Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Component\Discovery;
Chris@0: 
Chris@0: use Drupal\Component\FileSystem\RegexDirectoryIterator;
Chris@0: use Drupal\Component\Serialization\Exception\InvalidDataTypeException;
Chris@0: use Drupal\Component\Serialization\Yaml;
Chris@0: use Drupal\Component\FileCache\FileCacheFactory;
Chris@0: 
Chris@0: /**
Chris@0:  * Discovers multiple YAML files in a set of directories.
Chris@0:  */
Chris@0: class YamlDirectoryDiscovery implements DiscoverableInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * Defines the key in the discovered data where the file path is stored.
Chris@0:    */
Chris@0:   const FILE_KEY = '_discovered_file_path';
Chris@0: 
Chris@0:   /**
Chris@0:    * An array of directories to scan, keyed by the provider.
Chris@0:    *
Chris@0:    * The value can either be a string or an array of strings. The string values
Chris@0:    * should be the path of a directory to scan.
Chris@0:    *
Chris@0:    * @var array
Chris@0:    */
Chris@0:   protected $directories = [];
Chris@0: 
Chris@0:   /**
Chris@0:    * The suffix for the file cache key.
Chris@0:    *
Chris@0:    * @var string
Chris@0:    */
Chris@0:   protected $fileCacheKeySuffix;
Chris@0: 
Chris@0:   /**
Chris@0:    * The key contained in the discovered data that identifies it.
Chris@0:    *
Chris@0:    * @var string
Chris@0:    */
Chris@0:   protected $idKey;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a YamlDirectoryDiscovery object.
Chris@0:    *
Chris@0:    * @param array $directories
Chris@0:    *   An array of directories to scan, keyed by the provider. The value can
Chris@0:    *   either be a string or an array of strings. The string values should be
Chris@0:    *   the path of a directory to scan.
Chris@0:    * @param string $file_cache_key_suffix
Chris@0:    *   The file cache key suffix. This should be unique for each type of
Chris@0:    *   discovery.
Chris@0:    * @param string $key
Chris@0:    *   (optional) The key contained in the discovered data that identifies it.
Chris@0:    *   Defaults to 'id'.
Chris@0:    */
Chris@0:   public function __construct(array $directories, $file_cache_key_suffix, $key = 'id') {
Chris@0:     $this->directories = $directories;
Chris@0:     $this->fileCacheKeySuffix = $file_cache_key_suffix;
Chris@0:     $this->idKey = $key;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function findAll() {
Chris@0:     $all = [];
Chris@0: 
Chris@0:     $files = $this->findFiles();
Chris@0: 
Chris@0:     $file_cache = FileCacheFactory::get('yaml_discovery:' . $this->fileCacheKeySuffix);
Chris@0: 
Chris@0:     // Try to load from the file cache first.
Chris@0:     foreach ($file_cache->getMultiple(array_keys($files)) as $file => $data) {
Chris@0:       $all[$files[$file]][$this->getIdentifier($file, $data)] = $data;
Chris@0:       unset($files[$file]);
Chris@0:     }
Chris@0: 
Chris@0:     // If there are files left that were not returned from the cache, load and
Chris@0:     // parse them now. This list was flipped above and is keyed by filename.
Chris@0:     if ($files) {
Chris@0:       foreach ($files as $file => $provider) {
Chris@0:         // If a file is empty or its contents are commented out, return an empty
Chris@0:         // array instead of NULL for type consistency.
Chris@0:         try {
Chris@0:           $data = Yaml::decode(file_get_contents($file)) ?: [];
Chris@0:         }
Chris@0:         catch (InvalidDataTypeException $e) {
Chris@0:           throw new DiscoveryException("The $file contains invalid YAML", 0, $e);
Chris@0:         }
Chris@0:         $data[static::FILE_KEY] = $file;
Chris@0:         $all[$provider][$this->getIdentifier($file, $data)] = $data;
Chris@0:         $file_cache->set($file, $data);
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     return $all;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Gets the identifier from the data.
Chris@0:    *
Chris@0:    * @param string $file
Chris@0:    *   The filename.
Chris@0:    * @param array $data
Chris@0:    *   The data from the YAML file.
Chris@0:    *
Chris@0:    * @return string
Chris@0:    *   The identifier from the data.
Chris@0:    */
Chris@0:   protected function getIdentifier($file, array $data) {
Chris@0:     if (!isset($data[$this->idKey])) {
Chris@0:       throw new DiscoveryException("The $file contains no data in the identifier key '{$this->idKey}'");
Chris@0:     }
Chris@0:     return $data[$this->idKey];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Returns an array of providers keyed by file path.
Chris@0:    *
Chris@0:    * @return array
Chris@0:    *   An array of providers keyed by file path.
Chris@0:    */
Chris@0:   protected function findFiles() {
Chris@0:     $file_list = [];
Chris@0:     foreach ($this->directories as $provider => $directories) {
Chris@0:       $directories = (array) $directories;
Chris@0:       foreach ($directories as $directory) {
Chris@0:         if (is_dir($directory)) {
Chris@0:           /** @var \SplFileInfo $fileInfo */
Chris@0:           foreach ($this->getDirectoryIterator($directory) as $fileInfo) {
Chris@0:             $file_list[$fileInfo->getPathname()] = $provider;
Chris@0:           }
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0:     return $file_list;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Gets an iterator to loop over the files in the provided directory.
Chris@0:    *
Chris@0:    * This method exists so that it is easy to replace this functionality in a
Chris@0:    * class that extends this one. For example, it could be used to make the scan
Chris@0:    * recursive.
Chris@0:    *
Chris@0:    * @param string $directory
Chris@0:    *   The directory to scan.
Chris@0:    *
Chris@0:    * @return \Traversable
Chris@0:    *   An \Traversable object or array where the values are \SplFileInfo
Chris@0:    *   objects.
Chris@0:    */
Chris@0:   protected function getDirectoryIterator($directory) {
Chris@0:     return new RegexDirectoryIterator($directory, '/\.yml$/i');
Chris@0:   }
Chris@0: 
Chris@0: }