includes/specials/SpecialDoubleRedirects.php

   1 <?php
   2 /**
   3  * Implements Special:DoubleRedirects
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup SpecialPage
  22  */
  23
  24 /**
  25  * A special page listing redirects to redirecting page.
  26  * The software will automatically not follow double redirects, to prevent loops.
  27  *
  28  * @ingroup SpecialPage
  29  */
  30 class DoubleRedirectsPage extends QueryPage {
  31         function __construct( $name = 'DoubleRedirects' ) {
  32                 parent::__construct( $name );
  33         }
  34
  35         function isExpensive() {
  36                 return true;
  37         }
  38
  39         function isSyndicated() {
  40                 return false;
  41         }
  42
  43         function sortDescending() {
  44                 return false;
  45         }
  46
  47         function getPageHeader() {
  48                 return $this->msg( 'doubleredirectstext' )->parseAsBlock();
  49         }
  50
  51         function reallyGetQueryInfo( $namespace = null, $title = null ) {
  52                 $limitToTitle = !( $namespace === null && $title === null );
  53                 $dbr = wfGetDB( DB_SLAVE );
  54                 $retval = array(
  55                         'tables' => array(
  56                                 'ra' => 'redirect',
  57                                 'rb' => 'redirect',
  58                                 'pa' => 'page',
  59                                 'pb' => 'page'
  60                         ),
  61                         'fields' => array(
  62                                 'namespace' => 'pa.page_namespace',
  63                                 'title' => 'pa.page_title',
  64                                 'value' => 'pa.page_title',
  65
  66                                 'nsb' => 'pb.page_namespace',
  67                                 'tb' => 'pb.page_title',
  68
  69                                 // Select fields from redirect instead of page. Because there may
  70                                 // not actually be a page table row for this target (e.g. for interwiki redirects)
  71                                 'nsc' => 'rb.rd_namespace',
  72                                 'tc' => 'rb.rd_title',
  73                                 'iwc' => 'rb.rd_interwiki',
  74                         ),
  75                         'conds' => array(
  76                                 'ra.rd_from = pa.page_id',
  77
  78                                 // Filter out redirects where the target goes interwiki (bug 40353).
  79                                 // This isn't an optimization, it is required for correct results,
  80                                 // otherwise a non-double redirect like Bar -> w:Foo will show up
  81                                 // like "Bar -> Foo -> w:Foo".
  82
  83                                 // Need to check both NULL and "" for some reason,
  84                                 // apparently either can be stored for non-iw entries.
  85                                 'ra.rd_interwiki IS NULL OR ra.rd_interwiki = ' . $dbr->addQuotes( '' ),
  86
  87                                 'pb.page_namespace = ra.rd_namespace',
  88                                 'pb.page_title = ra.rd_title',
  89
  90                                 'rb.rd_from = pb.page_id',
  91                         )
  92                 );
  93
  94                 if ( $limitToTitle ) {
  95                         $retval['conds']['pa.page_namespace'] = $namespace;
  96                         $retval['conds']['pa.page_title'] = $title;
  97                 }
  98
  99                 return $retval;
 100         }
 101
 102         function getQueryInfo() {
 103                 return $this->reallyGetQueryInfo();
 104         }
 105
 106         function getOrderFields() {
 107                 return array( 'ra.rd_namespace', 'ra.rd_title' );
 108         }
 109
 110         /**
 111          * @param Skin $skin
 112          * @param object $result Result row
 113          * @return string
 114          */
 115         function formatResult( $skin, $result ) {
 116                 $titleA = Title::makeTitle( $result->namespace, $result->title );
 117
 118                 // If only titleA is in the query, it means this came from
 119                 // querycache (which only saves 3 columns).
 120                 // That does save the bulk of the query cost, but now we need to
 121                 // get a little more detail about each individual entry quickly
 122                 // using the filter of reallyGetQueryInfo.
 123                 if ( $result && !isset( $result->nsb ) ) {
 124                         $dbr = wfGetDB( DB_SLAVE );
 125                         $qi = $this->reallyGetQueryInfo(
 126                                 $result->namespace,
 127                                 $result->title
 128                         );
 129                         $res = $dbr->select(
 130                                 $qi['tables'],
 131                                 $qi['fields'],
 132                                 $qi['conds'],
 133                                 __METHOD__
 134                         );
 135
 136                         if ( $res ) {
 137                                 $result = $dbr->fetchObject( $res );
 138                         }
 139                 }
 140                 if ( !$result ) {
 141                         return '<del>' . Linker::link( $titleA, null, array(), array( 'redirect' => 'no' ) ) . '</del>';
 142                 }
 143
 144                 $titleB = Title::makeTitle( $result->nsb, $result->tb );
 145                 $titleC = Title::makeTitle( $result->nsc, $result->tc, '', $result->iwc );
 146
 147                 $linkA = Linker::linkKnown(
 148                         $titleA,
 149                         null,
 150                         array(),
 151                         array( 'redirect' => 'no' )
 152                 );
 153
 154                 $edit = Linker::linkKnown(
 155                         $titleA,
 156                         $this->msg( 'parentheses', $this->msg( 'editlink' )->text() )->escaped(),
 157                         array(),
 158                         array(
 159                                 'redirect' => 'no',
 160                                 'action' => 'edit'
 161                         )
 162                 );
 163
 164                 $linkB = Linker::linkKnown(
 165                         $titleB,
 166                         null,
 167                         array(),
 168                         array( 'redirect' => 'no' )
 169                 );
 170
 171                 $linkC = Linker::linkKnown( $titleC );
 172
 173                 $lang = $this->getLanguage();
 174                 $arr = $lang->getArrow() . $lang->getDirMark();
 175
 176                 return ( "{$linkA} {$edit} {$arr} {$linkB} {$arr} {$linkC}" );
 177         }
 178
 179         protected function getGroupName() {
 180                 return 'maintenance';
 181         }
 182 }