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<?php
/*
* This file is part of the Symfony package.
*
* (c) Fabien Potencier <fabien@symfony.com>
*
* For the full copyright and license information, please view the LICENSE
* file that was distributed with this source code.
*/
namespace Symfony\Component\HttpFoundation\File\MimeType;
use Symfony\Component\HttpFoundation\File\Exception\AccessDeniedException;
use Symfony\Component\HttpFoundation\File\Exception\FileNotFoundException;
/**
* A singleton mime type guesser.
*
* By default, all mime type guessers provided by the framework are installed
* (if available on the current OS/PHP setup).
*
* You can register custom guessers by calling the register() method on the
* singleton instance. Custom guessers are always called before any default ones.
*
* $guesser = MimeTypeGuesser::getInstance();
* $guesser->register(new MyCustomMimeTypeGuesser());
*
* If you want to change the order of the default guessers, just re-register your
* preferred one as a custom one. The last registered guesser is preferred over
* previously registered ones.
*
* Re-registering a built-in guesser also allows you to configure it:
*
* $guesser = MimeTypeGuesser::getInstance();
* $guesser->register(new FileinfoMimeTypeGuesser('/path/to/magic/file'));
*
* @author Bernhard Schussek <bschussek@gmail.com>
*/
class MimeTypeGuesser implements MimeTypeGuesserInterface
{
/**
* The singleton instance.
*
* @var MimeTypeGuesser
*/
private static $instance = null;
/**
* All registered MimeTypeGuesserInterface instances.
*
* @var array
*/
protected $guessers = array();
/**
* Returns the singleton instance.
*
* @return self
*/
public static function getInstance()
{
if (null === self::$instance) {
self::$instance = new self();
}
return self::$instance;
}
/**
* Resets the singleton instance.
*/
public static function reset()
{
self::$instance = null;
}
/**
* Registers all natively provided mime type guessers.
*/
private function __construct()
{
$this->register(new FileBinaryMimeTypeGuesser());
$this->register(new FileinfoMimeTypeGuesser());
}
/**
* Registers a new mime type guesser.
*
* When guessing, this guesser is preferred over previously registered ones.
*/
public function register(MimeTypeGuesserInterface $guesser)
{
array_unshift($this->guessers, $guesser);
}
/**
* Tries to guess the mime type of the given file.
*
* The file is passed to each registered mime type guesser in reverse order
* of their registration (last registered is queried first). Once a guesser
* returns a value that is not NULL, this method terminates and returns the
* value.
*
* @param string $path The path to the file
*
* @return string The mime type or NULL, if none could be guessed
*
* @throws \LogicException
* @throws FileNotFoundException
* @throws AccessDeniedException
*/
public function guess($path)
{
if (!is_file($path)) {
throw new FileNotFoundException($path);
}
if (!is_readable($path)) {
throw new AccessDeniedException($path);
}
foreach ($this->guessers as $guesser) {
if (null !== $mimeType = $guesser->guess($path)) {
return $mimeType;
}
}
if (2 === \count($this->guessers) && !FileBinaryMimeTypeGuesser::isSupported() && !FileinfoMimeTypeGuesser::isSupported()) {
throw new \LogicException('Unable to guess the mime type as no guessers are available (Did you enable the php_fileinfo extension?)');
}
}
}