system/core/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 5.1.6 or newer
   6  *
   7  * @package             CodeIgniter
   8  * @author              ExpressionEngine Dev Team
   9  * @copyright   Copyright (c) 2008 - 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 Hooks Class
  20  *
  21  * Provides a mechanism to extend the base system without hacking.
  22  *
  23  * @package             CodeIgniter
  24  * @subpackage  Libraries
  25  * @category    Libraries
  26  * @author              ExpressionEngine Dev Team
  27  * @link                http://codeigniter.com/user_guide/libraries/encryption.html
  28  */
  29 class CI_Hooks {
  30
  31         var $enabled            = FALSE;
  32         var $hooks                      = array();
  33         var $in_progress        = FALSE;
  34
  35         /**
  36          * Constructor
  37          *
  38          */
  39         function __construct()
  40         {
  41                 $this->_initialize();
  42                 log_message('debug', "Hooks Class Initialized");
  43         }
  44
  45         // --------------------------------------------------------------------
  46
  47         /**
  48          * Initialize the Hooks Preferences
  49          *
  50          * @access      private
  51          * @return      void
  52          */
  53         function _initialize()
  54         {
  55                 $CFG =& load_class('Config', 'core');
  56
  57                 // If hooks are not enabled in the config file
  58                 // there is nothing else to do
  59
  60                 if ($CFG->item('enable_hooks') == FALSE)
  61                 {
  62                         return;
  63                 }
  64
  65                 // Grab the "hooks" definition file.
  66                 // If there are no hooks, we're done.
  67
  68                 if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/hooks'.EXT))
  69                 {
  70                     include(APPPATH.'config/'.ENVIRONMENT.'/hooks'.EXT);
  71                 }
  72                 elseif (is_file(APPPATH.'config/hooks'.EXT))
  73                 {
  74                         include(APPPATH.'config/hooks'.EXT);
  75                 }
  76
  77
  78                 if ( ! isset($hook) OR ! is_array($hook))
  79                 {
  80                         return;
  81                 }
  82
  83                 $this->hooks =& $hook;
  84                 $this->enabled = TRUE;
  85         }
  86
  87         // --------------------------------------------------------------------
  88
  89         /**
  90          * Call Hook
  91          *
  92          * Calls a particular hook
  93          *
  94          * @access      private
  95          * @param       string  the hook name
  96          * @return      mixed
  97          */
  98         function _call_hook($which = '')
  99         {
 100                 if ( ! $this->enabled OR ! isset($this->hooks[$which]))
 101                 {
 102                         return FALSE;
 103                 }
 104
 105                 if (isset($this->hooks[$which][0]) AND is_array($this->hooks[$which][0]))
 106                 {
 107                         foreach ($this->hooks[$which] as $val)
 108                         {
 109                                 $this->_run_hook($val);
 110                         }
 111                 }
 112                 else
 113                 {
 114                         $this->_run_hook($this->hooks[$which]);
 115                 }
 116
 117                 return TRUE;
 118         }
 119
 120         // --------------------------------------------------------------------
 121
 122         /**
 123          * Run Hook
 124          *
 125          * Runs a particular hook
 126          *
 127          * @access      private
 128          * @param       array   the hook details
 129          * @return      bool
 130          */
 131         function _run_hook($data)
 132         {
 133                 if ( ! is_array($data))
 134                 {
 135                         return FALSE;
 136                 }
 137
 138                 // -----------------------------------
 139                 // Safety - Prevents run-away loops
 140                 // -----------------------------------
 141
 142                 // If the script being called happens to have the same
 143                 // hook call within it a loop can happen
 144
 145                 if ($this->in_progress == TRUE)
 146                 {
 147                         return;
 148                 }
 149
 150                 // -----------------------------------
 151                 // Set file path
 152                 // -----------------------------------
 153
 154                 if ( ! isset($data['filepath']) OR ! isset($data['filename']))
 155                 {
 156                         return FALSE;
 157                 }
 158
 159                 $filepath = APPPATH.$data['filepath'].'/'.$data['filename'];
 160
 161                 if ( ! file_exists($filepath))
 162                 {
 163                         return FALSE;
 164                 }
 165
 166                 // -----------------------------------
 167                 // Set class/function name
 168                 // -----------------------------------
 169
 170                 $class          = FALSE;
 171                 $function       = FALSE;
 172                 $params         = '';
 173
 174                 if (isset($data['class']) AND $data['class'] != '')
 175                 {
 176                         $class = $data['class'];
 177                 }
 178
 179                 if (isset($data['function']))
 180                 {
 181                         $function = $data['function'];
 182                 }
 183
 184                 if (isset($data['params']))
 185                 {
 186                         $params = $data['params'];
 187                 }
 188
 189                 if ($class === FALSE AND $function === FALSE)
 190                 {
 191                         return FALSE;
 192                 }
 193
 194                 // -----------------------------------
 195                 // Set the in_progress flag
 196                 // -----------------------------------
 197
 198                 $this->in_progress = TRUE;
 199
 200                 // -----------------------------------
 201                 // Call the requested class and/or function
 202                 // -----------------------------------
 203
 204                 if ($class !== FALSE)
 205                 {
 206                         if ( ! class_exists($class))
 207                         {
 208                                 require($filepath);
 209                         }
 210
 211                         $HOOK = new $class;
 212                         $HOOK->$function($params);
 213                 }
 214                 else
 215                 {
 216                         if ( ! function_exists($function))
 217                         {
 218                                 require($filepath);
 219                         }
 220
 221                         $function($params);
 222                 }
 223
 224                 $this->in_progress = FALSE;
 225                 return TRUE;
 226         }
 227
 228 }
 229
 230 // END CI_Hooks class
 231
 232 /* End of file Hooks.php */
 233 /* Location: ./system/core/Hooks.php */