DoctrineExtensions/lib/Gedmo/Mapping/ExtensionMetadataFactory.php

<?php

namespace Gedmo\Mapping;

use Doctrine\Common\Persistence\ObjectManager,
    Doctrine\Common\Persistence\Mapping\ClassMetadata;

/**
 * The extension metadata factory is responsible for extension driver
 * initialization and fully reading the extension metadata
 * 
 * @author Gediminas Morkevicius <gediminas.morkevicius@gmail.com>
 * @package Gedmo.Mapping
 * @subpackage ExtensionMetadataFactory
 * @link http://www.gediminasm.org
 * @license MIT License (http://www.opensource.org/licenses/mit-license.php)
 */
class ExtensionMetadataFactory
{
    /**
     * Extension driver
     * @var Gedmo\Mapping\Driver
     */
    protected $driver;
    
    /**
     * Object manager, entity or document
     * @var object
     */
    private $objectManager;
    
    /**
     * Extension namespace
     * 
     * @var string
     */
    private $extensionNamespace;
    
    /**
     * Initializes extension driver
     * 
     * @param ObjectManager $objectManager
     * @param string $extensionNamespace
     */
    public function __construct(ObjectManager $objectManager, $extensionNamespace)
    {
        $this->objectManager = $objectManager;
        $this->extensionNamespace = $extensionNamespace;
        $omDriver = $objectManager->getConfiguration()->getMetadataDriverImpl();
        $this->driver = $this->getDriver($omDriver);
    }
    
    /**
     * Reads extension metadata
     * 
     * @param ClassMetadata $meta
     * @return array - the metatada configuration
     */
    public function getExtensionMetadata(ClassMetadata $meta)
    {
        if ($meta->isMappedSuperclass) {
            return; // ignore mappedSuperclasses for now
        }
        $config = array();
        // collect metadata from inherited classes
        foreach (array_reverse(class_parents($meta->name)) as $parentClass) {
            // read only inherited mapped classes
            if ($this->objectManager->getMetadataFactory()->hasMetadataFor($parentClass)) {
                $this->driver->readExtendedMetadata($this->objectManager->getClassMetadata($parentClass), $config);
            }
        }
        $this->driver->readExtendedMetadata($meta, $config);
        $this->driver->validateFullMetadata($meta, $config);
        if ($config) {
            // cache the metadata
            $cacheId = self::getCacheId($meta->name, $this->extensionNamespace);
            if ($cacheDriver = $this->objectManager->getMetadataFactory()->getCacheDriver()) {
                $cacheDriver->save($cacheId, $config, null);
            }
        }
        return $config;
    }
    
    /**
     * Get the cache id
     * 
     * @param string $className
     * @param string $extensionNamespace
     * @return string
     */
    public static function getCacheId($className, $extensionNamespace)
    {
        return $className . '\\$' . strtoupper(str_replace('\\', '_', $extensionNamespace)) . '_CLASSMETADATA';
    }
    
    /**
     * Get the extended driver instance which will
     * read the metadata required by extension
     * 
     * @param object $omDriver
     * @throws DriverException if driver was not found in extension
     * @return Gedmo\Mapping\Driver
     */
    private function getDriver($omDriver)
    {
        $driver = null;
        $className = get_class($omDriver);
        $driverName = substr($className, strrpos($className, '\\') + 1);
        if ($driverName == 'DriverChain') {
            $driver = new Driver\Chain();
            foreach ($omDriver->getDrivers() as $namespace => $nestedOmDriver) {
                $driver->addDriver($this->getDriver($nestedOmDriver), $namespace);
            }
        } else {
            $driverName = substr($driverName, 0, strpos($driverName, 'Driver'));
            // create driver instance
            $driverClassName = $this->extensionNamespace . '\Mapping\Driver\\' . $driverName;
            if (!class_exists($driverClassName)) {
                // @TODO: implement XML driver also
                $driverClassName = $this->extensionNamespace . '\Mapping\Driver\Annotation';
                if (!class_exists($driverClassName)) {
                    throw new \Gedmo\Exception\RuntimeException("Failed to fallback to annotation driver: ({$driverClassName}), extension driver was not found.");
                }
            }
            $driver = new $driverClassName();
            if ($driver instanceof \Gedmo\Mapping\Driver\File) {
                $driver->setPaths($omDriver->getPaths());
            }
        }
        return $driver;
    }
}