Core Improvements: Next Round #79 #80

libraries/Gelato/ClassLoader/ClassLoader.php

@@ -0,0 +1,205 @@
+<?php
+
+/**
+ * Gelato Library
+ *
+ * This source file is part of the Gelato Library. More information,
+ * documentation and tutorials can be found at http://gelato.monstra.org
+ *
+ * @package     Gelato
+ *
+ * @author      Romanenko Sergey / Awilum
+ * @copyright   (c) 2013 Romanenko Sergey / Awilum
+ * @since       1.0.0
+ */
+
+class ClassLoader
+{
+
+    /**
+     * Mapping from class names to paths.
+     *
+     * @var array
+     */
+    protected static $classes = array();
+
+    /**
+     * PSR-0 directories.
+     *
+     * @var array
+     */
+    protected static $directories = array();
+
+    /**
+     * Registered namespaces.
+     *
+     * @var array
+     */
+    protected static $namespaces = array();
+
+    /**
+     * Class aliases.
+     *
+     * @var array
+     */
+    protected static $aliases = array();
+
+    /**
+     * Protected constructor since this is a static class.
+     *
+     * @access  protected
+     */
+    protected function __construct()
+    {
+        // Nothing here
+    }
+
+    /**
+     * Add class to mapping.
+     *
+     * @access  public
+     * @param   string  $className  Class name
+     * @param   string  $classPath  Full path to class
+     */
+    public static function mapClass($className, $classPath)
+    {
+        static::$classes[$className] = $classPath;
+    }
+
+    /**
+     * Add multiple classes to mapping.
+     *
+     * @access  public
+     * @param   array   $classes  Array of classes to map (key = class name and value = class path)
+     */
+    public static function mapClasses(array $classes)
+    {
+        foreach($classes as $name => $path)
+        {
+            static::$classes[$name] = $path;
+        }
+    }
+
+    /**
+     * Adds a PSR-0 directory path.
+     *
+     * @access  public
+     * @param   string  $path  Path to PSR-0 directory
+     */
+    public static function directory($path)
+    {
+        static::$directories[] = rtrim($path, '/');
+        echo rtrim($path, '/');
+    }
+
+    /**
+     * Registers a namespace.
+     *
+     * @access  public
+     * @param   string  $namespace  Namespace
+     * @param   string  $path       Path
+     */
+    public static function registerNamespace($namespace, $path)
+    {
+        static::$namespaces[trim($namespace, '\\') . '\\'] = rtrim($path, '/');
+    }
+
+    /**
+     * Set an alias for a class.
+     *
+     * @access  public
+     * @param   string  $alias      Class alias
+     * @param   string  $className  Class name
+     */
+    public static function alias($alias, $className)
+    {
+        static::$aliases[$alias] = $className;
+    }
+
+    /**
+     * Try to load a PSR-0 compatible class.
+     *
+     * @access  protected
+     * @param   string     $className  Class name
+     * @param   string     $directory  (Optional) Overrides the array of PSR-0 paths
+     * @return  boolean
+     */
+    protected static function loadPSR0($className, $directory = null)
+    {
+        $classPath = '';
+
+        if(($pos = strripos($className, '\\')) !== false)
+        {
+            $namespace = substr($className, 0, $pos);
+            $className = substr($className, $pos + 1);
+            $classPath = str_replace('\\', '/', $namespace) . '/';
+        }
+
+        $classPath .= str_replace('_', '/', $className) . '.php';
+
+        $directories = ($directory === null) ? static::$directories : array($directory);
+
+        foreach($directories as $directory)
+        {
+            if(file_exists($directory . '/' . $classPath))
+            {
+                include($directory . '/' . $classPath);
+
+                return true;
+            }   
+        }
+
+        return false;
+    }
+
+
+    /**
+     * Autoloader.
+     *
+     * @access  public
+     * @param   string   $className  Class name
+     * @return  boolean
+     */
+    public static function load($className)
+    {
+        $className = ltrim($className, '\\');
+
+        // Try to autoload an aliased class
+
+        if(isset(static::$aliases[$className]))
+        {
+            return class_alias(static::$aliases[$className], $className);
+        }
+
+        // Try to load a mapped class
+
+        if(isset(static::$classes[$className]) && file_exists(static::$classes[$className]))
+        {
+            include static::$classes[$className];
+
+            return true;
+        }
+
+        // Try to load class from a registered namespace
+
+        foreach(static::$namespaces as $namespace => $path)
+        {
+            if(strpos($className, $namespace) === 0)
+            {
+                if(static::loadPSR0(substr($className, strlen($namespace)), $path))
+                {
+                    return true;
+                }
+            }
+        }
+
+        // Try to load a PSR-0 compatible class
+        // The second call to the loadPSR0 method is used to autoload legacy code
+        if (static::loadPSR0($className) || static::loadPSR0(strtolower($className)))
+        {
+            return true;
+        }
+        
+        return false;
+    }
+}