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 MediaWiki\MediaWikiServices;
  25 use Wikimedia\Rdbms\IResultWrapper;
  26 use Wikimedia\Rdbms\IDatabase;
  27
  28 /**
  29  * A special page listing redirects to redirecting page.
  30  * The software will automatically not follow double redirects, to prevent loops.
  31  *
  32  * @ingroup SpecialPage
  33  */
  34 class SpecialDoubleRedirects extends QueryPage {
  35         function __construct( $name = 'DoubleRedirects' ) {
  36                 parent::__construct( $name );
  37         }
  38
  39         public function isExpensive() {
  40                 return true;
  41         }
  42
  43         function isSyndicated() {
  44                 return false;
  45         }
  46
  47         function sortDescending() {
  48                 return false;
  49         }
  50
  51         function getPageHeader() {
  52                 return $this->msg( 'doubleredirectstext' )->parseAsBlock();
  53         }
  54
  55         function reallyGetQueryInfo( $namespace = null, $title = null ) {
  56                 $limitToTitle = !( $namespace === null && $title === null );
  57                 $dbr = wfGetDB( DB_REPLICA );
  58                 $retval = [
  59                         'tables' => [
  60                                 'ra' => 'redirect',
  61                                 'rb' => 'redirect',
  62                                 'pa' => 'page',
  63                                 'pb' => 'page'
  64                         ],
  65                         'fields' => [
  66                                 'namespace' => 'pa.page_namespace',
  67                                 'title' => 'pa.page_title',
  68                                 'value' => 'pa.page_title',
  69
  70                                 'b_namespace' => 'pb.page_namespace',
  71                                 'b_title' => 'pb.page_title',
  72
  73                                 // Select fields from redirect instead of page. Because there may
  74                                 // not actually be a page table row for this target (e.g. for interwiki redirects)
  75                                 'c_namespace' => 'rb.rd_namespace',
  76                                 'c_title' => 'rb.rd_title',
  77                                 'c_fragment' => 'rb.rd_fragment',
  78                                 'c_interwiki' => 'rb.rd_interwiki',
  79                         ],
  80                         'conds' => [
  81                                 'ra.rd_from = pa.page_id',
  82
  83                                 // Filter out redirects where the target goes interwiki (T42353).
  84                                 // This isn't an optimization, it is required for correct results,
  85                                 // otherwise a non-double redirect like Bar -> w:Foo will show up
  86                                 // like "Bar -> Foo -> w:Foo".
  87
  88                                 // Need to check both NULL and "" for some reason,
  89                                 // apparently either can be stored for non-iw entries.
  90                                 'ra.rd_interwiki IS NULL OR ra.rd_interwiki = ' . $dbr->addQuotes( '' ),
  91
  92                                 'pb.page_namespace = ra.rd_namespace',
  93                                 'pb.page_title = ra.rd_title',
  94
  95                                 'rb.rd_from = pb.page_id',
  96                         ]
  97                 ];
  98
  99                 if ( $limitToTitle ) {
 100                         $retval['conds']['pa.page_namespace'] = $namespace;
 101                         $retval['conds']['pa.page_title'] = $title;
 102                 }
 103
 104                 return $retval;
 105         }
 106
 107         public function getQueryInfo() {
 108                 return $this->reallyGetQueryInfo();
 109         }
 110
 111         function getOrderFields() {
 112                 return [ 'ra.rd_namespace', 'ra.rd_title' ];
 113         }
 114
 115         /**
 116          * @param Skin $skin
 117          * @param object $result Result row
 118          * @return string
 119          */
 120         function formatResult( $skin, $result ) {
 121                 // If no Title B or C is in the query, it means this came from
 122                 // querycache (which only saves the 3 columns for title A).
 123                 // That does save the bulk of the query cost, but now we need to
 124                 // get a little more detail about each individual entry quickly
 125                 // using the filter of reallyGetQueryInfo.
 126                 $deep = false;
 127                 if ( $result ) {
 128                         if ( isset( $result->b_namespace ) ) {
 129                                 $deep = $result;
 130                         } else {
 131                                 $dbr = wfGetDB( DB_REPLICA );
 132                                 $qi = $this->reallyGetQueryInfo(
 133                                         $result->namespace,
 134                                         $result->title
 135                                 );
 136                                 $res = $dbr->select(
 137                                         $qi['tables'],
 138                                         $qi['fields'],
 139                                         $qi['conds'],
 140                                         __METHOD__
 141                                 );
 142
 143                                 if ( $res ) {
 144                                         $deep = $dbr->fetchObject( $res ) ?: false;
 145                                 }
 146                         }
 147                 }
 148
 149                 $titleA = Title::makeTitle( $result->namespace, $result->title );
 150
 151                 $linkRenderer = $this->getLinkRenderer();
 152                 if ( !$deep ) {
 153                         return '<del>' . $linkRenderer->makeLink( $titleA, null, [], [ 'redirect' => 'no' ] ) . '</del>';
 154                 }
 155
 156                 // if the page is editable, add an edit link
 157                 if (
 158                         // check user permissions
 159                         MediaWikiServices::getInstance()
 160                                 ->getPermissionManager()
 161                                 ->userHasRight( $this->getUser(), 'edit' ) &&
 162                         // check, if the content model is editable through action=edit
 163                         ContentHandler::getForTitle( $titleA )->supportsDirectEditing()
 164                 ) {
 165                         $edit = $linkRenderer->makeKnownLink(
 166                                 $titleA,
 167                                 $this->msg( 'parentheses', $this->msg( 'editlink' )->text() )->text(),
 168                                 [],
 169                                 [ 'action' => 'edit' ]
 170                         );
 171                 } else {
 172                         $edit = '';
 173                 }
 174
 175                 $linkA = $linkRenderer->makeKnownLink(
 176                         $titleA,
 177                         null,
 178                         [],
 179                         [ 'redirect' => 'no' ]
 180                 );
 181
 182                 $titleB = Title::makeTitle( $deep->b_namespace, $deep->b_title );
 183                 $linkB = $linkRenderer->makeKnownLink(
 184                         $titleB,
 185                         null,
 186                         [],
 187                         [ 'redirect' => 'no' ]
 188                 );
 189
 190                 $titleC = Title::makeTitle(
 191                         $deep->c_namespace,
 192                         $deep->c_title,
 193                         $deep->c_fragment,
 194                         $deep->c_interwiki
 195                 );
 196                 $linkC = $linkRenderer->makeKnownLink( $titleC, $titleC->getFullText() );
 197
 198                 $lang = $this->getLanguage();
 199                 $arr = $lang->getArrow() . $lang->getDirMark();
 200
 201                 return ( "{$linkA} {$edit} {$arr} {$linkB} {$arr} {$linkC}" );
 202         }
 203
 204         public function execute( $par ) {
 205                 $this->addHelpLink( 'Help:Redirects' );
 206                 parent::execute( $par );
 207         }
 208
 209         /**
 210          * Cache page content model and gender distinction for performance
 211          *
 212          * @param IDatabase $db
 213          * @param IResultWrapper $res
 214          */
 215         function preprocessResults( $db, $res ) {
 216                 if ( !$res->numRows() ) {
 217                         return;
 218                 }
 219
 220                 $batch = new LinkBatch;
 221                 foreach ( $res as $row ) {
 222                         $batch->add( $row->namespace, $row->title );
 223                         if ( isset( $row->b_namespace ) ) {
 224                                 // lazy loaded when using cached results
 225                                 $batch->add( $row->b_namespace, $row->b_title );
 226                         }
 227                         if ( isset( $row->c_interwiki ) && !$row->c_interwiki ) {
 228                                 // lazy loaded when using cached result, not added when interwiki link
 229                                 $batch->add( $row->c_namespace, $row->c_title );
 230                         }
 231                 }
 232                 $batch->execute();
 233
 234                 // Back to start for display
 235                 $res->seek( 0 );
 236         }
 237
 238         protected function getGroupName() {
 239                 return 'maintenance';
 240         }
 241 }