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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * @author Evan Prodromou <evan@wikitravel.org>
  21  * @see hooks.txt
  22  */
  23
  24
  25 /**
  26  * Because programmers assign to $wgHooks, we need to be very
  27  * careful about its contents. So, there's a lot more error-checking
  28  * in here than would normally be necessary.
  29  */
  30 function wfRunHooks($event, $args = null) {
  31
  32         global $wgHooks;
  33
  34         if (!is_array($wgHooks)) {
  35                 throw new MWException("Global hooks array is not an array!\n");
  36                 return false;
  37         }
  38
  39         if (!array_key_exists($event, $wgHooks)) {
  40                 return true;
  41         }
  42
  43         if (!is_array($wgHooks[$event])) {
  44                 throw new MWException("Hooks array for event '$event' is not an array!\n");
  45                 return false;
  46         }
  47
  48         foreach ($wgHooks[$event] as $index => $hook) {
  49
  50                 $object = NULL;
  51                 $method = NULL;
  52                 $func = NULL;
  53                 $data = NULL;
  54                 $have_data = false;
  55
  56                 /* $hook can be: a function, an object, an array of $function and $data,
  57                  * an array of just a function, an array of object and method, or an
  58                  * array of object, method, and data.
  59                  */
  60
  61                 if (is_array($hook)) {
  62                         if (count($hook) < 1) {
  63                                 throw new MWException("Empty array in hooks for " . $event . "\n");
  64                         } else if (is_object($hook[0])) {
  65                                 $object = $wgHooks[$event][$index][0];
  66                                 if (count($hook) < 2) {
  67                                         $method = "on" . $event;
  68                                 } else {
  69                                         $method = $hook[1];
  70                                         if (count($hook) > 2) {
  71                                                 $data = $hook[2];
  72                                                 $have_data = true;
  73                                         }
  74                                 }
  75                         } else if (is_string($hook[0])) {
  76                                 $func = $hook[0];
  77                                 if (count($hook) > 1) {
  78                                         $data = $hook[1];
  79                                         $have_data = true;
  80                                 }
  81                         } else {
  82                                 var_dump( $wgHooks );
  83                                 throw new MWException("Unknown datatype in hooks for " . $event . "\n");
  84                         }
  85                 } else if (is_string($hook)) { # functions look like strings, too
  86                         $func = $hook;
  87                 } else if (is_object($hook)) {
  88                         $object = $wgHooks[$event][$index];
  89                         $method = "on" . $event;
  90                 } else {
  91                         throw new MWException("Unknown datatype in hooks for " . $event . "\n");
  92                 }
  93
  94                 /* We put the first data element on, if needed. */
  95
  96                 if ($have_data) {
  97                         $hook_args = array_merge(array($data), $args);
  98                 } else {
  99                         $hook_args = $args;
 100                 }
 101
 102                 if ( isset( $object ) ) {
 103                         $func = get_class( $object ) . '::' . $method;
 104                         $callback = array( $object, $method );
 105                 } elseif ( false !== ( $pos = strpos( $func, '::' ) ) ) {
 106                         $callback = array( substr( $func, 0, $pos ), substr( $func, $pos + 2 ) );
 107                 } else {
 108                         $callback = $func;
 109                 }
 110
 111                 /* Call the hook. */
 112                 wfProfileIn( $func );
 113                 $retval = call_user_func_array( $callback, $hook_args );
 114                 wfProfileOut( $func );
 115
 116                 /* String return is an error; false return means stop processing. */
 117
 118                 if (is_string($retval)) {
 119                         global $wgOut;
 120                         $wgOut->showFatalError($retval);
 121                         return false;
 122                 } elseif( $retval === null ) {
 123                         if( is_array( $callback ) ) {
 124                                 if( is_object( $callback[0] ) ) {
 125                                         $prettyClass = get_class( $callback[0] );
 126                                 } else {
 127                                         $prettyClass = strval( $callback[1] );
 128                                 }
 129                                 $prettyFunc = $prettyClass . '::' . strval( $callback[1] );
 130                         } else {
 131                                 $prettyFunc = strval( $callback );
 132                         }
 133                         throw new MWException( "Invalid NULL return from broken hook $prettyFunc" );
 134                 } else if (!$retval) {
 135                         return false;
 136                 }
 137         }
 138
 139         return true;
 140 }
 141 ?>