libraries/Hooks.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 4.3.2 or newer
   6  *
   7  * @package             CodeIgniter
   8  * @author              ExpressionEngine Dev Team
   9  * @copyright   Copyright (c) 2008 - 2009, 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 Hooks Class
  20  *
  21  * Provides a mechanism to extend the base system without hacking.  Most of
  22  * this class is borrowed from Paul's Extension class in ExpressionEngine.
  23  *
  24  * @package             CodeIgniter
  25  * @subpackage  Libraries
  26  * @category    Libraries
  27  * @author              ExpressionEngine Dev Team
  28  * @link                http://codeigniter.com/user_guide/libraries/encryption.html
  29  */
  30 class CI_Hooks {
  31
  32         var $enabled            = FALSE;
  33         var $hooks              = array();
  34         var $in_progress        = FALSE;
  35
  36         /**
  37          * Constructor
  38          *
  39          */
  40         function CI_Hooks()
  41         {
  42                 $this->_initialize();
  43                 log_message('debug', "Hooks Class Initialized");
  44         }
  45
  46         // --------------------------------------------------------------------
  47
  48         /**
  49          * Initialize the Hooks Preferences
  50          *
  51          * @access      private
  52          * @return      void
  53          */
  54         function _initialize()
  55         {
  56                 $CFG =& load_class('Config');
  57
  58                 // If hooks are not enabled in the config file
  59                 // there is nothing else to do
  60
  61                 if ($CFG->item('enable_hooks') == FALSE)
  62                 {
  63                         return;
  64                 }
  65
  66                 // Grab the "hooks" definition file.
  67                 // If there are no hooks, we're done.
  68
  69                 @include(APPPATH.'config/hooks'.EXT);
  70
  71                 if ( ! isset($hook) OR ! is_array($hook))
  72                 {
  73                         return;
  74                 }
  75
  76                 $this->hooks =& $hook;
  77                 $this->enabled = TRUE;
  78         }
  79
  80         // --------------------------------------------------------------------
  81
  82         /**
  83          * Call Hook
  84          *
  85          * Calls a particular hook
  86          *
  87          * @access      private
  88          * @param       string  the hook name
  89          * @return      mixed
  90          */
  91         function _call_hook($which = '')
  92         {
  93                 if ( ! $this->enabled OR ! isset($this->hooks[$which]))
  94                 {
  95                         return FALSE;
  96                 }
  97
  98                 if (isset($this->hooks[$which][0]) AND is_array($this->hooks[$which][0]))
  99                 {
 100                         foreach ($this->hooks[$which] as $val)
 101                         {
 102                                 $this->_run_hook($val);
 103                         }
 104                 }
 105                 else
 106                 {
 107                         $this->_run_hook($this->hooks[$which]);
 108                 }
 109
 110                 return TRUE;
 111         }
 112
 113         // --------------------------------------------------------------------
 114
 115         /**
 116          * Run Hook
 117          *
 118          * Runs a particular hook
 119          *
 120          * @access      private
 121          * @param       array   the hook details
 122          * @return      bool
 123          */
 124         function _run_hook($data)
 125         {
 126                 if ( ! is_array($data))
 127                 {
 128                         return FALSE;
 129                 }
 130
 131                 // -----------------------------------
 132                 // Safety - Prevents run-away loops
 133                 // -----------------------------------
 134
 135                 // If the script being called happens to have the same
 136                 // hook call within it a loop can happen
 137
 138                 if ($this->in_progress == TRUE)
 139                 {
 140                         return;
 141                 }
 142
 143                 // -----------------------------------
 144                 // Set file path
 145                 // -----------------------------------
 146
 147                 if ( ! isset($data['filepath']) OR ! isset($data['filename']))
 148                 {
 149                         return FALSE;
 150                 }
 151
 152                 $filepath = APPPATH.$data['filepath'].'/'.$data['filename'];
 153
 154                 if ( ! file_exists($filepath))
 155                 {
 156                         return FALSE;
 157                 }
 158
 159                 // -----------------------------------
 160                 // Set class/function name
 161                 // -----------------------------------
 162
 163                 $class          = FALSE;
 164                 $function       = FALSE;
 165                 $params         = '';
 166
 167                 if (isset($data['class']) AND $data['class'] != '')
 168                 {
 169                         $class = $data['class'];
 170                 }
 171
 172                 if (isset($data['function']))
 173                 {
 174                         $function = $data['function'];
 175                 }
 176
 177                 if (isset($data['params']))
 178                 {
 179                         $params = $data['params'];
 180                 }
 181
 182                 if ($class === FALSE AND $function === FALSE)
 183                 {
 184                         return FALSE;
 185                 }
 186
 187                 // -----------------------------------
 188                 // Set the in_progress flag
 189                 // -----------------------------------
 190
 191                 $this->in_progress = TRUE;
 192
 193                 // -----------------------------------
 194                 // Call the requested class and/or function
 195                 // -----------------------------------
 196
 197                 if ($class !== FALSE)
 198                 {
 199                         if ( ! class_exists($class))
 200                         {
 201                                 require($filepath);
 202                         }
 203
 204                         $HOOK = new $class;
 205                         $HOOK->$function($params);
 206                 }
 207                 else
 208                 {
 209                         if ( ! function_exists($function))
 210                         {
 211                                 require($filepath);
 212                         }
 213
 214                         $function($params);
 215                 }
 216
 217                 $this->in_progress = FALSE;
 218                 return TRUE;
 219         }
 220
 221 }
 222
 223 // END CI_Hooks class
 224
 225 /* End of file Hooks.php */
 226 /* Location: ./system/libraries/Hooks.php */