File Source for loader.php

<?php
/**
* @package Joomla.Platform
*
* @copyright Copyright (C) 2005 - 2013 Open Source Matters, Inc. All rights reserved.
* @license GNU General Public License version 2 or later; see LICENSE
*/
defined('JPATH_PLATFORM') or die;
/**
* Static class to handle loading of libraries.
*
* @package Joomla.Platform
* @since 11.1
*/
abstract class JLoader
{
/**
* Container for already imported library paths.
*
* @var array
* @since 11.1
*/
protected static $classes = array();
/**
* Container for already imported library paths.
*
* @var array
* @since 11.1
*/
protected static $imported = array();
/**
* Container for registered library class prefixes and path lookups.
*
* @var array
* @since 12.1
*/
protected static $prefixes = array();
/**
* Holds proxy classes and the class names the proxy.
*
* @var array
* @since 3.2
*/
protected static $classAliases = array();
/**
* Container for namespace => path map.
*
* @var array
* @since 12.3
*/
protected static $namespaces = array();
/**
* Method to discover classes of a given type in a given path.
*
* @param string $classPrefix The class name prefix to use for discovery.
* @param string $parentPath Full path to the parent folder for the classes to discover.
* @param boolean $force True to overwrite the autoload path value for the class if it already exists.
* @param boolean $recurse Recurse through all child directories as well as the parent path.
*
* @return void
*
* @since 11.1
*/
public static function discover($classPrefix, $parentPath, $force = true, $recurse = false)
{
try
{
if ($recurse)
{
$iterator = new RecursiveIteratorIterator(
new RecursiveDirectoryIterator($parentPath),
RecursiveIteratorIterator::SELF_FIRST
);
}
else
{
$iterator = new DirectoryIterator($parentPath);
}
foreach ($iterator as $file)
{
$fileName = $file->getFilename();
// Only load for php files.
// Note: DirectoryIterator::getExtension only available PHP >= 5.3.6
if ($file->isFile() && substr($fileName, strrpos($fileName, '.') + 1) == 'php')
{
// Get the class name and full path for each file.
$class = strtolower($classPrefix . preg_replace('#\.php$#', '', $fileName));
// Register the class with the autoloader if not already registered or the force flag is set.
if (empty(self::$classes[$class]) || $force)
{
self::register($class, $file->getPath() . '/' . $fileName);
}
}
}
}
catch (UnexpectedValueException $e)
{
// Exception will be thrown if the path is not a directory. Ignore it.
}
}
/**
* Method to get the list of registered classes and their respective file paths for the autoloader.
*
* @return array The array of class => path values for the autoloader.
*
* @since 11.1
*/
public static function getClassList()
{
return self::$classes;
}
/**
* Method to get the list of registered namespaces.
*
* @return array The array of namespace => path values for the autoloader.
*
* @since 12.3
*/
public static function getNamespaces()
{
return self::$namespaces;
}
/**
* Loads a class from specified directories.
*
* @param string $key The class name to look for (dot notation).
* @param string $base Search this directory for the class.
*
* @return boolean True on success.
*
* @since 11.1
*/
public static function import($key, $base = null)
{
// Only import the library if not already attempted.
if (!isset(self::$imported[$key]))
{
// Setup some variables.
$success = false;
$parts = explode('.', $key);
$class = array_pop($parts);
$base = (!empty($base)) ? $base : __DIR__;
$path = str_replace('.', DIRECTORY_SEPARATOR, $key);
// Handle special case for helper classes.
if ($class == 'helper')
{
$class = ucfirst(array_pop($parts)) . ucfirst($class);
}
// Standard class.
else
{
$class = ucfirst($class);
}
// If we are importing a library from the Joomla namespace set the class to autoload.
if (strpos($path, 'joomla') === 0)
{
// Since we are in the Joomla namespace prepend the classname with J.
$class = 'J' . $class;
// Only register the class for autoloading if the file exists.
if (is_file($base . '/' . $path . '.php'))
{
self::$classes[strtolower($class)] = $base . '/' . $path . '.php';
$success = true;
}
}
/*
* If we are not importing a library from the Joomla namespace directly include the
* file since we cannot assert the file/folder naming conventions.
*/
else
{
// If the file exists attempt to include it.
if (is_file($base . '/' . $path . '.php'))
{
$success = (bool) include_once $base . '/' . $path . '.php';
}
}
// Add the import key to the memory cache container.
self::$imported[$key] = $success;
}
return self::$imported[$key];
}
/**
* Load the file for a class.
*
* @param string $class The class to be loaded.
*
* @return boolean True on success
*
* @since 11.1
*/
public static function load($class)
{
// Sanitize class name.
$class = strtolower($class);
// If the class already exists do nothing.
if (class_exists($class, false))
{
return true;
}
// If the class is registered include the file.
if (isset(self::$classes[$class]))
{
include_once self::$classes[$class];
return true;
}
return false;
}
/**
* Directly register a class to the autoload list.
*
* @param string $class The class name to register.
* @param string $path Full path to the file that holds the class to register.
* @param boolean $force True to overwrite the autoload path value for the class if it already exists.
*
* @return void
*
* @since 11.1
*/
public static function register($class, $path, $force = true)
{
// Sanitize class name.
$class = strtolower($class);
// Only attempt to register the class if the name and file exist.
if (!empty($class) && is_file($path))
{
// Register the class with the autoloader if not already registered or the force flag is set.
if (empty(self::$classes[$class]) || $force)
{
self::$classes[$class] = $path;
}
}
}
/**
* Register a class prefix with lookup path. This will allow developers to register library
* packages with different class prefixes to the system autoloader. More than one lookup path
* may be registered for the same class prefix, but if this method is called with the reset flag
* set to true then any registered lookups for the given prefix will be overwritten with the current
* lookup path. When loaded, prefix paths are searched in a "last in, first out" order.
*
* @param string $prefix The class prefix to register.
* @param string $path Absolute file path to the library root where classes with the given prefix can be found.
* @param boolean $reset True to reset the prefix with only the given lookup path.
* @param boolean $prepend If true, push the path to the beginning of the prefix lookup paths array.
*
* @return void
*
* @throws RuntimeException
*
* @since 12.1
*/
public static function registerPrefix($prefix, $path, $reset = false, $prepend = false)
{
// Verify the library path exists.
if (!file_exists($path))
{
throw new RuntimeException('Library path ' . $path . ' cannot be found.', 500);
}
// If the prefix is not yet registered or we have an explicit reset flag then set set the path.
if (!isset(self::$prefixes[$prefix]) || $reset)
{
self::$prefixes[$prefix] = array($path);
}
// Otherwise we want to simply add the path to the prefix.
else
{
if ($prepend)
{
array_unshift(self::$prefixes[$prefix], $path);
}
else
{
self::$prefixes[$prefix][] = $path;
}
}
}
/**
* Offers the ability for "just in time" usage of `class_alias()`.
* You cannot overwrite an existing alias.
*
* @param string $alias The alias name to register.
* @param string $original The original class to alias.
*
* @return boolean True if registration was successful. False if the alias already exists.
*
* @since 3.2
*/
public static function registerAlias($alias, $original)
{
if (!isset(self::$classAliases[$alias]))
{
self::$classAliases[$alias] = $original;
return true;
}
return false;
}
/**
* Register a namespace to the autoloader. When loaded, namespace paths are searched in a "last in, first out" order.
*
* @param string $namespace A case sensitive Namespace to register.
* @param string $path A case sensitive absolute file path to the library root where classes of the given namespace can be found.
* @param boolean $reset True to reset the namespace with only the given lookup path.
* @param boolean $prepend If true, push the path to the beginning of the namespace lookup paths array.
*
* @return void
*
* @throws RuntimeException
*
* @since 12.3
*/
public static function registerNamespace($namespace, $path, $reset = false, $prepend = false)
{
// Verify the library path exists.
if (!file_exists($path))
{
throw new RuntimeException('Library path ' . $path . ' cannot be found.', 500);
}
// If the namespace is not yet registered or we have an explicit reset flag then set the path.
if (!isset(self::$namespaces[$namespace]) || $reset)
{
self::$namespaces[$namespace] = array($path);
}
// Otherwise we want to simply add the path to the namespace.
else
{
if ($prepend)
{
array_unshift(self::$namespaces[$namespace], $path);
}
else
{
self::$namespaces[$namespace][] = $path;
}
}
}
/**
* Method to setup the autoloaders for the Joomla Platform.
* Since the SPL autoloaders are called in a queue we will add our explicit
* class-registration based loader first, then fall back on the autoloader based on conventions.
* This will allow people to register a class in a specific location and override platform libraries
* as was previously possible.
*
* @param boolean $enablePsr True to enable autoloading based on PSR-0.
* @param boolean $enablePrefixes True to enable prefix based class loading (needed to auto load the Joomla core).
* @param boolean $enableClasses True to enable class map based class loading (needed to auto load the Joomla core).
*
* @return void
*
* @since 12.3
*/
public static function setup($enablePsr = true, $enablePrefixes = true, $enableClasses = true)
{
if ($enableClasses)
{
// Register the class map based autoloader.
spl_autoload_register(array('JLoader', 'load'));
}
if ($enablePrefixes)
{
// Register the J prefix and base path for Joomla platform libraries.
self::registerPrefix('J', JPATH_PLATFORM . '/joomla');
// Register the prefix autoloader.
spl_autoload_register(array('JLoader', '_autoload'));
}
if ($enablePsr)
{
// Register the PSR-0 based autoloader.
spl_autoload_register(array('JLoader', 'loadByPsr0'));
spl_autoload_register(array('JLoader', 'loadByAlias'));
}
}
/**
* Method to autoload classes that are namespaced to the PSR-0 standard.
*
* @param string $class The fully qualified class name to autoload.
*
* @return boolean True on success, false otherwise.
*
* @since 13.1
*/
public static function loadByPsr0($class)
{
// Remove the root backslash if present.
if ($class[0] == '\\')
{
$class = substr($class, 1);
}
// Find the location of the last NS separator.
$pos = strrpos($class, '\\');
// If one is found, we're dealing with a NS'd class.
if ($pos !== false)
{
$classPath = str_replace('\\', DIRECTORY_SEPARATOR, substr($class, 0, $pos)) . DIRECTORY_SEPARATOR;
$className = substr($class, $pos + 1);
}
// If not, no need to parse path.
else
{
$classPath = null;
$className = $class;
}
$classPath .= str_replace('_', DIRECTORY_SEPARATOR, $className) . '.php';
// Loop through registered namespaces until we find a match.
foreach (self::$namespaces as $ns => $paths)
{
if (strpos($class, $ns) === 0)
{
// Loop through paths registered to this namespace until we find a match.
foreach ($paths as $path)
{
$classFilePath = $path . DIRECTORY_SEPARATOR . $classPath;
// We check for class_exists to handle case-sensitive file systems
if (file_exists($classFilePath) && !class_exists($class, false))
{
return (bool) include_once $classFilePath;
}
}
}
}
return false;
}
/**
* Method to autoload classes that have been aliased using the registerAlias method.
*
* @param string $class The fully qualified class name to autoload.
*
* @return boolean True on success, false otherwise.
*
* @since 3.2
*/
public static function loadByAlias($class)
{
// Remove the root backslash if present.
if ($class[0] == '\\')
{
$class = substr($class, 1);
}
if (isset(self::$classAliases[$class]))
{
class_alias(self::$classAliases[$class], $class);
}
}
/**
* Autoload a class based on name.
*
* @param string $class The class to be loaded.
*
* @return boolean True if the class was loaded, false otherwise.
*
* @since 11.3
*/
private static function _autoload($class)
{
foreach (self::$prefixes as $prefix => $lookup)
{
$chr = strlen($prefix) < strlen($class) ? $class[strlen($prefix)] : 0;
if (strpos($class, $prefix) === 0 && ($chr === strtoupper($chr)))
{
return self::_load(substr($class, strlen($prefix)), $lookup);
}
}
return false;
}
/**
* Load a class based on name and lookup array.
*
* @param string $class The class to be loaded (wihtout prefix).
* @param array $lookup The array of base paths to use for finding the class file.
*
* @return boolean True if the class was loaded, false otherwise.
*
* @since 12.1
*/
private static function _load($class, $lookup)
{
// Split the class name into parts separated by camelCase.
$parts = preg_split('/(?<=[a-z0-9])(?=[A-Z])/x', $class);
// If there is only one part we want to duplicate that part for generating the path.
$parts = (count($parts) === 1) ? array($parts[0], $parts[0]) : $parts;
foreach ($lookup as $base)
{
// Generate the path based on the class name parts.
$path = $base . '/' . implode('/', array_map('strtolower', $parts)) . '.php';
// Load the file if it exists.
if (file_exists($path))
{
return include $path;
}
}
return false;
}
}
/**
* Global application exit.
*
* This function provides a single exit point for the platform.
*
* @param mixed $message Exit code or string. Defaults to zero.
*
* @return void
*
* @codeCoverageIgnore
* @since 11.1
*/
function jexit($message = 0)
{
exit($message);
}
/**
* Intelligent file importer.
*
* @param string $path A dot syntax path.
*
* @return boolean True on success.
*
* @since 11.1
*/
function jimport($path)
{
return JLoader::import($path);
}

Documentation generated on Tue, 19 Nov 2013 15:07:23 +0100 by phpDocumentor 1.4.3

Source for file loader.php