<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Loader

 * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Loader.php 24593 2012-01-05 20:35:02Z matthew $

 */

/**

 * Static methods for loading classes and files.

 *

 * @category   Zend

 * @package    Zend_Loader

 * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Loader

{

    /**

     * Loads a class from a PHP file.  The filename must be formatted

     * as "$class.php".

     *

     * If $dirs is a string or an array, it will search the directories

     * in the order supplied, and attempt to load the first matching file.

     *

     * If $dirs is null, it will split the class name at underscores to

     * generate a path hierarchy (e.g., "Zend_Example_Class" will map

     * to "Zend/Example/Class.php").

     *

     * If the file was not found in the $dirs, or if no $dirs were specified,

     * it will attempt to load it from PHP's include_path.

     *

     * @param string $class      - The full class name of a Zend component.

     * @param string|array $dirs - OPTIONAL Either a path or an array of paths

     *                             to search.

     * @return void

     * @throws Zend_Exception

     */

    public static function loadClass($class, $dirs = null)

    {

        if (class_exists($class, false) || interface_exists($class, false)) {

            return;

        }

        if ((null !== $dirs) && !is_string($dirs) && !is_array($dirs)) {

            require_once 'Zend/Exception.php';

            throw new Zend_Exception('Directory argument must be a string or an array');

        }

        $file = self::standardiseFile($class);

        if (!empty($dirs)) {

            // use the autodiscovered path

            $dirPath = dirname($file);

            if (is_string($dirs)) {

                $dirs = explode(PATH_SEPARATOR, $dirs);

            }

            foreach ($dirs as $key => $dir) {

                if ($dir == '.') {

                    $dirs[$key] = $dirPath;

                } else {

                    $dir = rtrim($dir, '\\/');

                    $dirs[$key] = $dir . DIRECTORY_SEPARATOR . $dirPath;

                }

            }

            $file = basename($file);

            self::loadFile($file, $dirs, true);

        } else {

            self::loadFile($file, null, true);

        }

        if (!class_exists($class, false) && !interface_exists($class, false)) {

            require_once 'Zend/Exception.php';

            throw new Zend_Exception("File \"$file\" does not exist or class \"$class\" was not found in the file");

        }

    }

    /**

     * Loads a PHP file.  This is a wrapper for PHP's include() function.

     *

     * $filename must be the complete filename, including any

     * extension such as ".php".  Note that a security check is performed that

     * does not permit extended characters in the filename.  This method is

     * intended for loading Zend Framework files.

     *

     * If $dirs is a string or an array, it will search the directories

     * in the order supplied, and attempt to load the first matching file.

     *

     * If the file was not found in the $dirs, or if no $dirs were specified,

     * it will attempt to load it from PHP's include_path.

     *

     * If $once is TRUE, it will use include_once() instead of include().

     *

     * @param  string        $filename

     * @param  string|array  $dirs - OPTIONAL either a path or array of paths

     *                       to search.

     * @param  boolean       $once

     * @return boolean

     * @throws Zend_Exception

     */

    public static function loadFile($filename, $dirs = null, $once = false)

    {

        self::_securityCheck($filename);

        /**

         * Search in provided directories, as well as include_path

         */

        $incPath = false;

        if (!empty($dirs) && (is_array($dirs) || is_string($dirs))) {

            if (is_array($dirs)) {

                $dirs = implode(PATH_SEPARATOR, $dirs);

            }

            $incPath = get_include_path();

            set_include_path($dirs . PATH_SEPARATOR . $incPath);

        }

        /**

         * Try finding for the plain filename in the include_path.

         */

        if ($once) {

            include_once $filename;

        } else {

            include $filename;

        }

        /**

         * If searching in directories, reset include_path

         */

        if ($incPath) {

            set_include_path($incPath);

        }

        return true;

    }

    /**

     * Returns TRUE if the $filename is readable, or FALSE otherwise.

     * This function uses the PHP include_path, where PHP's is_readable()

     * does not.

     *

     * Note from ZF-2900:

     * If you use custom error handler, please check whether return value

     *  from error_reporting() is zero or not.

     * At mark of fopen() can not suppress warning if the handler is used.

     *

     * @param string   $filename

     * @return boolean

     */

    public static function isReadable($filename)

    {

        if (is_readable($filename)) {

            // Return early if the filename is readable without needing the

            // include_path

            return true;

        }

        if (strtoupper(substr(PHP_OS, 0, 3)) == 'WIN'

            && preg_match('/^[a-z]:/i', $filename)

        ) {

            // If on windows, and path provided is clearly an absolute path,

            // return false immediately

            return false;

        }

        foreach (self::explodeIncludePath() as $path) {

            if ($path == '.') {

                if (is_readable($filename)) {

                    return true;

                }

                continue;

            }

            $file = $path . '/' . $filename;

            if (is_readable($file)) {

                return true;

            }

        }

        return false;

    }

    /**

     * Explode an include path into an array

     *

     * If no path provided, uses current include_path. Works around issues that

     * occur when the path includes stream schemas.

     *

     * @param  string|null $path

     * @return array

     */

    public static function explodeIncludePath($path = null)

    {

        if (null === $path) {

            $path = get_include_path();

        }

        if (PATH_SEPARATOR == ':') {

            // On *nix systems, include_paths which include paths with a stream

            // schema cannot be safely explode'd, so we have to be a bit more

            // intelligent in the approach.

            $paths = preg_split('#:(?!//)#', $path);

        } else {

            $paths = explode(PATH_SEPARATOR, $path);

        }

        return $paths;

    }

    /**

     * spl_autoload() suitable implementation for supporting class autoloading.

     *

     * Attach to spl_autoload() using the following:

     * <code>

     * spl_autoload_register(array('Zend_Loader', 'autoload'));

     * </code>

     *

     * @deprecated Since 1.8.0

     * @param  string $class

     * @return string|false Class name on success; false on failure

     */

    public static function autoload($class)

    {

        trigger_error(__CLASS__ . '::' . __METHOD__ . ' is deprecated as of 1.8.0 and will be removed with 2.0.0; use Zend_Loader_Autoloader instead', E_USER_NOTICE);

        try {

            @self::loadClass($class);

            return $class;

        } catch (Exception $e) {

            return false;

        }

    }

    /**

     * Register {@link autoload()} with spl_autoload()

     *

     * @deprecated Since 1.8.0

     * @param string $class (optional)

     * @param boolean $enabled (optional)

     * @return void

     * @throws Zend_Exception if spl_autoload() is not found

     * or if the specified class does not have an autoload() method.

     */

    public static function registerAutoload($class = 'Zend_Loader', $enabled = true)

    {

        trigger_error(__CLASS__ . '::' . __METHOD__ . ' is deprecated as of 1.8.0 and will be removed with 2.0.0; use Zend_Loader_Autoloader instead', E_USER_NOTICE);

        require_once 'Zend/Loader/Autoloader.php';

        $autoloader = Zend_Loader_Autoloader::getInstance();

        $autoloader->setFallbackAutoloader(true);

        if ('Zend_Loader' != $class) {

            self::loadClass($class);

            $methods = get_class_methods($class);

            if (!in_array('autoload', (array) $methods)) {

                require_once 'Zend/Exception.php';

                throw new Zend_Exception("The class \"$class\" does not have an autoload() method");

            }

            $callback = array($class, 'autoload');

            if ($enabled) {

                $autoloader->pushAutoloader($callback);

            } else {

                $autoloader->removeAutoloader($callback);

            }

        }

    }

    /**

     * Ensure that filename does not contain exploits

     *

     * @param  string $filename

     * @return void

     * @throws Zend_Exception

     */

    protected static function _securityCheck($filename)

    {

        /**

         * Security check

         */

        if (preg_match('/[^a-z0-9\\/\\\\_.:-]/i', $filename)) {

            require_once 'Zend/Exception.php';

            throw new Zend_Exception('Security check: Illegal character in filename');

        }

    }

    /**

     * Attempt to include() the file.

     *

     * include() is not prefixed with the @ operator because if

     * the file is loaded and contains a parse error, execution

     * will halt silently and this is difficult to debug.

     *

     * Always set display_errors = Off on production servers!

     *

     * @param  string  $filespec

     * @param  boolean $once

     * @return boolean

     * @deprecated Since 1.5.0; use loadFile() instead

     */

    protected static function _includeFile($filespec, $once = false)

    {

        if ($once) {

            return include_once $filespec;

        } else {

            return include $filespec ;

        }

    }

    /**

     * Standardise the filename.

     *

     * Convert the supplied filename into the namespace-aware standard,

     * based on the Framework Interop Group reference implementation:

     * http://groups.google.com/group/php-standards/web/psr-0-final-proposal

     *

     * The filename must be formatted as "$file.php".

     *

     * @param string $file - The file name to be loaded.

     * @return string

     */

    public static function standardiseFile($file)

    {

        $fileName = ltrim($file, '\\');

        $file      = '';

        $namespace = '';

        if ($lastNsPos = strripos($fileName, '\\')) {

            $namespace = substr($fileName, 0, $lastNsPos);

            $fileName = substr($fileName, $lastNsPos + 1);

            $file      = str_replace('\\', DIRECTORY_SEPARATOR, $namespace) . DIRECTORY_SEPARATOR;

        }

        $file .= str_replace('_', DIRECTORY_SEPARATOR, $fileName) . '.php';

        return $file;    

    }

}