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 string $tags Comma-separated list of tags
  29          * @param string $page 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 string $tag tag
  66          *
  67          * @return String: Short description of the tag from "mediawiki:tag-$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 string|array $tags 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 string $params params to put in the ct_params field of table 'change_tag'
  83          *
  84          * @throws MWException
  85          * @return bool: false if no changes are made, otherwise true
  86          *
  87          * @exception MWException when $rc_id, $rev_id and $log_id are all null
  88          */
  89         static function addTags( $tags, $rc_id = null, $rev_id = null, $log_id = null, $params = null ) {
  90                 if ( !is_array( $tags ) ) {
  91                         $tags = array( $tags );
  92                 }
  93
  94                 $tags = array_filter( $tags ); // Make sure we're submitting all tags...
  95
  96                 if( !$rc_id && !$rev_id && !$log_id ) {
  97                         throw new MWException( "At least one of: RCID, revision ID, and log ID MUST be specified when adding a tag to a change!" );
  98                 }
  99
 100                 $dbr = wfGetDB( DB_SLAVE );
 101
 102                 // Might as well look for rcids and so on.
 103                 if( !$rc_id ) {
 104                         $dbr = wfGetDB( DB_MASTER ); // Info might be out of date, somewhat fractionally, on slave.
 105                         if( $log_id ) {
 106                                 $rc_id = $dbr->selectField( 'recentchanges', 'rc_id', array( 'rc_logid' => $log_id ), __METHOD__ );
 107                         } elseif( $rev_id ) {
 108                                 $rc_id = $dbr->selectField( 'recentchanges', 'rc_id', array( 'rc_this_oldid' => $rev_id ), __METHOD__ );
 109                         }
 110                 } elseif( !$log_id && !$rev_id ) {
 111                         $dbr = wfGetDB( DB_MASTER ); // Info might be out of date, somewhat fractionally, on slave.
 112                         $log_id = $dbr->selectField( 'recentchanges', 'rc_logid', array( 'rc_id' => $rc_id ), __METHOD__ );
 113                         $rev_id = $dbr->selectField( 'recentchanges', 'rc_this_oldid', array( 'rc_id' => $rc_id ), __METHOD__ );
 114                 }
 115
 116                 $tsConds = array_filter( array( 'ts_rc_id' => $rc_id, 'ts_rev_id' => $rev_id, 'ts_log_id' => $log_id ) );
 117
 118                 ## Update the summary row.
 119                 $prevTags = $dbr->selectField( 'tag_summary', 'ts_tags', $tsConds, __METHOD__ );
 120                 $prevTags = $prevTags ? $prevTags : '';
 121                 $prevTags = array_filter( explode( ',', $prevTags ) );
 122                 $newTags = array_unique( array_merge( $prevTags, $tags ) );
 123                 sort( $prevTags );
 124                 sort( $newTags );
 125
 126                 if ( $prevTags == $newTags ) {
 127                         // No change.
 128                         return false;
 129                 }
 130
 131                 $dbw = wfGetDB( DB_MASTER );
 132                 $dbw->replace(
 133                         'tag_summary',
 134                         array( 'ts_rev_id', 'ts_rc_id', 'ts_log_id' ),
 135                         array_filter( array_merge( $tsConds, array( 'ts_tags' => implode( ',', $newTags ) ) ) ),
 136                         __METHOD__
 137                 );
 138
 139                 // Insert the tags rows.
 140                 $tagsRows = array();
 141                 foreach( $tags as $tag ) { // Filter so we don't insert NULLs as zero accidentally.
 142                         $tagsRows[] = array_filter(
 143                                 array(
 144                                         'ct_tag' => $tag,
 145                                         'ct_rc_id' => $rc_id,
 146                                         'ct_log_id' => $log_id,
 147                                         'ct_rev_id' => $rev_id,
 148                                         'ct_params' => $params
 149                                 )
 150                         );
 151                 }
 152
 153                 $dbw->insert( 'change_tag', $tagsRows, __METHOD__, array( 'IGNORE' ) );
 154
 155                 return true;
 156         }
 157
 158         /**
 159          * Applies all tags-related changes to a query.
 160          * Handles selecting tags, and filtering.
 161          * Needs $tables to be set up properly, so we can figure out which join conditions to use.
 162          *
 163          * @param string|array $tables Table names, see DatabaseBase::select
 164          * @param string|array $fields Fields used in query, see DatabaseBase::select
 165          * @param string|array $conds conditions used in query, see DatabaseBase::select
 166          * @param $join_conds Array: join conditions, see DatabaseBase::select
 167          * @param array $options options, see Database::select
 168          * @param bool|string $filter_tag Tag to select on
 169          *
 170          * @throws MWException When unable to determine appropriate JOIN condition for tagging
 171          */
 172         static function modifyDisplayQuery( &$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 string $selected 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
 231                 $data = array( Html::rawElement( 'label', array( 'for' => 'tagfilter' ), wfMessage( 'tag-filter' )->parse() ),
 232                         Xml::input( 'tagfilter', 20, $selected, array( 'class' => 'mw-tagfilter-input' ) ) );
 233
 234                 if ( !$fullForm ) {
 235                         return $data;
 236                 }
 237
 238                 $html = implode( '&#160;', $data );
 239                 $html .= "\n" . Xml::element( 'input', array( 'type' => 'submit', 'value' => wfMessage( 'tag-filter-submit' )->text() ) );
 240                 $html .= "\n" . Html::hidden( 'title', $title->getPrefixedText() );
 241                 $html = Xml::tags( 'form', array( 'action' => $title->getLocalURL(), 'class' => 'mw-tagfilter-form', 'method' => 'get' ), $html );
 242
 243                 return $html;
 244         }
 245
 246         /**
 247          * Basically lists defined tags which count even if they aren't applied to anything.
 248          * Tags on items in table 'change_tag' which are not (or no longer) in table 'valid_tag'
 249          * are not included.
 250          *
 251          * Tries memcached first.
 252          *
 253          * @return Array of strings: tags
 254          */
 255         static function listDefinedTags() {
 256                 // Caching...
 257                 global $wgMemc;
 258                 $key = wfMemcKey( 'valid-tags' );
 259                 $tags = $wgMemc->get( $key );
 260                 if ( $tags ) {
 261                         return $tags;
 262                 }
 263
 264                 $emptyTags = array();
 265
 266                 // Some DB stuff
 267                 $dbr = wfGetDB( DB_SLAVE );
 268                 $res = $dbr->select( 'valid_tag', 'vt_tag', array(), __METHOD__ );
 269                 foreach ( $res as $row ) {
 270                         $emptyTags[] = $row->vt_tag;
 271                 }
 272
 273                 wfRunHooks( 'ListDefinedTags', array( &$emptyTags ) );
 274
 275                 $emptyTags = array_filter( array_unique( $emptyTags ) );
 276
 277                 // Short-term caching.
 278                 $wgMemc->set( $key, $emptyTags, 300 );
 279                 return $emptyTags;
 280         }
 281 }