FieldValidatorFlutter
A centralized, reusable, and easy-to-use field validation utility class for Flutter apps.
FieldValidatorFlutter provides a collection of static validation functions to validate common form fields like email, phone number, password, username, name, URL, tax percentage, quantity, OTP, postal code, and more.
✨ Features
✅ Centralized validation logic
✅ Covers most common form fields
✅ Ready-to-use static functions
✅ Customizable parameters (length limits, field names, etc.)
✅ Works with Flutter TextFormField validators
📦 Installation
Add the latest version to your pubspec.yaml:
dependencies:
field_validator_flutter: ^1.0.0
Use in a Form
TextFormField(
decoration: InputDecoration(labelText: 'Email'),
validator: (value) => FieldValidatorFlutter.email(value),
),
Supported Validators & Custom Parameters
| Validator Function | Purpose | Customizable Parameters |
|---|---|---|
firstName() |
Validate first name | lengthLimit (min length) |
lastName() |
Validate last name | lengthLimit (min length) |
username() |
Validate username (alphanumeric, underscores, dots) | — |
email() |
Validate email format | — |
phone() |
Validate phone number (7-15 digits, optional +) | — |
mobile() |
Validate mobile number (custom length) | length (exact length) |
password() |
Validate strong password (uppercase, lowercase, number, special char, min 8 chars) | — |
confirmPassword() |
Validate password confirmation | Pass password string for match check |
url() |
Validate website URL | — |
tax() |
Validate tax percentage (0 - 100) | — |
quantity() |
Validate quantity (positive integer) | — |
postalCode() |
Validate postal code (4-10 digits) | — |
otp() |
Validate OTP (custom length, numeric) | length (default 6 digits) |
message() |
Validate message (required, min length) | lengthLimit |
address() |
Validate address (required, min length) | lengthLimit |
required() |
Validate required field | fieldName |
numeric() |
Validate numeric input | fieldName |
positiveNumber() |
Validate positive number | fieldName |
length() |
Validate string length (min/max) | min, max, fieldName |
🧩 Customization
Many validator functions allow optional parameters like lengthLimit, fieldName, length to customize error messages and validation rules.
FieldValidatorFlutter.mobile(value, length: 8); // mobile number with 8 digits
Authors
License
Use freely in your commercial or personal Flutter projects.
🤝 Contributions
Feel free to fork, improve, or add more validators! Pull requests are welcome.