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 use Wikimedia\Rdbms\ResultWrapper;
  25
  26 /**
  27  * A special page listing redirects to redirecting page.
  28  * The software will automatically not follow double redirects, to prevent loops.
  29  *
  30  * @ingroup SpecialPage
  31  */
  32 class DoubleRedirectsPage extends QueryPage {
  33         function __construct( $name = 'DoubleRedirects' ) {
  34                 parent::__construct( $name );
  35         }
  36
  37         public function isExpensive() {
  38                 return true;
  39         }
  40
  41         function isSyndicated() {
  42                 return false;
  43         }
  44
  45         function sortDescending() {
  46                 return false;
  47         }
  48
  49         function getPageHeader() {
  50                 return $this->msg( 'doubleredirectstext' )->parseAsBlock();
  51         }
  52
  53         function reallyGetQueryInfo( $namespace = null, $title = null ) {
  54                 $limitToTitle = !( $namespace === null && $title === null );
  55                 $dbr = wfGetDB( DB_REPLICA );
  56                 $retval = [
  57                         'tables' => [
  58                                 'ra' => 'redirect',
  59                                 'rb' => 'redirect',
  60                                 'pa' => 'page',
  61                                 'pb' => 'page'
  62                         ],
  63                         'fields' => [
  64                                 'namespace' => 'pa.page_namespace',
  65                                 'title' => 'pa.page_title',
  66                                 'value' => 'pa.page_title',
  67
  68                                 'nsb' => 'pb.page_namespace',
  69                                 'tb' => 'pb.page_title',
  70
  71                                 // Select fields from redirect instead of page. Because there may
  72                                 // not actually be a page table row for this target (e.g. for interwiki redirects)
  73                                 'nsc' => 'rb.rd_namespace',
  74                                 'tc' => 'rb.rd_title',
  75                                 'iwc' => 'rb.rd_interwiki',
  76                         ],
  77                         'conds' => [
  78                                 'ra.rd_from = pa.page_id',
  79
  80                                 // Filter out redirects where the target goes interwiki (T42353).
  81                                 // This isn't an optimization, it is required for correct results,
  82                                 // otherwise a non-double redirect like Bar -> w:Foo will show up
  83                                 // like "Bar -> Foo -> w:Foo".
  84
  85                                 // Need to check both NULL and "" for some reason,
  86                                 // apparently either can be stored for non-iw entries.
  87                                 'ra.rd_interwiki IS NULL OR ra.rd_interwiki = ' . $dbr->addQuotes( '' ),
  88
  89                                 'pb.page_namespace = ra.rd_namespace',
  90                                 'pb.page_title = ra.rd_title',
  91
  92                                 'rb.rd_from = pb.page_id',
  93                         ]
  94                 ];
  95
  96                 if ( $limitToTitle ) {
  97                         $retval['conds']['pa.page_namespace'] = $namespace;
  98                         $retval['conds']['pa.page_title'] = $title;
  99                 }
 100
 101                 return $retval;
 102         }
 103
 104         public function getQueryInfo() {
 105                 return $this->reallyGetQueryInfo();
 106         }
 107
 108         function getOrderFields() {
 109                 return [ 'ra.rd_namespace', 'ra.rd_title' ];
 110         }
 111
 112         /**
 113          * @param Skin $skin
 114          * @param object $result Result row
 115          * @return string
 116          */
 117         function formatResult( $skin, $result ) {
 118                 $titleA = Title::makeTitle( $result->namespace, $result->title );
 119
 120                 // If only titleA is in the query, it means this came from
 121                 // querycache (which only saves 3 columns).
 122                 // That does save the bulk of the query cost, but now we need to
 123                 // get a little more detail about each individual entry quickly
 124                 // using the filter of reallyGetQueryInfo.
 125                 if ( $result && !isset( $result->nsb ) ) {
 126                         $dbr = wfGetDB( DB_REPLICA );
 127                         $qi = $this->reallyGetQueryInfo(
 128                                 $result->namespace,
 129                                 $result->title
 130                         );
 131                         $res = $dbr->select(
 132                                 $qi['tables'],
 133                                 $qi['fields'],
 134                                 $qi['conds'],
 135                                 __METHOD__
 136                         );
 137
 138                         if ( $res ) {
 139                                 $result = $dbr->fetchObject( $res );
 140                         }
 141                 }
 142                 $linkRenderer = $this->getLinkRenderer();
 143                 if ( !$result ) {
 144                         return '<del>' . $linkRenderer->makeLink( $titleA, null, [], [ 'redirect' => 'no' ] ) . '</del>';
 145                 }
 146
 147                 $titleB = Title::makeTitle( $result->nsb, $result->tb );
 148                 $titleC = Title::makeTitle( $result->nsc, $result->tc, '', $result->iwc );
 149
 150                 $linkA = $linkRenderer->makeKnownLink(
 151                         $titleA,
 152                         null,
 153                         [],
 154                         [ 'redirect' => 'no' ]
 155                 );
 156
 157                 // if the page is editable, add an edit link
 158                 if (
 159                         // check user permissions
 160                         $this->getUser()->isAllowed( 'edit' ) &&
 161                         // check, if the content model is editable through action=edit
 162                         ContentHandler::getForTitle( $titleA )->supportsDirectEditing()
 163                 ) {
 164                         $edit = $linkRenderer->makeKnownLink(
 165                                 $titleA,
 166                                 $this->msg( 'parentheses', $this->msg( 'editlink' )->text() )->text(),
 167                                 [],
 168                                 [ 'action' => 'edit' ]
 169                         );
 170                 } else {
 171                         $edit = '';
 172                 }
 173
 174                 $linkB = $linkRenderer->makeKnownLink(
 175                         $titleB,
 176                         null,
 177                         [],
 178                         [ 'redirect' => 'no' ]
 179                 );
 180
 181                 $linkC = $linkRenderer->makeKnownLink( $titleC );
 182
 183                 $lang = $this->getLanguage();
 184                 $arr = $lang->getArrow() . $lang->getDirMark();
 185
 186                 return ( "{$linkA} {$edit} {$arr} {$linkB} {$arr} {$linkC}" );
 187         }
 188
 189         /**
 190          * Cache page content model and gender distinction for performance
 191          *
 192          * @param IDatabase $db
 193          * @param ResultWrapper $res
 194          */
 195         function preprocessResults( $db, $res ) {
 196                 if ( !$res->numRows() ) {
 197                         return;
 198                 }
 199
 200                 $batch = new LinkBatch;
 201                 foreach ( $res as $row ) {
 202                         $batch->add( $row->namespace, $row->title );
 203                         if ( isset( $row->nsb ) ) {
 204                                 // lazy loaded when using cached results
 205                                 $batch->add( $row->nsb, $row->tb );
 206                         }
 207                         if ( isset( $row->iwc ) && !$row->iwc ) {
 208                                 // lazy loaded when using cached result, not added when interwiki link
 209                                 $batch->add( $row->nsc, $row->tc );
 210                         }
 211                 }
 212                 $batch->execute();
 213
 214                 // Back to start for display
 215                 $res->seek( 0 );
 216         }
 217
 218         protected function getGroupName() {
 219                 return 'maintenance';
 220         }
 221 }