includes/Hooks.php

   1 <?php
   2 /**
   3  * Hooks.php -- a tool for running hook functions
   4  * Copyright 2004, 2005 Evan Prodromou <evan@wikitravel.org>.
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, write to the Free Software
  18  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  *
  20  * @author Evan Prodromou <evan@wikitravel.org>
  21  * @package MediaWiki
  22  * @see hooks.txt
  23  */
  24
  25 if (defined('MEDIAWIKI')) {
  26
  27         /**
  28          * Because programmers assign to $wgHooks, we need to be very
  29          * careful about its contents. So, there's a lot more error-checking
  30          * in here than would normally be necessary.
  31          */
  32
  33         function wfRunHooks($event, $args) {
  34
  35                 global $wgHooks;
  36
  37                 if (!is_array($wgHooks)) {
  38                         wfDieDebugBacktrace("Global hooks array is not an array!\n");
  39                         return false;
  40                 }
  41
  42                 if (!array_key_exists($event, $wgHooks)) {
  43                         return true;
  44                 }
  45
  46                 if (!is_array($wgHooks[$event])) {
  47                         wfDieDebugBacktrace("Hooks array for event '$event' is not an array!\n");
  48                         return false;
  49                 }
  50
  51                 foreach ($wgHooks[$event] as $hook) {
  52
  53                         $object = NULL;
  54                         $method = NULL;
  55                         $func = NULL;
  56                         $data = NULL;
  57                         $have_data = false;
  58
  59                         /* $hook can be: a function, an object, an array of $function and $data,
  60                          * an array of just a function, an array of object and method, or an
  61                          * array of object, method, and data.
  62                          */
  63
  64                         if (is_array($hook)) {
  65                                 if (count($hook) < 1) {
  66                                         wfDieDebugBacktrace("Empty array in hooks for " . $event . "\n");
  67                                 } else if (is_object($hook[0])) {
  68                                         $object = $hook[0];
  69                                         if (count($hook) < 2) {
  70                                                 $method = "on" . $event;
  71                                         } else {
  72                                                 $method = $hook[1];
  73                                                 if (count($hook) > 2) {
  74                                                         $data = $hook[2];
  75                                                         $have_data = true;
  76                                                 }
  77                                         }
  78                                 } else if (is_string($hook[0])) {
  79                                         $func = $hook[0];
  80                                         if (count($hook) > 1) {
  81                                                 $data = $hook[1];
  82                                                 $have_data = true;
  83                                         }
  84                                 } else {
  85                                         wfDieDebugBacktrace("Unknown datatype in hooks for " . $event . "\n");
  86                                 }
  87                         } else if (is_string($hook)) { # functions look like strings, too
  88                                 $func = $hook;
  89                         } else if (is_object($hook)) {
  90                                 $object = $hook;
  91                                 $method = "on" . $event;
  92                         } else {
  93                                 wfDieDebugBacktrace("Unknown datatype in hooks for " . $event . "\n");
  94                         }
  95
  96                         /* We put the first data element on, if needed. */
  97
  98                         if ($have_data) {
  99                                 $hook_args = array_merge(array($data), $args);
 100                         } else {
 101                                 $hook_args = $args;
 102                         }
 103
 104                         /* Call the hook. */
 105
 106                         if ($object) {
 107                                 $retval = call_user_func_array(array($object, $method), $hook_args);
 108                         } else {
 109                                 $retval = call_user_func_array($func, $hook_args);
 110                         }
 111
 112                         /* String return is an error; false return means stop processing. */
 113
 114                         if (is_string($retval)) {
 115                                 global $wgOut;
 116                                 $wgOut->fatalError($retval);
 117                                 return false;
 118                         } else if (!$retval) {
 119                                 return false;
 120                         }
 121                 }
 122
 123                 return true;
 124         }
 125 } /* if defined(MEDIAWIKI) */
 126 ?>