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