includes/ChangeTags.php

   1 <?php
   2 /**
   3  * Recent changes tagging.
   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  */
  22
  23 class ChangeTags {
  24
  25         /**
  26          * Creates HTML for the given tags
  27          *
  28          * @param $tags String: Comma-separated list of tags
  29          * @param $page String: A label for the type of action which is being displayed,
  30          *                     for example: 'history', 'contributions' or 'newpages'
  31          *
  32          * @return Array with two items: (html, classes)
  33          *            - html: String: HTML for displaying the tags (empty string when param $tags is empty)
  34          *            - classes: Array of strings: CSS classes used in the generated html, one class for each tag
  35          *
  36          */
  37         static function formatSummaryRow( $tags, $page ) {
  38                 global $wgLang;
  39
  40                 if( !$tags )
  41                         return array( '', array() );
  42
  43                 $classes = array();
  44
  45                 $tags = explode( ',', $tags );
  46                 $displayTags = array();
  47                 foreach( $tags as $tag ) {
  48                         $displayTags[] = Xml::tags(
  49                                 'span',
  50                                 array( 'class' => 'mw-tag-marker ' .
  51                                                                 Sanitizer::escapeClass( "mw-tag-marker-$tag" ) ),
  52                                 self::tagDescription( $tag )
  53                         );
  54                         $classes[] = Sanitizer::escapeClass( "mw-tag-$tag" );
  55                 }
  56                 $markers = wfMessage( 'parentheses' )->rawParams( $wgLang->commaList( $displayTags ) )->text();
  57                 $markers = Xml::tags( 'span', array( 'class' => 'mw-tag-markers' ), $markers );
  58
  59                 return array( $markers, $classes );
  60         }
  61
  62         /**
  63          * Get a short description for a tag
  64          *
  65          * @param $tag String: tag
  66          *
  67          * @return String: Short description of the tag from "mediawiki:tag-$tag" if this message exists,
  68          *                 html-escaped version of $tag otherwise
  69          */
  70         static function tagDescription( $tag ) {
  71                 $msg = wfMessage( "tag-$tag" );
  72                 return $msg->exists() ? $msg->parse() : htmlspecialchars( $tag );
  73         }
  74
  75         /**
  76          * Add tags to a change given its rc_id, rev_id and/or log_id
  77          *
  78          * @param $tags String|Array: Tags to add to the change
  79          * @param $rc_id int: rc_id of the change to add the tags to
  80          * @param $rev_id int: rev_id of the change to add the tags to
  81          * @param $log_id int: log_id of the change to add the tags to
  82          * @param $params String: params to put in the ct_params field of tabel 'change_tag'
  83          *
  84          * @return bool: false if no changes are made, otherwise true
  85          *
  86          * @exception MWException when $rc_id, $rev_id and $log_id are all null
  87          */
  88         static function addTags( $tags, $rc_id = null, $rev_id = null, $log_id = null, $params = null ) {
  89                 if ( !is_array( $tags ) ) {
  90                         $tags = array( $tags );
  91                 }
  92
  93                 $tags = array_filter( $tags ); // Make sure we're submitting all tags...
  94
  95                 if( !$rc_id && !$rev_id && !$log_id ) {
  96                         throw new MWException( "At least one of: RCID, revision ID, and log ID MUST be specified when adding a tag to a change!" );
  97                 }
  98
  99                 $dbr = wfGetDB( DB_SLAVE );
 100
 101                 // Might as well look for rcids and so on.
 102                 if( !$rc_id ) {
 103                         $dbr = wfGetDB( DB_MASTER ); // Info might be out of date, somewhat fractionally, on slave.
 104                         if( $log_id ) {
 105                                 $rc_id = $dbr->selectField( 'recentchanges', 'rc_id', array( 'rc_logid' => $log_id ), __METHOD__ );
 106                         } elseif( $rev_id ) {
 107                                 $rc_id = $dbr->selectField( 'recentchanges', 'rc_id', array( 'rc_this_oldid' => $rev_id ), __METHOD__ );
 108                         }
 109                 } elseif( !$log_id && !$rev_id ) {
 110                         $dbr = wfGetDB( DB_MASTER ); // Info might be out of date, somewhat fractionally, on slave.
 111                         $log_id = $dbr->selectField( 'recentchanges', 'rc_logid', array( 'rc_id' => $rc_id ), __METHOD__ );
 112                         $rev_id = $dbr->selectField( 'recentchanges', 'rc_this_oldid', array( 'rc_id' => $rc_id ), __METHOD__ );
 113                 }
 114
 115                 $tsConds = array_filter( array( 'ts_rc_id' => $rc_id, 'ts_rev_id' => $rev_id, 'ts_log_id' => $log_id ) );
 116
 117                 ## Update the summary row.
 118                 $prevTags = $dbr->selectField( 'tag_summary', 'ts_tags', $tsConds, __METHOD__ );
 119                 $prevTags = $prevTags ? $prevTags : '';
 120                 $prevTags = array_filter( explode( ',', $prevTags ) );
 121                 $newTags = array_unique( array_merge( $prevTags, $tags ) );
 122                 sort( $prevTags );
 123                 sort( $newTags );
 124
 125                 if ( $prevTags == $newTags ) {
 126                         // No change.
 127                         return false;
 128                 }
 129
 130                 $dbw = wfGetDB( DB_MASTER );
 131                 $dbw->replace(
 132                         'tag_summary',
 133                         array( 'ts_rev_id', 'ts_rc_id', 'ts_log_id' ),
 134                         array_filter( array_merge( $tsConds, array( 'ts_tags' => implode( ',', $newTags ) ) ) ),
 135                         __METHOD__
 136                 );
 137
 138                 // Insert the tags rows.
 139                 $tagsRows = array();
 140                 foreach( $tags as $tag ) { // Filter so we don't insert NULLs as zero accidentally.
 141                         $tagsRows[] = array_filter(
 142                                 array(
 143                                         'ct_tag' => $tag,
 144                                         'ct_rc_id' => $rc_id,
 145                                         'ct_log_id' => $log_id,
 146                                         'ct_rev_id' => $rev_id,
 147                                         'ct_params' => $params
 148                                 )
 149                         );
 150                 }
 151
 152                 $dbw->insert( 'change_tag', $tagsRows, __METHOD__, array( 'IGNORE' ) );
 153
 154                 return true;
 155         }
 156
 157         /**
 158          * Applies all tags-related changes to a query.
 159          * Handles selecting tags, and filtering.
 160          * Needs $tables to be set up properly, so we can figure out which join conditions to use.
 161          *
 162          * @param $tables String|Array: Tabel names, see DatabaseBase::select
 163          * @param $fields String|Array: Fields used in query, see DatabaseBase::select
 164          * @param $conds String|Array: conditions used in query, see DatabaseBase::select
 165          * @param $join_conds Array: join conditions, see DatabaseBase::select
 166          * @param $options Array: options, see Database::select
 167          * @param $filter_tag String: tag to select on
 168          *
 169          * @exception MWException when unable to determine appropriate JOIN condition for tagging
 170          *
 171          */
 172         static function modifyDisplayQuery( &$tables, &$fields,  &$conds,
 173                                                                                 &$join_conds, &$options, $filter_tag = false ) {
 174                 global $wgRequest, $wgUseTagFilter;
 175
 176                 if( $filter_tag === false ) {
 177                         $filter_tag = $wgRequest->getVal( 'tagfilter' );
 178                 }
 179
 180                 // Figure out which conditions can be done.
 181                 if ( in_array( 'recentchanges', $tables ) ) {
 182                         $join_cond = 'rc_id';
 183                 } elseif( in_array( 'logging', $tables ) ) {
 184                         $join_cond = 'log_id';
 185                 } elseif ( in_array( 'revision', $tables ) ) {
 186                         $join_cond = 'rev_id';
 187                 } else {
 188                         throw new MWException( 'Unable to determine appropriate JOIN condition for tagging.' );
 189                 }
 190
 191                 // JOIN on tag_summary
 192                 $tables[] = 'tag_summary';
 193                 $join_conds['tag_summary'] = array( 'LEFT JOIN', "ts_$join_cond=$join_cond" );
 194                 $fields[] = 'ts_tags';
 195
 196                 if( $wgUseTagFilter && $filter_tag ) {
 197                         // Somebody wants to filter on a tag.
 198                         // Add an INNER JOIN on change_tag
 199
 200                         // FORCE INDEX -- change_tags will almost ALWAYS be the correct query plan.
 201                         global $wgOldChangeTagsIndex;
 202                         $index = $wgOldChangeTagsIndex ? 'ct_tag' : 'change_tag_tag_id';
 203                         $options['USE INDEX'] = array( 'change_tag' => $index );
 204                         unset( $options['FORCE INDEX'] );
 205                         $tables[] = 'change_tag';
 206                         $join_conds['change_tag'] = array( 'INNER JOIN', "ct_$join_cond=$join_cond" );
 207                         $conds['ct_tag'] = $filter_tag;
 208                 }
 209         }
 210
 211         /**
 212          * Build a text box to select a change tag
 213          *
 214          * @param $selected String: tag to select by default
 215          * @param $fullForm Boolean:
 216          *        - if false, then it returns an array of (label, form).
 217          *        - if true, it returns an entire form around the selector.
 218          * @param $title Title object to send the form to.
 219          *        Used when, and only when $fullForm is true.
 220          * @return String or array:
 221          *        - if $fullForm is false: Array with
 222          *        - if $fullForm is true: String, html fragment
 223          */
 224         public static function buildTagFilterSelector( $selected='', $fullForm = false, Title $title = null ) {
 225                 global $wgUseTagFilter;
 226
 227                 if ( !$wgUseTagFilter || !count( self::listDefinedTags() ) )
 228                         return $fullForm ? '' : array();
 229
 230                 $data = array( Html::rawElement( 'label', array( 'for' => 'tagfilter' ), wfMsgExt( 'tag-filter', 'parseinline' ) ),
 231                         Xml::input( 'tagfilter', 20, $selected, array( 'class' => 'mw-tagfilter-input' ) ) );
 232
 233                 if ( !$fullForm ) {
 234                         return $data;
 235                 }
 236
 237                 $html = implode( '&#160;', $data );
 238                 $html .= "\n" . Xml::element( 'input', array( 'type' => 'submit', 'value' => wfMsg( 'tag-filter-submit' ) ) );
 239                 $html .= "\n" . Html::hidden( 'title', $title->getPrefixedText() );
 240                 $html = Xml::tags( 'form', array( 'action' => $title->getLocalURL(), 'class' => 'mw-tagfilter-form', 'method' => 'get' ), $html );
 241
 242                 return $html;
 243         }
 244
 245         /**
 246          * Basically lists defined tags which count even if they aren't applied to anything.
 247          * Tags on items in table 'change_tag' which are not (or no longer) in table 'valid_tag'
 248          * are not included.
 249          *
 250          * Tries memcached first.
 251          *
 252          * @return Array of strings: tags
 253          */
 254         static function listDefinedTags() {
 255                 // Caching...
 256                 global $wgMemc;
 257                 $key = wfMemcKey( 'valid-tags' );
 258                 $tags = $wgMemc->get( $key );
 259                 if ( $tags ) {
 260                         return $tags;
 261                 }
 262
 263                 $emptyTags = array();
 264
 265                 // Some DB stuff
 266                 $dbr = wfGetDB( DB_SLAVE );
 267                 $res = $dbr->select( 'valid_tag', 'vt_tag', array(), __METHOD__ );
 268                 foreach ( $res as $row ) {
 269                         $emptyTags[] = $row->vt_tag;
 270                 }
 271
 272                 wfRunHooks( 'ListDefinedTags', array( &$emptyTags ) );
 273
 274                 $emptyTags = array_filter( array_unique( $emptyTags ) );
 275
 276                 // Short-term caching.
 277                 $wgMemc->set( $key, $emptyTags, 300 );
 278                 return $emptyTags;
 279         }
 280 }