBuilder.globalLocale = MyValidationLocale();
...
}
// local locale
final locale = MyValidationLocale();
build(BuildContext context) {
final emailValidator = ValidationBuilder(locale: locale)
.email()
.build();
...
}PROTIP: Feel free to add your locale to library by opening pull request TheMisir/form-validator to support library.
You can use dart extension methods to extend ValidationBuilder.
extension CustomValidationBuilder on ValidationBuilder {
password() => add((value) {
if (value == 'password') {
return 'Password should not "password"';
}
return null;
});
}
final validator = ValidationBuilder().password().build();If you would like to support this library you could translate messages to your own language.
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