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
  26 /**
  27  * Because programmers assign to $wgHooks, we need to be very
  28  * careful about its contents. So, there's a lot more error-checking
  29  * in here than would normally be necessary.
  30  */
  31 function wfRunHooks($event, $args = null) {
  32
  33         global $wgHooks;
  34         $fname = 'wfRunHooks';
  35         wfProfileIn( $fname );
  36
  37         if (!is_array($wgHooks)) {
  38                 wfDebugDieBacktrace("Global hooks array is not an array!\n");
  39                 wfProfileOut( $fname );
  40                 return false;
  41         }
  42
  43         if (!array_key_exists($event, $wgHooks)) {
  44                 wfProfileOut( $fname );
  45                 return true;
  46         }
  47
  48         if (!is_array($wgHooks[$event])) {
  49                 wfDebugDieBacktrace("Hooks array for event '$event' is not an array!\n");
  50                 wfProfileOut( $fname );
  51                 return false;
  52         }
  53
  54         foreach ($wgHooks[$event] as $index => $hook) {
  55
  56                 $object = NULL;
  57                 $method = NULL;
  58                 $func = NULL;
  59                 $data = NULL;
  60                 $have_data = false;
  61
  62                 /* $hook can be: a function, an object, an array of $function and $data,
  63                  * an array of just a function, an array of object and method, or an
  64                  * array of object, method, and data.
  65                  */
  66
  67                 if (is_array($hook)) {
  68                         if (count($hook) < 1) {
  69                                 wfDebugDieBacktrace("Empty array in hooks for " . $event . "\n");
  70                         } else if (is_object($hook[0])) {
  71                                 $object =& $wgHooks[$event][$index][0];
  72                                 if (count($hook) < 2) {
  73                                         $method = "on" . $event;
  74                                 } else {
  75                                         $method = $hook[1];
  76                                         if (count($hook) > 2) {
  77                                                 $data = $hook[2];
  78                                                 $have_data = true;
  79                                         }
  80                                 }
  81                         } else if (is_string($hook[0])) {
  82                                 $func = $hook[0];
  83                                 if (count($hook) > 1) {
  84                                         $data = $hook[1];
  85                                         $have_data = true;
  86                                 }
  87                         } else {
  88                                 wfDebugDieBacktrace("Unknown datatype in hooks for " . $event . "\n");
  89                         }
  90                 } else if (is_string($hook)) { # functions look like strings, too
  91                         $func = $hook;
  92                 } else if (is_object($hook)) {
  93                         $object =& $wgHooks[$event][$index];
  94                         $method = "on" . $event;
  95                 } else {
  96                         wfDebugDieBacktrace("Unknown datatype in hooks for " . $event . "\n");
  97                 }
  98
  99                 /* We put the first data element on, if needed. */
 100
 101                 if ($have_data) {
 102                         $hook_args = array_merge(array($data), $args);
 103                 } else {
 104                         $hook_args = $args;
 105                 }
 106
 107
 108                 if ( isset( $object ) ) {
 109                         $func = get_class( $object ) . '::' . $method;
 110                 }
 111
 112                 /* Call the hook. */
 113                 wfProfileIn( $func );
 114                 if( isset( $object ) ) {
 115                         $retval = call_user_func_array(array(&$object, $method), $hook_args);
 116                 } else {
 117                         $retval = call_user_func_array($func, $hook_args);
 118                 }
 119                 wfProfileOut( $func );
 120
 121                 /* String return is an error; false return means stop processing. */
 122
 123                 if (is_string($retval)) {
 124                         global $wgOut;
 125                         $wgOut->fatalError($retval);
 126                         wfProfileOut( $fname );
 127                         return false;
 128                 } else if (!$retval) {
 129                         wfProfileOut( $fname );
 130                         return false;
 131                 }
 132         }
 133
 134         wfProfileOut( $fname );
 135         return true;
 136 }
 137 ?>