includes/api/ApiQueryLangLinks.php

   1 <?php
   2 /**
   3  *
   4  *
   5  * Created on May 13, 2007
   6  *
   7  * Copyright © 2006 Yuri Astrakhan "<Firstname><Lastname>@gmail.com"
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write to the Free Software Foundation, Inc.,
  21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  22  * http://www.gnu.org/copyleft/gpl.html
  23  *
  24  * @file
  25  */
  26
  27 /**
  28  * A query module to list all langlinks (links to corresponding foreign language pages).
  29  *
  30  * @ingroup API
  31  */
  32 class ApiQueryLangLinks extends ApiQueryBase {
  33
  34         public function __construct( $query, $moduleName ) {
  35                 parent::__construct( $query, $moduleName, 'll' );
  36         }
  37
  38         public function execute() {
  39                 if ( $this->getPageSet()->getGoodTitleCount() == 0 ) {
  40                         return;
  41                 }
  42
  43                 $params = $this->extractRequestParams();
  44
  45                 if ( isset( $params['title'] ) && !isset( $params['lang'] ) ) {
  46                         $this->dieUsageMsg( array( 'missingparam', 'lang' ) );
  47                 }
  48
  49                 $this->addFields( array(
  50                         'll_from',
  51                         'll_lang',
  52                         'll_title'
  53                 ) );
  54
  55                 $this->addTables( 'langlinks' );
  56                 $this->addWhereFld( 'll_from', array_keys( $this->getPageSet()->getGoodTitles() ) );
  57                 if ( !is_null( $params['continue'] ) ) {
  58                         $cont = explode( '|', $params['continue'] );
  59                         $this->dieContinueUsageIf( count( $cont ) != 2 );
  60                         $op = $params['dir'] == 'descending' ? '<' : '>';
  61                         $llfrom = intval( $cont[0] );
  62                         $lllang = $this->getDB()->addQuotes( $cont[1] );
  63                         $this->addWhere(
  64                                 "ll_from $op $llfrom OR " .
  65                                 "(ll_from = $llfrom AND " .
  66                                 "ll_lang $op= $lllang)"
  67                         );
  68                 }
  69
  70                 //FIXME: (follow-up) To allow extensions to add to the language links, we need
  71                 //       to load them all, add the extra links, then apply paging.
  72                 //       Should not be terrible, it's not going to be more than a few hundred links.
  73
  74                 // Note that, since (ll_from, ll_lang) is a unique key, we don't need
  75                 // to sort by ll_title to ensure deterministic ordering.
  76                 $sort = ( $params['dir'] == 'descending' ? ' DESC' : '' );
  77                 if ( isset( $params['lang'] ) ) {
  78                         $this->addWhereFld( 'll_lang', $params['lang'] );
  79                         if ( isset( $params['title'] ) ) {
  80                                 $this->addWhereFld( 'll_title', $params['title'] );
  81                         }
  82                         $this->addOption( 'ORDER BY', 'll_from' . $sort );
  83                 } else {
  84                         // Don't order by ll_from if it's constant in the WHERE clause
  85                         if ( count( $this->getPageSet()->getGoodTitles() ) == 1 ) {
  86                                 $this->addOption( 'ORDER BY', 'll_lang' . $sort );
  87                         } else {
  88                                 $this->addOption( 'ORDER BY', array(
  89                                                         'll_from' . $sort,
  90                                                         'll_lang' . $sort
  91                                 ));
  92                         }
  93                 }
  94
  95                 $this->addOption( 'LIMIT', $params['limit'] + 1 );
  96                 $res = $this->select( __METHOD__ );
  97
  98                 $count = 0;
  99                 foreach ( $res as $row ) {
 100                         if ( ++$count > $params['limit'] ) {
 101                                 // We've reached the one extra which shows that
 102                                 // there are additional pages to be had. Stop here...
 103                                 $this->setContinueEnumParameter( 'continue', "{$row->ll_from}|{$row->ll_lang}" );
 104                                 break;
 105                         }
 106                         $entry = array( 'lang' => $row->ll_lang );
 107                         if ( $params['url'] ) {
 108                                 $title = Title::newFromText( "{$row->ll_lang}:{$row->ll_title}" );
 109                                 if ( $title ) {
 110                                         $entry['url'] = wfExpandUrl( $title->getFullURL(), PROTO_CURRENT );
 111                                 }
 112                         }
 113                         ApiResult::setContent( $entry, $row->ll_title );
 114                         $fit = $this->addPageSubItem( $row->ll_from, $entry );
 115                         if ( !$fit ) {
 116                                 $this->setContinueEnumParameter( 'continue', "{$row->ll_from}|{$row->ll_lang}" );
 117                                 break;
 118                         }
 119                 }
 120         }
 121
 122         public function getCacheMode( $params ) {
 123                 return 'public';
 124         }
 125
 126         public function getAllowedParams() {
 127                 return array(
 128                         'limit' => array(
 129                                 ApiBase::PARAM_DFLT => 10,
 130                                 ApiBase::PARAM_TYPE => 'limit',
 131                                 ApiBase::PARAM_MIN => 1,
 132                                 ApiBase::PARAM_MAX => ApiBase::LIMIT_BIG1,
 133                                 ApiBase::PARAM_MAX2 => ApiBase::LIMIT_BIG2
 134                         ),
 135                         'continue' => null,
 136                         'url' => false,
 137                         'lang' => null,
 138                         'title' => null,
 139                         'dir' => array(
 140                                 ApiBase::PARAM_DFLT => 'ascending',
 141                                 ApiBase::PARAM_TYPE => array(
 142                                         'ascending',
 143                                         'descending'
 144                                 )
 145                         ),
 146                 );
 147         }
 148
 149         public function getParamDescription() {
 150                 return array(
 151                         'limit' => 'How many langlinks to return',
 152                         'continue' => 'When more results are available, use this to continue',
 153                         'url' => 'Whether to get the full URL',
 154                         'lang' => 'Language code',
 155                         'title' => "Link to search for. Must be used with {$this->getModulePrefix()}lang",
 156                         'dir' => 'The direction in which to list',
 157                 );
 158         }
 159
 160         public function getResultProperties() {
 161                 return array(
 162                         '' => array(
 163                                 'lang' => 'string',
 164                                 'url' => array(
 165                                         ApiBase::PROP_TYPE => 'string',
 166                                         ApiBase::PROP_NULLABLE => true
 167                                 ),
 168                                 '*' => 'string'
 169                         )
 170                 );
 171         }
 172
 173         public function getDescription() {
 174                 return 'Returns all interlanguage links from the given page(s)';
 175         }
 176
 177         public function getPossibleErrors() {
 178                 return array_merge( parent::getPossibleErrors(), array(
 179                         array( 'missingparam', 'lang' ),
 180                 ) );
 181         }
 182
 183         public function getExamples() {
 184                 return array(
 185                         'api.php?action=query&prop=langlinks&titles=Main%20Page&redirects=' => 'Get interlanguage links from the [[Main Page]]',
 186                 );
 187         }
 188
 189         public function getHelpUrls() {
 190                 return 'https://www.mediawiki.org/wiki/API:Properties#langlinks_.2F_ll';
 191         }
 192 }