added Driver lib

2 files changed, 255 insertions, 0 deletions

diff --git a/system/core/Loader.php b/system/core/Loader.php
index f70ee0334..c399f296d 100644
--- a/system/core/Loader.php
+++ b/system/core/Loader.php
@@ -544,6 +544,29 @@ class CI_Loader {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Driver
+	 *
+	 * Loads a driver library
+	 *
+	 * @param	string	the name of the class
+	 * @param	mixed	the optional parameters
+	 * @param	string	an optional object name
+	 * @return	void
+	 */
+	function driver($library = '', $params = NULL, $object_name = NULL)
+	{
+		if ( ! class_exists('CI_Driver_Library'))
+		{
+			// we aren't instantiating an object here, that'll be done by the Library itself
+			require_once BASEPATH.'libraries/Driver'.EXT;
+		}
+		
+		return $this->library($library, $params, $object_name);
+	}
+
+	// --------------------------------------------------------------------
+	
+	/**
 	 * Add Package Path
 	 *
 	 * Prepends a parent path to the library, model, helper, and config path arrays
diff --git a/system/libraries/Driver.php b/system/libraries/Driver.php
new file mode 100644
index 000000000..07ef2e724
--- /dev/null
+++ b/system/libraries/Driver.php
@@ -0,0 +1,232 @@
+<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
+/**
+ * CodeIgniter
+ *
+ * An open source application development framework for PHP 4.3.2 or newer
+ *
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
+ * @copyright	Copyright (c) 2006 - 2010, EllisLab, Inc.
+ * @license		http://codeigniter.com/user_guide/license.html
+ * @link		http://codeigniter.com
+ * @since		Version 1.0
+ * @filesource
+ */
+
+// ------------------------------------------------------------------------
+
+/**
+ * CodeIgniter Driver Library Class
+ *
+ * This class enables you to create "Driver" libraries that add runtime ability
+ * to extend the capabilities of a class via additional driver objects
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Libraries
+ * @author		EllisLab Dev Team
+ * @link		
+ */
+class CI_Driver_Library {
+
+	protected $valid_drivers	= array();
+	protected static $lib_name;
+	
+	// The first time a child is used it won't exist, so we instantiate it
+	// subsequents calls will go straight to the proper child.
+	function __get($child)
+	{
+		if (! isset($this->lib_name))
+		{
+			$this->lib_name = get_class($this);				
+		}
+
+		// The class will be prefixed with the parent lib
+		$child_class = $this->lib_name.'_'.$child;
+		
+		if (in_array(strtolower($child_class), array_map('strtolower', $this->valid_drivers)))
+		{
+			// check and see if the driver is in a separate file
+			if ( ! class_exists($child_class))
+			{
+				// check application path first
+				foreach (array(APPPATH, BASEPATH) as $path)
+				{
+					// and check for case sensitivity of both the parent and child libs
+					foreach (array(ucfirst($this->lib_name), strtolower($this->lib_name)) as $lib)
+					{
+						// loves me some nesting!
+						foreach (array(ucfirst($child_class), strtolower($child_class)) as $class)
+						{
+							$filepath = $path.'libraries/'.$this->lib_name.'/drivers/'.$child_class.EXT;
+
+							if (file_exists($filepath))
+							{
+								include_once $filepath;
+								break;
+							}							
+						}
+					}
+				}
+				
+				// it's a valid driver, but the file simply can't be found
+				if ( ! class_exists($child_class))
+				{
+					log_message('error', "Unable to load the requested driver: ".$child_class);
+					show_error("Unable to load the requested driver: ".$child_class);
+				}
+			}
+
+			$obj = new $child_class;
+			$obj->decorate($this);
+			$this->$child = $obj;
+			return $this->$child;
+		}
+		
+		// The requested driver isn't valid!
+		log_message('error', "Invalid driver requested: ".$child_class);
+		show_error("Invalid driver requested: ".$child_class);
+	}
+	
+	// --------------------------------------------------------------------
+	
+}
+// END CI_Driver_Library CLASS
+
+
+/**
+ * CodeIgniter Driver Class
+ *
+ * This class enables you to create drivers for a Library based on the Driver Library.
+ * It handles the drivers' access to the parent library
+ *
+ * @package		CodeIgniter
+ * @subpackage	Libraries
+ * @category	Libraries
+ * @author		EllisLab Dev Team
+ * @link		
+ */
+class CI_Driver {
+	protected $parent;
+			
+	private $methods = array();
+	private $properties = array();
+
+	private static $reflections = array();
+
+	/**
+	 * Decorate
+	 *
+	 * Decorates the child with the parent driver lib's methods and properties
+	 *
+	 * @access	public
+	 * @param	object
+	 * @return	void
+	 */
+	function decorate($parent)
+	{
+		$this->parent = $parent;
+		
+		// Lock down attributes to what is defined in the class
+		// and speed up references in magic methods
+		
+		$class_name = get_class($parent);
+		
+		if ( ! isset(self::$reflections[$class_name]))
+		{
+			$r = new ReflectionObject($parent);
+			
+			foreach ($r->getMethods() as $method)
+			{
+				if ($method->isPublic())
+				{
+					$this->methods[] = $method->getName();
+				}
+			}
+
+			foreach($r->getProperties() as $prop)
+			{
+				if ($prop->isPublic())
+				{
+					$this->properties[] = $prop->getName();
+				}
+			}
+			
+			self::$reflections[$class_name] = array($this->methods, $this->properties);
+		}
+		else
+		{
+			list($this->methods, $this->properties) = self::$reflections[$class_name];
+		}
+	}
+	
+	// --------------------------------------------------------------------
+	
+	/**
+	 * __call magic method
+	 *
+	 * Handles access to the parent driver library's methods
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	array
+	 * @return	mixed
+	 */
+	public function __call($method, $args = array())
+	{
+		if (in_array($method, $this->methods))
+		{
+			return call_user_func_array(array($this->parent, $method), $args);
+		}
+
+		$trace = debug_backtrace();
+		_exception_handler(E_ERROR, "No such method '{$method}'", $trace[1]['file'], $trace[1]['line']);
+		exit;
+	}
+
+	// --------------------------------------------------------------------
+	
+	/**
+	 * __get magic method
+	 *
+	 * Handles reading of the parent driver library's properties
+	 *
+	 * @access	public
+	 * @param	string
+	 * @return	mixed
+	 */
+	function __get($var)
+	{
+		if (in_array($var, $this->properties))
+		{
+			return $this->parent->$var;
+		}
+	}
+
+	// --------------------------------------------------------------------
+	
+	/**
+	 * __set magic method
+	 *
+	 * Handles writing to the parent driver library's properties
+	 *
+	 * @access	public
+	 * @param	string
+	 * @param	array
+	 * @return	mixed
+	 */
+	function __set($var, $val)
+	{
+		if (in_array($var, $this->properties))
+		{
+			$this->parent->$var = $val;
+		}
+	}
+	
+	// --------------------------------------------------------------------
+	
+}
+// END CI_Driver CLASS
+
+/* End of file Driver.php */
+/* Location: ./system/libraries/Driver.php */
\ No newline at end of file