Add symfony validator support

Author: odan

README.md

@@ -234,11 +234,11 @@ final class MyValidationTransformer implements ResultTransformerInterface
 }
 ```
 
-## Validator integration
+## Validators
 
 You can combine this library with a validator that is doing the actual validation of your input data.
 
-### Integration with CakePHP Validation 
+### CakePHP Validator
 
 The [cakephp/validation](https://github.com/cakephp/validation) library provides features to 
 build validators that can validate arbitrary arrays of data with ease. 
@@ -281,28 +281,87 @@ $validator
 $validationResult = CakeValidatorFactory::createValidationResult($validator->validate($formData));
 
 // Optional: Do more complex validation and append it to the validation result
-if (!$this->existsEmailInDatabase($formData['email'])) {
-    $validationResult->addError('email', 'E-Mail already exists');
+if ($this->existsUsername($formData['username'])) {
+    $validationResult->addError('username', 'Username is already taken);
 }
 
 if ($validationResult->isFailed()) {
     throw new ValidationException('Validation failed. Please check your input.', $validationResult);
 }
 ```
 
+### Symfony Validator
+
+**Installation**
+
+```
+composer require symfony/validator
+```
+
 **Usage**
 
 ```php
 <?php
-$validator = $this->validationFactory->createValidator();
 
-// ...
+use Cake\Validation\Validator;
+use Selective\Validation\Exception\ValidationException;
+use Selective\Validation\Regex\ValidationRegex;
+use Selective\Validation\Factory\SymfonyValidatorFactory;
+use Symfony\Component\Validator\Constraints as Assert;
+use Symfony\Component\Validator\ConstraintViolation;
+use Symfony\Component\Validator\Validation;
+
+// Note: This is just an example. Don't use the $request object within the domain layer.
+$formData = (array)$request->getParsedBody();
 
-$validationResult = $this->validationFactory->createErrorCollector()
-    ->addErrors($validator->validate($form));
+// Create a symfony validator instance
+$validator = Validation::createValidator();
+
+// Add rules
+$constraint = new Assert\Collection(
+    [
+        'first_name' => new Assert\NotBlank(['message' => 'Input required']),
+        'last_name' => new Assert\NotBlank(['message' => 'Input required']),
+        'mobile' => new Assert\Optional(
+            [
+                new Assert\Regex(
+                    [
+                        'pattern' => ValidationRegex::PHONE_NUMBER,
+                        'message' => 'Invalid',
+                    ]
+                ),
+            ]
+        ),
+        'comment' => new Assert\Optional(
+            [
+                new Assert\Length(['max' => 255, 'maxMessage' => 'Too long']),
+            ]
+        ),
+        'email' => new Assert\Optional(
+            [
+                new Assert\Email(
+                    [
+                        'message' => 'Invalid',
+                    ]
+                ),
+            ]
+        )
+    ]
+);
+
+$constraint->missingFieldsMessage = 'Input required';
+$violations = $validator->validate($formData, $constraint);
+
+// Convert violations to ValidationResult
+$validationResult = SymfonyValidatorFactory::createValidationResult($violations);
+
+// Optional: Do more complex validation and append it to the validation result
+if ($this->existsUsername($formData['username'])) {
+    $validationResult->addError('username', 'Username is already taken');
+}
 
 if ($validationResult->isFailed()) {
-   // ...
+    throw new ValidationException(__('Please check your input'), $validationResult);
 }
 ```
 

composer.json

@@ -23,7 +23,8 @@
         "phpunit/phpunit": "^7.0|^8.0",
         "relay/relay": "^2.0",
         "slim/psr7": "^1",
-        "squizlabs/php_codesniffer": "^3.4"
+        "squizlabs/php_codesniffer": "^3.4",
+        "symfony/validator": "^5.1"
     },
     "scripts": {
         "test": "phpunit --configuration phpunit.xml",

src/Factory/SymfonyValidatorFactory.php

@@ -0,0 +1,39 @@
+<?php
+
+namespace Selective\Validation\Factory;
+
+use Selective\Validation\ValidationResult;
+use Symfony\Component\Validator\ConstraintViolation;
+use Symfony\Component\Validator\ConstraintViolationList;
+
+/**
+ * Symfony validation error collector.
+ */
+final class SymfonyValidatorFactory
+{
+    /**
+     * Create validation result from array with errors.
+     *
+     * @param ConstraintViolationList $violations The validation errors
+     * @param ValidationResult|null $result The result
+     *
+     * @return ValidationResult The result
+     */
+    public static function createValidationResult(
+        ConstraintViolationList $violations,
+        ValidationResult $result = null
+    ): ValidationResult {
+        if ($result === null) {
+            $result = new ValidationResult();
+        }
+
+        /** @var ConstraintViolation $violation */
+        foreach ($violations as $violation) {
+            $field = $violation->getPropertyPath();
+            $field = str_replace(']', '', str_replace('[', '', str_replace('][', '.', $field)));
+            $result->addError($field, $violation->getMessage());
+        }
+
+        return $result;
+    }
+}