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 = null) {
  34
  35                 global $wgHooks;
  36                 $fname = 'wfRunHooks';
  37                 wfProfileIn( $fname );
  38
  39                 if (!is_array($wgHooks)) {
  40                         wfDieDebugBacktrace("Global hooks array is not an array!\n");
  41                         wfProfileOut( $fname );
  42                         return false;
  43                 }
  44
  45                 if (!array_key_exists($event, $wgHooks)) {
  46                         wfProfileOut( $fname );
  47                         return true;
  48                 }
  49
  50                 if (!is_array($wgHooks[$event])) {
  51                         wfDieDebugBacktrace("Hooks array for event '$event' is not an array!\n");
  52                         wfProfileOut( $fname );
  53                         return false;
  54                 }
  55
  56                 foreach ($wgHooks[$event] as $hook) {
  57
  58                         $object = NULL;
  59                         $method = NULL;
  60                         $func = NULL;
  61                         $data = NULL;
  62                         $have_data = false;
  63
  64                         /* $hook can be: a function, an object, an array of $function and $data,
  65                          * an array of just a function, an array of object and method, or an
  66                          * array of object, method, and data.
  67                          */
  68
  69                         if (is_array($hook)) {
  70                                 if (count($hook) < 1) {
  71                                         wfDieDebugBacktrace("Empty array in hooks for " . $event . "\n");
  72                                 } else if (is_object($hook[0])) {
  73                                         $object = $hook[0];
  74                                         if (count($hook) < 2) {
  75                                                 $method = "on" . $event;
  76                                         } else {
  77                                                 $method = $hook[1];
  78                                                 if (count($hook) > 2) {
  79                                                         $data = $hook[2];
  80                                                         $have_data = true;
  81                                                 }
  82                                         }
  83                                 } else if (is_string($hook[0])) {
  84                                         $func = $hook[0];
  85                                         if (count($hook) > 1) {
  86                                                 $data = $hook[1];
  87                                                 $have_data = true;
  88                                         }
  89                                 } else {
  90                                         wfDieDebugBacktrace("Unknown datatype in hooks for " . $event . "\n");
  91                                 }
  92                         } else if (is_string($hook)) { # functions look like strings, too
  93                                 $func = $hook;
  94                         } else if (is_object($hook)) {
  95                                 $object = $hook;
  96                                 $method = "on" . $event;
  97                         } else {
  98                                 wfDieDebugBacktrace("Unknown datatype in hooks for " . $event . "\n");
  99                         }
 100
 101                         /* We put the first data element on, if needed. */
 102
 103                         if ($have_data) {
 104                                 $hook_args = array_merge(array($data), $args);
 105                         } else {
 106                                 $hook_args = $args;
 107                         }
 108
 109
 110                         if ( $object ) {
 111                                 $func = get_class( $object ) . '::' . $method;
 112                         }
 113
 114                         /* Call the hook. */
 115                         wfProfileIn( $func );
 116                         if ($object) {
 117                                 $retval = call_user_func_array(array($object, $method), $hook_args);
 118                         } else {
 119                                 $retval = call_user_func_array($func, $hook_args);
 120                         }
 121                         wfProfileOut( $func );
 122
 123                         /* String return is an error; false return means stop processing. */
 124
 125                         if (is_string($retval)) {
 126                                 global $wgOut;
 127                                 $wgOut->fatalError($retval);
 128                                 wfProfileOut( $fname );
 129                                 return false;
 130                         } else if (!$retval) {
 131                                 wfProfileOut( $fname );
 132                                 return false;
 133                         }
 134                 }
 135
 136                 wfProfileOut( $fname );
 137                 return true;
 138         }
 139 } /* if defined(MEDIAWIKI) */
 140 ?>