Validation
A validation library for PHP that uses the notification pattern.
Table of contents
Requirements
- PHP 7.2+ or 8.0+
Installation
composer require selective/validationUsage
A notification is a collection of errors
In order to use a notification, you have to create the ValidationResult object. A ValidationResult can be really
simple:
<?php
use Selective\Validation\Exception\ValidationException;
use Selective\Validation\ValidationResult;
$validationResult = new ValidationResult();
if (empty($data['username'])) {
$validationResult->addError('username', 'Input required');
}You can now test the ValidationResult and throw an exception if it contains errors.
<?php
if ($validationResult->fails()) {
throw new ValidationException('Please check your input', $validationResult);
}Validating form data
Login example:
<?php
use Selective\Validation\Exception\ValidationException;
use Selective\Validation\ValidationResult;
// ...
// Get all POST values
$data = (array)$request->getParsedBody();
$validation = new ValidationResult();
// Validate username
if (empty($data['username'])) {
$validation->addError('username', 'Input required');
}
// Validate password
if (empty($data['password'])) {
$validation->addError('password', 'Input required');
}
// Check validation result
if ($validation->fails()) {
// Trigger error response (see validation middleware)
throw new ValidationException('Please check your input', $validation);
}Validating JSON
Validating a JSON request works like validating form data, because in PHP it's just an array from the request object.
<?php
use Selective\Validation\ValidationResult;
// Fetch json data from request as array
$jsonData = (array)$request->getParsedBody();
$validation = new ValidationResult();
// ...
if ($validation->fails()) {
throw new ValidationException('Please check your input', $validation);
}In vanilla PHP you can fetch the JSON request as follows:
<?php
$jsonData = (array)json_decode(file_get_contents('php://input'), true);
// ...Regex
The Selective\Validation\Regex\ValidationRegex class allows you to validate if
a given string conforms a defined regular expression.
Example usage:
use Selective\Validation\Factory\CakeValidationFactory;
use Selective\Validation\Regex\ValidationRegex;
// ...
$data = [ /* ... */ ];
$validationFactory = new CakeValidationFactory();
$validator = $validationFactory->createValidator();
$validator
->regex('id', ValidationRegex::ID, 'Invalid')
->regex('country', ValidationRegex::COUNTRY_ISO_2, 'Invalid country')
->regex('date_of_birth', ValidationRegex::DATE_DMY, 'Invalid date format');Middleware
The ValidationExceptionMiddleware catches the ValidationException and converts it into a nice JSON response.
Slim 4 integration
Insert a container definition for ValidationExceptionMiddleware::class:
<?php
use Psr\Container\ContainerInterface;
use Psr\Http\Message\ResponseFactoryInterface;
use Selective\Validation\Encoder\JsonEncoder;
use Selective\Validation\Middleware\ValidationExceptionMiddleware;
use Selective\Validation\Transformer\ErrorDetailsResultTransformer;
use Slim\App;
use Slim\Factory\AppFactory;
// ...
return [
ValidationExceptionMiddleware::class => function (ContainerInterface $container) {
$factory = $container->get(ResponseFactoryInterface::class);
return new ValidationExceptionMiddleware(
$factory,
new ErrorDetailsResultTransformer(),
new JsonEncoder()
);
},
ResponseFactoryInterface::class => function (ContainerInterface $container) {
$app = $container->get(App::class);
return $app->getResponseFactory();
},
App::class => function (ContainerInterface $container) {
AppFactory::setContainer($container);
return AppFactory::create();
},
// ...
];Add the ValidationExceptionMiddleware into your middleware stack:
<?php
use Selective\Validation\Middleware\ValidationExceptionMiddleware;
use Slim\Factory\AppFactory;
require_once __DIR__ . '/../vendor/autoload.php';
$app = AppFactory::create();
// ...
$app->add(ValidationExceptionMiddleware::class);
// ...
$app->run();Usage in Slim
<?php
use Selective\Validation\ValidationException;
use Selective\Validation\ValidationResult;
$validation = new ValidationResult();
// Validate username
if (empty($data->username)) {
$validation->addError('username', 'Input required');
}
// Check validation result
if ($validation->fails()) {
// Trigger the validation middleware
throw new ValidationException('Please check your input', $validation);
}Validators
You can combine this library with a validator that is doing the actual validation of your input data.
The converter pattern makes it easy to map instances of one class into instances of another class.
CakePHP Validator
The cakephp/validation library provides features to build validators that can validate arbitrary arrays of data with ease.
Installation
composer require cakephp/validation
Usage
The Cake\Validation\Validator::validate() method returns a non-empty array when
there are validation failures. The list of errors then can be converted into
a ValidationResult using the Selective\Validation\Factory\CakeValidationFactory
or Selective\Validation\Converter\CakeValidationConverter.
For example, if you want to validate a login form you could do the following:
use Selective\Validation\Factory\CakeValidationFactory;
use Selective\Validation\Exception\ValidationException;
// ...
// Within the Action class: fetch the request data, e.g. from a JSON request
$data = (array)$request->getParsedBody();
// Within the Application Service class: Do the validation
$validationFactory = new CakeValidationFactory();
$validator = $validationFactory->createValidator();
$validator
->notEmptyString('username', 'Input required')
->notEmptyString('password', 'Input required');
$validationResult = $validationFactory->createValidationResult(
$validator->validate($data)
);
if ($validationResult->fails()) {
throw new ValidationException('Please check your input', $validationResult);
}Please note: The CakeValidationFactory should be injected via constructor.
Read more: https://odan.github.io/2020/10/18/slim4-cakephp-validation.html
Transformer
If you want to implement a custom response data structure,
you can implement a custom transformer against the
\Selective\Validation\Transformer\ResultTransformerInterface interface.
Example
<?php
namespace App\Transformer;
use Selective\Validation\Exception\ValidationException;
use Selective\Validation\Transformer\ResultTransformerInterface;
use Selective\Validation\ValidationResult;
final class MyValidationTransformer implements ResultTransformerInterface
{
public function transform(
ValidationResult $validationResult,
ValidationException $exception = null
): array {
// Implement your own data structure for the response
// ...
return [];
}
}License
The MIT License (MIT). Please see License File for more information.