ISSUE-1: Implemented EntityToIdentifierTransformer

Author: raymondschouten

src/EntityToIdentifierTransformer.php

@@ -0,0 +1,129 @@
+<?php
+/**
+ * Copyright (c) 2017 DarkWeb Design
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+namespace DarkWebDesign\SymfonyAddon\Transformer;
+
+use Doctrine\Common\Persistence\ObjectManager;
+use Doctrine\Common\Util\ClassUtils;
+use Symfony\Component\Form\DataTransformerInterface;
+use Symfony\Component\Form\Exception\InvalidArgumentException;
+use Symfony\Component\Form\Exception\TransformationFailedException;
+
+/**
+ * Transforms between an identifier and a Doctrine entity.
+ *
+ * @author Raymond Schouten
+ *
+ * @since 2.3
+ */
+class EntityToIdentifierTransformer implements DataTransformerInterface
+{
+    /** @var \Doctrine\Common\Persistence\ObjectManager */
+    private $entityManager;
+
+    /** @var string */
+    private $className;
+
+    /** @var \Doctrine\Common\Persistence\ObjectRepository */
+    private $repository;
+
+    /** @var \Doctrine\Common\Persistence\Mapping\ClassMetadata */
+    private $metadata;
+
+    /**
+     * Constructor.
+     *
+     * @param \Doctrine\Common\Persistence\ObjectManager $entityManager
+     * @param string $className
+     *
+     * @throws \Symfony\Component\Form\Exception\InvalidArgumentException
+     */
+    public function __construct(ObjectManager $entityManager, $className)
+    {
+        $this->entityManager = $entityManager;
+        $this->className = $className;
+        $this->repository = $this->entityManager->getRepository($this->className);
+        $this->metadata = $this->entityManager->getClassMetadata($this->className);
+
+        if ($this->metadata->isIdentifierComposite) {
+            throw new InvalidArgumentException('Expected an entity with a single identifier.');
+        }
+    }
+
+    /**
+     * Transforms a value from the original representation to a transformed representation.
+     *
+     * @param object $value
+     *
+     * @return mixed
+     *
+     * @throws \Symfony\Component\Form\Exception\TransformationFailedException
+     */
+    public function transform($value)
+    {
+        if (null === $value) {
+            return null;
+        }
+
+        if (!is_object($value) || is_callable($value)) {
+            throw new TransformationFailedException('Expected an object.');
+        }
+
+        $class = ClassUtils::getClass($value);
+
+        if ($class !== $this->className) {
+            throw new TransformationFailedException(sprintf('Expected entity %s.', $this->className));
+        }
+
+        $identifierValues = $this->metadata->getIdentifierValues($value);
+
+        return reset($identifierValues);
+    }
+
+    /**
+     * Transforms a value from the transformed representation to its original representation.
+     *
+     * @param mixed $value
+     *
+     * @return object
+     *
+     * @throws \Symfony\Component\Form\Exception\TransformationFailedException
+     */
+    public function reverseTransform($value)
+    {
+        if (null === $value || '' === $value) {
+            return null;
+        }
+
+        if (!is_scalar($value)) {
+            throw new TransformationFailedException('Expected a scalar.');
+        }
+
+        $entity = $this->repository->find($value);
+
+        if (null === $entity) {
+            throw new TransformationFailedException(
+                sprintf('Entity %s with identifier "%s" not found.', $this->className, $value)
+            );
+        }
+
+        return $entity;
+    }
+}