inc/filters.php

   1 <?php
   2 /************************************************************************
   3  * MXChange v0.2.1                                    Start: 12/16/2008 *
   4  * ===============                              Last change: 12/16/2008 *
   5  *                                                                      *
   6  * -------------------------------------------------------------------- *
   7  * File              : filters.php                                      *
   8  * -------------------------------------------------------------------- *
   9  * Short description : Functions for filter system                      *
  10  * -------------------------------------------------------------------- *
  11  * Kurzbeschreibung  : Funktionen fuer Filter-System                    *
  12  * -------------------------------------------------------------------- *
  13  *                                                                      *
  14  * -------------------------------------------------------------------- *
  15  * Copyright (c) 2003 - 2008 by Roland Haeder                           *
  16  * For more information visit: http://www.mxchange.org                  *
  17  *                                                                      *
  18  * This program is free software; you can redistribute it and/or modify *
  19  * it under the terms of the GNU General Public License as published by *
  20  * the Free Software Foundation; either version 2 of the License, or    *
  21  * (at your option) any later version.                                  *
  22  *                                                                      *
  23  * This program is distributed in the hope that it will be useful,      *
  24  * but WITHOUT ANY WARRANTY; without even the implied warranty of       *
  25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
  26  * GNU General Public License for more details.                         *
  27  *                                                                      *
  28  * You should have received a copy of the GNU General Public License    *
  29  * along with this program; if not, write to the Free Software          *
  30  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,               *
  31  * MA  02110-1301  USA                                                  *
  32  ************************************************************************/
  33
  34 // Some security stuff...
  35 if (!defined('__SECURITY')) {
  36         $INC = substr(dirname(__FILE__), 0, strpos(dirname(__FILE__), "/inc") + 4)."/security.php";
  37         require($INC);
  38 }
  39
  40 // Init "generic filter system"
  41 function INIT_FILTER_SYSTEM() {
  42         global $filters, $loadedFilters;
  43
  44         // Is the filter already initialized?
  45         if ((isset($filters)) && (is_array($filters))) {
  46                 // Then abort here
  47                 ADD_FATAL(FILTER_FAILED_ALREADY_INIT);
  48                 return false;
  49         } // END - if
  50
  51         // Init the filter system (just some ideas)
  52         $filters = array(
  53                 // Filters for pre-init phase
  54                 'preinit'   => array(),
  55                 // Filters for post-init phase
  56                 'postinit'  => array(),
  57                 // Filters for shutdown phase
  58                 'shutdown'  => array()
  59         );
  60
  61         // Init loaded filters
  62         $loadedFilters =  array();
  63
  64         // Load all saved filers if sql_patches is updated
  65         if (GET_EXT_VERSION("sql_patches") >= "0.5.9") {
  66                 // Load all active filers
  67                 $result = SQL_QUERY("SELECT `filter_name`, `filter_function`, `filter_active`
  68 FROM `"._MYSQL_PREFIX."_filters`
  69 ORDER BY `filter_id` ASC", __FILE__, __LINE__);
  70
  71                 // Are there entries?
  72                 if (SQL_NUMROWS($result) > 0) {
  73                         // Load all filters
  74                         while ($filterArray = SQL_FETCHARRAY($result)) {
  75                                 // Mark this filter as loaded (from database)
  76                                 $loadedFilters[$filterArray['filter_name']][$filterArray['filter_function']] = true;
  77
  78                                 // Set this filter
  79                                 $filters[$filterArray['filter_name']][$filterArray['filter_function']] = $filterArray['filter_active'];
  80                         } // END - while
  81                 } // END - if
  82
  83                 // Free result
  84                 SQL_FREERESULT($result);
  85         } // END - if
  86
  87         // @TODO Find some more init/shutdown filter functions
  88
  89         // Register shutdown filters
  90         REGISTER_FILTER('shutdown', 'FLUSH_FILTERS');
  91         REGISTER_FILTER('shutdown', 'SHUTDOWN_DATABASE');
  92 }
  93
  94 // "Registers" a new filter function
  95 function REGISTER_FILTER ($filterName, $filterFunction, $silentAbort = true, $force = false) {
  96         global $filters;
  97
  98         // Extend the filter function name
  99         $filterFunction = sprintf("FILTER_%s", strtoupper($filterFunction));
 100
 101         // Is that filter already there?
 102         if ((isset($filters[$filterName][$filterFunction])) && (!$force)) {
 103                 // Then abort here
 104                 if (!$silentAbort) {
 105                         ADD_FATAL(sprintf(FILTER_FAILED_ALREADY_ADDED, $filterFunction, $filterName));
 106                 } // END - if
 107
 108                 // Abort here
 109                 return false;
 110         } // END - if
 111
 112         // Is the function there?
 113         if (!function_exists($filterFunction)) {
 114                 // Then abort here
 115                 ADD_FATAL(sprintf(FILTER_FAILED_NOT_FOUND, $filterFunction, $filterName));
 116                 return false;
 117         } // END - if
 118
 119         // Simply add it to the array
 120         $filters[$filterName][$filterFunction] = "Y";
 121 }
 122
 123 // "Unregisters" a filter from the given chain
 124 function UNREGISTER_FILTER ($filterName, $filterFunction, $force = false) {
 125         global $filters;
 126
 127         // Extend the filter function name
 128         $filterFunction = sprintf("FILTER_%s", strtoupper($filterFunction));
 129
 130         // Is that filter there?
 131         if ((!isset($filters[$filterName][$filterFunction])) && (!$force)) {
 132                 // Not found, so abort here
 133                 ADD_FATAL(sprintf(FILTER_FAILED_NOT_REMOVED, $filterFunction, $filterName));
 134                 return false;
 135         } // END - if
 136
 137         // Mark for filter removal
 138         $filters[$filterName][$filterFunction] = "R";
 139 }
 140
 141 // "Runs" the given filters, data is optional and can be any type of data
 142 function RUN_FILTER ($filterName, $data = null, $silentAbort = true) {
 143         global $filters;
 144
 145         // Is that filter chain there?
 146         if (!isset($filters[$filterName])) {
 147                 // Then abort here (quick'N'dirty hack)
 148                 if ((!$silentAbort) && (defined('FILTER_FAILED_NO_FILTER_FOUND'))) {
 149                         ADD_FATAL(sprintf(FILTER_FAILED_NO_FILTER_FOUND, $filterName));
 150                 } // END - if
 151
 152                 // Abort here
 153                 return false;
 154         } // END - if
 155
 156         // Default return value
 157         $returnValue = $data;
 158
 159         // Then run all filters
 160         foreach ($filters[$filterName] as $filterFunction=>$active) {
 161                 // Debug message
 162                 /* DEBUG: */ echo __FUNCTION__."(<font color=\"#0000aa\">".__LINE__."</font>): name={$filterName}, func={$filterFunction}, active={$active}<br />\n";
 163
 164                 // Is the filter active?
 165                 if ($active == "Y") {
 166                         // Call the filter chain
 167                         $returnValue = call_user_func_array($filterFunction, array($returnValue));
 168                 } // END - if
 169         } // END - foreach
 170
 171         // Return the filtered content
 172         return $returnValue;
 173 }
 174
 175 // -----------------------------------------------------------------------------
 176 // Generic filter functions we always need
 177 // -----------------------------------------------------------------------------
 178
 179 // Filter for flushing all new filters to the database
 180 function FILTER_FLUSH_FILTERS () {
 181         global $filters, $link, $loadedFilters;
 182
 183         // Is a database link here and not in installation mode?
 184         if ((!is_resource($link)) && (!isBooleanConstantAndTrue('mxchange_installing'))) {
 185                 // Abort here
 186                 ADD_FATAL(sprintf(FILTER_FLUSH_FAILED_NO_DATABASE, $filterFunction, $filterName));
 187                 return false;
 188         } // END - if
 189
 190         // Is the extension sql_patches updated?
 191         if (EXT_VERSION_IS_OLDER("sql_patches", "0.5.9")) {
 192                 // Abort silently here
 193                 return false;
 194         } // END - if
 195
 196         // Nothing is added/remove by default
 197         $inserted = 0; $removed = 0;
 198
 199         // Prepare SQL queries
 200         $insertSQL = "INSERT INTO `"._MYSQL_PREFIX."_filters` (`filter_name`,`filter_function`,`filter_active`) VALUES";
 201         $removeSQL = "DELETE LOW_PRIORITY FROM `"._MYSQL_PREFIX."_filters` WHERE";
 202
 203         // Write all filters to database
 204         foreach ($filters as $filterName => $filterArray) {
 205                 // Walk through all filters
 206                 foreach ($filterArray as $filterFunction => $active) {
 207                         // Is this filter loaded?
 208                         if (!isset($loadedFilters[$filterName][$filterFunction])) {
 209                                 // Add this filter (all filters are active by default)
 210                                 $insertSQL .= sprintf("('%s','%s','Y'),", $filterName, $filterFunction);
 211                                 $inserted++;
 212                         } elseif ($active == "R") {
 213                                 // Remove this filter
 214                                 $removeSQL .= sprintf(" (`filter_name`='%s' AND `filter_function`='%s') OR", $filterName, $filterFunction);
 215                                 $removed++;
 216                         }
 217                 } // END - foreach
 218         } // END - foreach
 219
 220         // Something has been added?
 221         if ($inserted > 0) {
 222                 // Finish SQL command
 223                 $insertSQL = substr($insertSQL, 0, -1);
 224
 225                 // And run it
 226                 SQL_QUERY($insertSQL, __FILE__, __LINE__);
 227         } // END - if
 228
 229         // Something has been removed?
 230         if ($removed > 0) {
 231                 // Finish SQL command
 232                 $removeSQL = substr($removeSQL, 0, -2) . "LIMIT ".$removed;
 233
 234                 // And run it
 235                 SQL_QUERY($removeSQL, __FILE__, __LINE__);
 236         } // END - if
 237 }
 238
 239 // Filter for shutting down the database link
 240 function FILTER_SHUTDOWN_DATABASE () {
 241         global $link;
 242
 243         if (is_resource($link)) {
 244                 // Close link
 245                 SQL_CLOSE($link, __FILE__, __LINE__);
 246         } else {
 247                 // No database link
 248                 ADD_FATAL(NO_DB_LINK);
 249         }
 250 }
 251
 252 //
 253 ?>