fform_validator 1.0.0

fform_validator is a Flutter package that helps you to validate your form fields (optional).

fform_validator

• Features
• Installation
• Usage
  • Example
    • Methods
    • Example of Validating a Credit Card
    • Example of Validating an IP Address
    • Recommendation for use with the fform package
    • Example of a Custom Password Field
• Contributing
• License
• Contact

FFormValidator is a simple and lightweight Dart package for validating form inputs such as emails, URLs, IP addresses, credit card numbers, and more. It provides convenient validation methods to ensure your form data meets specific criteria without writing complex validation logic from scratch.

Features

• Validate if a string is non-empty (isRequired).
• Validate if a string is a valid email (isEmail).
• Validate if a string is a valid URL (isUrl).
• Validate if a string has a minimum or maximum length.
• Validate if a string is a valid IP address or IPv6 address.
• Validate if a string contains only numeric characters.
• Validate if a string is all lowercase or uppercase.
• Validate if a string contains special characters.
• Validate if a string is a valid credit card number (with optional formatting).

Installation

run the following command:

flutter pub add fform_validator

Usage

To use the FFormValidator class, simply create an instance with the string you want to validate and call the appropriate validation methods.

Example

import 'package:fform_validator/fform_validator.dart';

void main() {
  final validator = FFormValidator('hello');

  print(validator.isRequired); // true
  print(validator.isEmail); // false

  final emailValidator = FFormValidator('[e-mail]');
  print(emailValidator.isEmail); // true

  final urlValidator = FFormValidator('https://www.example.com');
  print(urlValidator.isUrl); // true
}

Methods

Method	Description
bool get isRequired	Returns true if the string is non-empty.
bool get isEmail	Returns true if the string is a valid email address.
bool get isUrl	Returns true if the string is a valid URL.
bool isMinLength(int length)	Returns true if the string is at least length characters long.
bool isMaxLength(int length)	Returns true if the string is at most length characters long.
bool isLength(int length)	Returns true if the string is exactly length characters long.
bool get isIp	Returns true if the string is a valid IPv4 address.
bool get isIpv6	Returns true if the string is a valid IPv6 address.
bool get isNumber	Returns true if the string contains only numeric characters.
bool get isHaveNumber	Returns true if the string have numeric characters.
bool get isFloat	Returns true if the string contains only numeric characters. not required with dot
bool get isHaveFloat	Returns true if the string have numeric characters. not required with dot
bool get isLowercase	Returns true if the string is in lowercase.
bool get isUppercase	Returns true if the string is in uppercase.
bool get isHaveSpecialChar	Returns true if the string contains any special characters.
bool isCreditCard({String space = ' '})	Returns true if the string is a valid credit card number. Can handle spaces.

Example of Validating a Credit Card

final cardValidator = FFormValidator('1234 5678 1234 5678');
print(cardValidator.isCreditCard()); // true

Example of Validating an IP Address

final ipValidator = FFormValidator('192.168.1.1');
print(ipValidator.isIp); // true

final ipv6Validator = FFormValidator('2001:0db8:85a3:0000:0000:8a2e:0370:7334');
print(ipv6Validator.isIpv6); // true

fform

Recommendation for use with the fform package

To create custom input fields with flexible validation, it is recommended to use the fform package in combination with your own validator, such as fform_validator. This allows you to check if a password field value meets requirements such as minimum length, special characters, and numbers, with detailed error output.

Example of a Custom Password Field

import 'package:fform/fform.dart';
import 'package:fform_validator/fform_validator.dart';

class PasswordValidationException extends FFormException {
  final bool isMinLengthValid;
  final bool isSpecialCharValid;
  final bool isNumberValid;

  PasswordValidationException({
    required this.isMinLengthValid,
    required this.isSpecialCharValid,
    required this.isNumberValid,
  });
  
  bool get isValid => isMinLengthValid && isSpecialCharValid && isNumberValid;
}

class PasswordField extends FFormField<String, PasswordValidationException> {
  PasswordField(String value) : super(value);

  @override
  PasswordValidationException? validator(String value) {
    final validator = FFormValidator(value);
    return PasswordValidationException(
      isMinLengthValid: validator.isMinLength(8),
      isSpecialCharValid: validator.isHaveSpecialChar,
      isNumberValid: validator.isHaveNumber,
    );
  }
}

Contributing

Contributions are welcome! Please submit a pull request or open an issue on GitHub if you find bugs or have feature suggestions.

1. Fork the repository.
2. Create a new branch.
3. Make your changes and commit.
4. Push the branch to your fork and submit a pull request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Contact

For any questions or feedback, feel free to reach out via GitHub issues.