1: <?php
  2: 
  3: /*
  4:  * This file is part of the Symfony package.
  5:  *
  6:  * (c) Fabien Potencier <fabien@symfony.com>
  7:  *
  8:  * For the full copyright and license information, please view the LICENSE
  9:  * file that was distributed with this source code.
 10:  */
 11: 
 12: namespace Symfony\Component\HttpFoundation\File\MimeType;
 13: 
 14: use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
 15: use Symfony\Component\HttpFoundation\File\Exception\AccessDeniedException;
 16: 
 17: /**
 18:  * A singleton mime type guesser.
 19:  *
 20:  * By default, all mime type guessers provided by the framework are installed
 21:  * (if available on the current OS/PHP setup). You can register custom
 22:  * guessers by calling the register() method on the singleton instance.
 23:  *
 24:  * <code>
 25:  * $guesser = MimeTypeGuesser::getInstance();
 26:  * $guesser->register(new MyCustomMimeTypeGuesser());
 27:  * </code>
 28:  *
 29:  * The last registered guesser is preferred over previously registered ones.
 30:  *
 31:  * @author Bernhard Schussek <bschussek@gmail.com>
 32:  */
 33: class MimeTypeGuesser implements MimeTypeGuesserInterface
 34: {
 35:     /**
 36:      * The singleton instance
 37:      *
 38:      * @var MimeTypeGuesser
 39:      */
 40:     private static $instance = null;
 41: 
 42:     /**
 43:      * All registered MimeTypeGuesserInterface instances
 44:      *
 45:      * @var array
 46:      */
 47:     protected $guessers = array();
 48: 
 49:     /**
 50:      * Returns the singleton instance
 51:      *
 52:      * @return MimeTypeGuesser
 53:      */
 54:     public static function getInstance()
 55:     {
 56:         if (null === self::$instance) {
 57:             self::$instance = new self();
 58:         }
 59: 
 60:         return self::$instance;
 61:     }
 62: 
 63:     /**
 64:      * Registers all natively provided mime type guessers
 65:      */
 66:     private function __construct()
 67:     {
 68:         if (FileBinaryMimeTypeGuesser::isSupported()) {
 69:             $this->register(new FileBinaryMimeTypeGuesser());
 70:         }
 71: 
 72:         if (FileinfoMimeTypeGuesser::isSupported()) {
 73:             $this->register(new FileinfoMimeTypeGuesser());
 74:         }
 75:     }
 76: 
 77:     /**
 78:      * Registers a new mime type guesser
 79:      *
 80:      * When guessing, this guesser is preferred over previously registered ones.
 81:      *
 82:      * @param MimeTypeGuesserInterface $guesser
 83:      */
 84:     public function register(MimeTypeGuesserInterface $guesser)
 85:     {
 86:         array_unshift($this->guessers, $guesser);
 87:     }
 88: 
 89:     /**
 90:      * Tries to guess the mime type of the given file
 91:      *
 92:      * The file is passed to each registered mime type guesser in reverse order
 93:      * of their registration (last registered is queried first). Once a guesser
 94:      * returns a value that is not NULL, this method terminates and returns the
 95:      * value.
 96:      *
 97:      * @param string $path The path to the file
 98:      *
 99:      * @return string         The mime type or NULL, if none could be guessed
100:      *
101:      * @throws \LogicException
102:      * @throws FileNotFoundException
103:      * @throws AccessDeniedException
104:      */
105:     public function guess($path)
106:     {
107:         if (!is_file($path)) {
108:             throw new FileNotFoundException($path);
109:         }
110: 
111:         if (!is_readable($path)) {
112:             throw new AccessDeniedException($path);
113:         }
114: 
115:         if (!$this->guessers) {
116:             throw new \LogicException('Unable to guess the mime type as no guessers are available (Did you enable the php_fileinfo extension?)');
117:         }
118: 
119:         foreach ($this->guessers as $guesser) {
120:             if (null !== $mimeType = $guesser->guess($path)) {
121:                 return $mimeType;
122:             }
123:         }
124:     }
125: }
126: