system/libraries/Driver.php

   1 <?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
   2 /**
   3  * CodeIgniter
   4  *
   5  * An open source application development framework for PHP 5.1.6 or newer
   6  *
   7  * @package             CodeIgniter
   8  * @author              EllisLab Dev Team
   9  * @copyright   Copyright (c) 2006 - 2011, EllisLab, Inc.
  10  * @license             http://codeigniter.com/user_guide/license.html
  11  * @link                http://codeigniter.com
  12  * @since               Version 1.0
  13  * @filesource
  14  */
  15
  16 // ------------------------------------------------------------------------
  17
  18 /**
  19  * CodeIgniter Driver Library Class
  20  *
  21  * This class enables you to create "Driver" libraries that add runtime ability
  22  * to extend the capabilities of a class via additional driver objects
  23  *
  24  * @package             CodeIgniter
  25  * @subpackage  Libraries
  26  * @category    Libraries
  27  * @author              EllisLab Dev Team
  28  * @link
  29  */
  30 class CI_Driver_Library {
  31
  32         protected $valid_drivers        = array();
  33         protected static $lib_name;
  34
  35         // The first time a child is used it won't exist, so we instantiate it
  36         // subsequents calls will go straight to the proper child.
  37         function __get($child)
  38         {
  39                 if ( ! isset($this->lib_name))
  40                 {
  41                         $this->lib_name = get_class($this);
  42                 }
  43
  44                 // The class will be prefixed with the parent lib
  45                 $child_class = $this->lib_name.'_'.$child;
  46
  47                 // Remove the CI_ prefix and lowercase
  48                 $lib_name = strtolower(preg_replace('/^CI_/', '', $this->lib_name));
  49                 $driver_name = strtolower(preg_replace('/^CI_/', '', $child_class));
  50
  51                 if (in_array($driver_name, array_map('strtolower', $this->valid_drivers)))
  52                 {
  53                         // check and see if the driver is in a separate file
  54                         if ( ! class_exists($child_class))
  55                         {
  56                                 // check application path first
  57                                 foreach (array(APPPATH, BASEPATH) as $path)
  58                                 {
  59                                         // loves me some nesting!
  60                                         foreach (array(ucfirst($driver_name), $driver_name) as $class)
  61                                         {
  62                                                 $filepath = $path.'libraries/'.$lib_name.'/drivers/'.$class.EXT;
  63
  64                                                 if (file_exists($filepath))
  65                                                 {
  66                                                         include_once $filepath;
  67                                                         break;
  68                                                 }
  69                                         }
  70                                 }
  71
  72                                 // it's a valid driver, but the file simply can't be found
  73                                 if ( ! class_exists($child_class))
  74                                 {
  75                                         log_message('error', "Unable to load the requested driver: ".$child_class);
  76                                         show_error("Unable to load the requested driver: ".$child_class);
  77                                 }
  78                         }
  79
  80                         $obj = new $child_class;
  81                         $obj->decorate($this);
  82                         $this->$child = $obj;
  83                         return $this->$child;
  84                 }
  85
  86                 // The requested driver isn't valid!
  87                 log_message('error', "Invalid driver requested: ".$child_class);
  88                 show_error("Invalid driver requested: ".$child_class);
  89         }
  90
  91         // --------------------------------------------------------------------
  92
  93 }
  94 // END CI_Driver_Library CLASS
  95
  96
  97 /**
  98  * CodeIgniter Driver Class
  99  *
 100  * This class enables you to create drivers for a Library based on the Driver Library.
 101  * It handles the drivers' access to the parent library
 102  *
 103  * @package             CodeIgniter
 104  * @subpackage  Libraries
 105  * @category    Libraries
 106  * @author              EllisLab Dev Team
 107  * @link
 108  */
 109 class CI_Driver {
 110         protected $parent;
 111
 112         private $methods = array();
 113         private $properties = array();
 114
 115         private static $reflections = array();
 116
 117         /**
 118          * Decorate
 119          *
 120          * Decorates the child with the parent driver lib's methods and properties
 121          *
 122          * @param       object
 123          * @return      void
 124          */
 125         public function decorate($parent)
 126         {
 127                 $this->parent = $parent;
 128
 129                 // Lock down attributes to what is defined in the class
 130                 // and speed up references in magic methods
 131
 132                 $class_name = get_class($parent);
 133
 134                 if ( ! isset(self::$reflections[$class_name]))
 135                 {
 136                         $r = new ReflectionObject($parent);
 137
 138                         foreach ($r->getMethods() as $method)
 139                         {
 140                                 if ($method->isPublic())
 141                                 {
 142                                         $this->methods[] = $method->getName();
 143                                 }
 144                         }
 145
 146                         foreach ($r->getProperties() as $prop)
 147                         {
 148                                 if ($prop->isPublic())
 149                                 {
 150                                         $this->properties[] = $prop->getName();
 151                                 }
 152                         }
 153
 154                         self::$reflections[$class_name] = array($this->methods, $this->properties);
 155                 }
 156                 else
 157                 {
 158                         list($this->methods, $this->properties) = self::$reflections[$class_name];
 159                 }
 160         }
 161
 162         // --------------------------------------------------------------------
 163
 164         /**
 165          * __call magic method
 166          *
 167          * Handles access to the parent driver library's methods
 168          *
 169          * @access      public
 170          * @param       string
 171          * @param       array
 172          * @return      mixed
 173          */
 174         public function __call($method, $args = array())
 175         {
 176                 if (in_array($method, $this->methods))
 177                 {
 178                         return call_user_func_array(array($this->parent, $method), $args);
 179                 }
 180
 181                 $trace = debug_backtrace();
 182                 _exception_handler(E_ERROR, "No such method '{$method}'", $trace[1]['file'], $trace[1]['line']);
 183                 exit;
 184         }
 185
 186         // --------------------------------------------------------------------
 187
 188         /**
 189          * __get magic method
 190          *
 191          * Handles reading of the parent driver library's properties
 192          *
 193          * @param       string
 194          * @return      mixed
 195          */
 196         public function __get($var)
 197         {
 198                 if (in_array($var, $this->properties))
 199                 {
 200                         return $this->parent->$var;
 201                 }
 202         }
 203
 204         // --------------------------------------------------------------------
 205
 206         /**
 207          * __set magic method
 208          *
 209          * Handles writing to the parent driver library's properties
 210          *
 211          * @param       string
 212          * @param       array
 213          * @return      mixed
 214          */
 215         public function __set($var, $val)
 216         {
 217                 if (in_array($var, $this->properties))
 218                 {
 219                         $this->parent->$var = $val;
 220                 }
 221         }
 222
 223         // --------------------------------------------------------------------
 224
 225 }
 226 // END CI_Driver CLASS
 227
 228 /* End of file Driver.php */
 229 /* Location: ./system/libraries/Driver.php */