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class ClassLoader in Express 8

ClassLoader implements a PSR-0, PSR-4 and classmap class loader.

$loader = new \Composer\Autoload\ClassLoader();

// register classes with namespaces $loader->add('Symfony\Component', __DIR__.'/component'); $loader->add('Symfony', __DIR__.'/framework');

// activate the autoloader $loader->register();

// to enable searching the include path (eg. for PEAR packages) $loader->setUseIncludePath(true);

In this example, if you try to use a class in the Symfony\Component namespace or one of its children (Symfony\Component\Console for instance), the autoloader will first look for the class under the component/ directory, and it will then fallback to the framework/ directory if not found before giving up.

This class is loosely based on the Symfony UniversalClassLoader.

@author Fabien Potencier <fabien@symfony.com> @author Jordi Boggiano <j.boggiano@seld.be>

Hierarchy

Expanded class hierarchy of ClassLoader

See also

http://www.php-fig.org/psr/psr-0/

http://www.php-fig.org/psr/psr-4/

File

vendor/composer/ClassLoader.php, line 43

Namespace

Composer\Autoload
View source 
class ClassLoader {

  // PSR-4
  private $prefixLengthsPsr4 = array();
  private $prefixDirsPsr4 = array();
  private $fallbackDirsPsr4 = array();

  // PSR-0
  private $prefixesPsr0 = array();
  private $fallbackDirsPsr0 = array();
  private $useIncludePath = false;
  private $classMap = array();
  private $classMapAuthoritative = false;
  private $missingClasses = array();
  public function getPrefixes() {
    if (!empty($this->prefixesPsr0)) {
      return call_user_func_array('array_merge', $this->prefixesPsr0);
    }
    return array();
  }
  public function getPrefixesPsr4() {
    return $this->prefixDirsPsr4;
  }
  public function getFallbackDirs() {
    return $this->fallbackDirsPsr0;
  }
  public function getFallbackDirsPsr4() {
    return $this->fallbackDirsPsr4;
  }
  public function getClassMap() {
    return $this->classMap;
  }

  /**
   * @param array $classMap Class to filename map
   */
  public function addClassMap(array $classMap) {
    if ($this->classMap) {
      $this->classMap = array_merge($this->classMap, $classMap);
    }
    else {
      $this->classMap = $classMap;
    }
  }

  /**
   * Registers a set of PSR-0 directories for a given prefix, either
   * appending or prepending to the ones previously set for this prefix.
   *
   * @param string       $prefix  The prefix
   * @param array|string $paths   The PSR-0 root directories
   * @param bool         $prepend Whether to prepend the directories
   */
  public function add($prefix, $paths, $prepend = false) {
    if (!$prefix) {
      if ($prepend) {
        $this->fallbackDirsPsr0 = array_merge((array) $paths, $this->fallbackDirsPsr0);
      }
      else {
        $this->fallbackDirsPsr0 = array_merge($this->fallbackDirsPsr0, (array) $paths);
      }
      return;
    }
    $first = $prefix[0];
    if (!isset($this->prefixesPsr0[$first][$prefix])) {
      $this->prefixesPsr0[$first][$prefix] = (array) $paths;
      return;
    }
    if ($prepend) {
      $this->prefixesPsr0[$first][$prefix] = array_merge((array) $paths, $this->prefixesPsr0[$first][$prefix]);
    }
    else {
      $this->prefixesPsr0[$first][$prefix] = array_merge($this->prefixesPsr0[$first][$prefix], (array) $paths);
    }
  }

  /**
   * Registers a set of PSR-4 directories for a given namespace, either
   * appending or prepending to the ones previously set for this namespace.
   *
   * @param string       $prefix  The prefix/namespace, with trailing '\\'
   * @param array|string $paths   The PSR-4 base directories
   * @param bool         $prepend Whether to prepend the directories
   *
   * @throws \InvalidArgumentException
   */
  public function addPsr4($prefix, $paths, $prepend = false) {
    if (!$prefix) {

      // Register directories for the root namespace.
      if ($prepend) {
        $this->fallbackDirsPsr4 = array_merge((array) $paths, $this->fallbackDirsPsr4);
      }
      else {
        $this->fallbackDirsPsr4 = array_merge($this->fallbackDirsPsr4, (array) $paths);
      }
    }
    elseif (!isset($this->prefixDirsPsr4[$prefix])) {

      // Register directories for a new namespace.
      $length = strlen($prefix);
      if ('\\' !== $prefix[$length - 1]) {
        throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
      }
      $this->prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
      $this->prefixDirsPsr4[$prefix] = (array) $paths;
    }
    elseif ($prepend) {

      // Prepend directories for an already registered namespace.
      $this->prefixDirsPsr4[$prefix] = array_merge((array) $paths, $this->prefixDirsPsr4[$prefix]);
    }
    else {

      // Append directories for an already registered namespace.
      $this->prefixDirsPsr4[$prefix] = array_merge($this->prefixDirsPsr4[$prefix], (array) $paths);
    }
  }

  /**
   * Registers a set of PSR-0 directories for a given prefix,
   * replacing any others previously set for this prefix.
   *
   * @param string       $prefix The prefix
   * @param array|string $paths  The PSR-0 base directories
   */
  public function set($prefix, $paths) {
    if (!$prefix) {
      $this->fallbackDirsPsr0 = (array) $paths;
    }
    else {
      $this->prefixesPsr0[$prefix[0]][$prefix] = (array) $paths;
    }
  }

  /**
   * Registers a set of PSR-4 directories for a given namespace,
   * replacing any others previously set for this namespace.
   *
   * @param string       $prefix The prefix/namespace, with trailing '\\'
   * @param array|string $paths  The PSR-4 base directories
   *
   * @throws \InvalidArgumentException
   */
  public function setPsr4($prefix, $paths) {
    if (!$prefix) {
      $this->fallbackDirsPsr4 = (array) $paths;
    }
    else {
      $length = strlen($prefix);
      if ('\\' !== $prefix[$length - 1]) {
        throw new \InvalidArgumentException("A non-empty PSR-4 prefix must end with a namespace separator.");
      }
      $this->prefixLengthsPsr4[$prefix[0]][$prefix] = $length;
      $this->prefixDirsPsr4[$prefix] = (array) $paths;
    }
  }

  /**
   * Turns on searching the include path for class files.
   *
   * @param bool $useIncludePath
   */
  public function setUseIncludePath($useIncludePath) {
    $this->useIncludePath = $useIncludePath;
  }

  /**
   * Can be used to check if the autoloader uses the include path to check
   * for classes.
   *
   * @return bool
   */
  public function getUseIncludePath() {
    return $this->useIncludePath;
  }

  /**
   * Turns off searching the prefix and fallback directories for classes
   * that have not been registered with the class map.
   *
   * @param bool $classMapAuthoritative
   */
  public function setClassMapAuthoritative($classMapAuthoritative) {
    $this->classMapAuthoritative = $classMapAuthoritative;
  }

  /**
   * Should class lookup fail if not found in the current class map?
   *
   * @return bool
   */
  public function isClassMapAuthoritative() {
    return $this->classMapAuthoritative;
  }

  /**
   * Registers this instance as an autoloader.
   *
   * @param bool $prepend Whether to prepend the autoloader or not
   */
  public function register($prepend = false) {
    spl_autoload_register(array(
      $this,
      'loadClass',
    ), true, $prepend);
  }

  /**
   * Unregisters this instance as an autoloader.
   */
  public function unregister() {
    spl_autoload_unregister(array(
      $this,
      'loadClass',
    ));
  }

  /**
   * Loads the given class or interface.
   *
   * @param  string    $class The name of the class
   * @return bool|null True if loaded, null otherwise
   */
  public function loadClass($class) {
    if ($file = $this
      ->findFile($class)) {
      includeFile($file);
      return true;
    }
  }

  /**
   * Finds the path to the file where the class is defined.
   *
   * @param string $class The name of the class
   *
   * @return string|false The path if found, false otherwise
   */
  public function findFile($class) {

    // work around for PHP 5.3.0 - 5.3.2 https://bugs.php.net/50731
    if ('\\' == $class[0]) {
      $class = substr($class, 1);
    }

    // class map lookup
    if (isset($this->classMap[$class])) {
      return $this->classMap[$class];
    }
    if ($this->classMapAuthoritative || isset($this->missingClasses[$class])) {
      return false;
    }
    $file = $this
      ->findFileWithExtension($class, '.php');

    // Search for Hack files if we are running on HHVM
    if (false === $file && defined('HHVM_VERSION')) {
      $file = $this
        ->findFileWithExtension($class, '.hh');
    }
    if (false === $file) {

      // Remember that this class does not exist.
      $this->missingClasses[$class] = true;
    }
    return $file;
  }
  private function findFileWithExtension($class, $ext) {

    // PSR-4 lookup
    $logicalPathPsr4 = strtr($class, '\\', DIRECTORY_SEPARATOR) . $ext;
    $first = $class[0];
    if (isset($this->prefixLengthsPsr4[$first])) {
      foreach ($this->prefixLengthsPsr4[$first] as $prefix => $length) {
        if (0 === strpos($class, $prefix)) {
          foreach ($this->prefixDirsPsr4[$prefix] as $dir) {
            if (file_exists($file = $dir . DIRECTORY_SEPARATOR . substr($logicalPathPsr4, $length))) {
              return $file;
            }
          }
        }
      }
    }

    // PSR-4 fallback dirs
    foreach ($this->fallbackDirsPsr4 as $dir) {
      if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr4)) {
        return $file;
      }
    }

    // PSR-0 lookup
    if (false !== ($pos = strrpos($class, '\\'))) {

      // namespaced class name
      $logicalPathPsr0 = substr($logicalPathPsr4, 0, $pos + 1) . strtr(substr($logicalPathPsr4, $pos + 1), '_', DIRECTORY_SEPARATOR);
    }
    else {

      // PEAR-like class name
      $logicalPathPsr0 = strtr($class, '_', DIRECTORY_SEPARATOR) . $ext;
    }
    if (isset($this->prefixesPsr0[$first])) {
      foreach ($this->prefixesPsr0[$first] as $prefix => $dirs) {
        if (0 === strpos($class, $prefix)) {
          foreach ($dirs as $dir) {
            if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
              return $file;
            }
          }
        }
      }
    }

    // PSR-0 fallback dirs
    foreach ($this->fallbackDirsPsr0 as $dir) {
      if (file_exists($file = $dir . DIRECTORY_SEPARATOR . $logicalPathPsr0)) {
        return $file;
      }
    }

    // PSR-0 include paths.
    if ($this->useIncludePath && ($file = stream_resolve_include_path($logicalPathPsr0))) {
      return $file;
    }
    return false;
  }

}

Members

Namesort descending Modifiers Type Description Overrides
ClassLoader::$classMap private property
ClassLoader::$classMapAuthoritative private property
ClassLoader::$fallbackDirsPsr0 private property
ClassLoader::$fallbackDirsPsr4 private property
ClassLoader::$missingClasses private property
ClassLoader::$prefixDirsPsr4 private property
ClassLoader::$prefixesPsr0 private property
ClassLoader::$prefixLengthsPsr4 private property
ClassLoader::$useIncludePath private property
ClassLoader::add public function Registers a set of PSR-0 directories for a given prefix, either appending or prepending to the ones previously set for this prefix.
ClassLoader::addClassMap public function
ClassLoader::addPsr4 public function Registers a set of PSR-4 directories for a given namespace, either appending or prepending to the ones previously set for this namespace.
ClassLoader::findFile public function Finds the path to the file where the class is defined.
ClassLoader::findFileWithExtension private function
ClassLoader::getClassMap public function
ClassLoader::getFallbackDirs public function
ClassLoader::getFallbackDirsPsr4 public function
ClassLoader::getPrefixes public function
ClassLoader::getPrefixesPsr4 public function
ClassLoader::getUseIncludePath public function Can be used to check if the autoloader uses the include path to check for classes.
ClassLoader::isClassMapAuthoritative public function Should class lookup fail if not found in the current class map?
ClassLoader::loadClass public function Loads the given class or interface.
ClassLoader::register public function Registers this instance as an autoloader.
ClassLoader::set public function Registers a set of PSR-0 directories for a given prefix, replacing any others previously set for this prefix.
ClassLoader::setClassMapAuthoritative public function Turns off searching the prefix and fallback directories for classes that have not been registered with the class map.
ClassLoader::setPsr4 public function Registers a set of PSR-4 directories for a given namespace, replacing any others previously set for this namespace.
ClassLoader::setUseIncludePath public function Turns on searching the include path for class files.
ClassLoader::unregister public function Unregisters this instance as an autoloader.