README

KetPHP Validator is a lightweight and highly typed validation library.

Opportunities

• Validation of values and objects
• PHP 8 Attributes support
• Extensible validation rules
• Clear error model (Result/Violation)
• Optional stop at the first error
• No dependencies

The library is suitable for validating DTOs, Form Objects, Request objects, and any input data.

Supported rules

Installation

Install via Composer:

composer require ket-php/validator

Usage

Validation of the value

use KetPHP\Validator\Validator;
use KetPHP\Validator\Annotation\Rule\MaxLength;
use KetPHP\Validator\Annotation\Rule\NotBlank;

$result = Validator::create('Hello world')->add(new NotBlank())->add(new MaxLength(5))->validate(); // returned Result

if ($result->isValid() === false) {
    foreach ($result->all() as $violation) {
        echo $violation->getMessage();
        print_r($violation->getParams());
    }
}

Validation of the object via attributes

Object:

use KetPHP\Validator\Annotation\Rule\Attribute\MaxLength;
use KetPHP\Validator\Annotation\Rule\Attribute\NotBlank;
use KetPHP\Validator\Annotation\Rule\Attribute\Range;

final class UserDto
{
    #[NotBlank]
    #[MaxLength(50)]
    public string $name;

    #[Range(min: 18, max: 99)]
    public int $age;
}

Example:

use KetPHP\Validator\Validator;
use KetPHP\Validator\Context\Result;

$user = new UserDto();
$user->name = '';
$user->age = 15;

$result = Validator::of($user); // returned UserDto (if valid) or Result (if invalid)

if ($result instanceof Result) {
    foreach ($result->all() as $violation) {
        echo $violation->getMessage();
        print_r($violation->getParams());
    }
}

Optional (nullable values)

Example:

use KetPHP\Validator\Annotation\Rule\Optional;
use KetPHP\Validator\Annotation\Rule\MaxLength;

$rule = new Optional(new MaxLength(10));

Attribute:

#[Optional(new MaxLength(10))]
public ?string $comment;

Error model

new Violation(
    message: 'Max length is {max}',             // string
    code: 'max_length',                         // string|int
    params: ['max' => 10, 'property' => 'name'] // array
);

Result:

$result->isValid(); // bool
$result->all();     // Violation[]

Creating your own rule

Rule

use KetPHP\Validator\Common\ValidationRuleInterface;
use KetPHP\Validator\Context\Violation;

final class StartsWithA implements ValidationRuleInterface
{

    public function validate(mixed $value): ?Violation
    {
        if (str_starts_with($value, 'A') === false) {
            return new Violation('Value must start with letter A', 'starts_with_a');
        }

        return null;
    }
}

Attribute

use KetPHP\Validator\Annotation\Rule\Attribute\Rule;
use Attribute;

#[Attribute(Attribute::TARGET_PROPERTY | Attribute::IS_REPEATABLE)]
final class StartsWithA extends Rule
{

    public function __construct()
    {
        parent::__construct(\Your\App\StartsWithA::class);
    }
}

Using

Rule:

$rule = new StartsWithA();
$rule->validate('Architecture');     // null
$rule->validate('Non Architecture'); // Violation

Attribute:

use KetPHP\Validator\Annotation\Rule\Attribute\Rule;
use Your\App\StartsWithA;

#[StartsWithA]              // With your attribute
#[Rule(StartsWithA::class)] // Without your attribute
public string $code;