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
  44                 $classes = array();
  45
  46                 $tags = explode( ',', $tags );
  47                 $displayTags = array();
  48                 foreach ( $tags as $tag ) {
  49                         $displayTags[] = Xml::tags(
  50                                 'span',
  51                                 array( 'class' => 'mw-tag-marker ' .
  52                                                                 Sanitizer::escapeClass( "mw-tag-marker-$tag" ) ),
  53                                 self::tagDescription( $tag )
  54                         );
  55                         $classes[] = Sanitizer::escapeClass( "mw-tag-$tag" );
  56                 }
  57                 $markers = wfMessage( 'tag-list-wrapper' )
  58                         ->numParams( count( $displayTags ) )
  59                         ->rawParams( $wgLang->commaList( $displayTags ) )
  60                         ->parse();
  61                 $markers = Xml::tags( 'span', array( 'class' => 'mw-tag-markers' ), $markers );
  62
  63                 return array( $markers, $classes );
  64         }
  65
  66         /**
  67          * Get a short description for a tag
  68          *
  69          * @param string $tag tag
  70          *
  71          * @return String: Short description of the tag from "mediawiki:tag-$tag" if this message exists,
  72          *                 html-escaped version of $tag otherwise
  73          */
  74         static function tagDescription( $tag ) {
  75                 $msg = wfMessage( "tag-$tag" );
  76                 return $msg->exists() ? $msg->parse() : htmlspecialchars( $tag );
  77         }
  78
  79         /**
  80          * Add tags to a change given its rc_id, rev_id and/or log_id
  81          *
  82          * @param string|array $tags Tags to add to the change
  83          * @param $rc_id int: rc_id of the change to add the tags to
  84          * @param $rev_id int: rev_id of the change to add the tags to
  85          * @param $log_id int: log_id of the change to add the tags to
  86          * @param string $params params to put in the ct_params field of table 'change_tag'
  87          *
  88          * @throws MWException
  89          * @return bool: false if no changes are made, otherwise true
  90          *
  91          * @exception MWException when $rc_id, $rev_id and $log_id are all null
  92          */
  93         static function addTags( $tags, $rc_id = null, $rev_id = null, $log_id = null, $params = null ) {
  94                 if ( !is_array( $tags ) ) {
  95                         $tags = array( $tags );
  96                 }
  97
  98                 $tags = array_filter( $tags ); // Make sure we're submitting all tags...
  99
 100                 if ( !$rc_id && !$rev_id && !$log_id ) {
 101                         throw new MWException( "At least one of: RCID, revision ID, and log ID MUST be specified when adding a tag to a change!" );
 102                 }
 103
 104                 $dbr = wfGetDB( DB_SLAVE );
 105
 106                 // Might as well look for rcids and so on.
 107                 if ( !$rc_id ) {
 108                         $dbr = wfGetDB( DB_MASTER ); // Info might be out of date, somewhat fractionally, on slave.
 109                         if ( $log_id ) {
 110                                 $rc_id = $dbr->selectField( 'recentchanges', 'rc_id', array( 'rc_logid' => $log_id ), __METHOD__ );
 111                         } elseif ( $rev_id ) {
 112                                 $rc_id = $dbr->selectField( 'recentchanges', 'rc_id', array( 'rc_this_oldid' => $rev_id ), __METHOD__ );
 113                         }
 114                 } elseif ( !$log_id && !$rev_id ) {
 115                         $dbr = wfGetDB( DB_MASTER ); // Info might be out of date, somewhat fractionally, on slave.
 116                         $log_id = $dbr->selectField( 'recentchanges', 'rc_logid', array( 'rc_id' => $rc_id ), __METHOD__ );
 117                         $rev_id = $dbr->selectField( 'recentchanges', 'rc_this_oldid', array( 'rc_id' => $rc_id ), __METHOD__ );
 118                 }
 119
 120                 $tsConds = array_filter( array( 'ts_rc_id' => $rc_id, 'ts_rev_id' => $rev_id, 'ts_log_id' => $log_id ) );
 121
 122                 ## Update the summary row.
 123                 $prevTags = $dbr->selectField( 'tag_summary', 'ts_tags', $tsConds, __METHOD__ );
 124                 $prevTags = $prevTags ? $prevTags : '';
 125                 $prevTags = array_filter( explode( ',', $prevTags ) );
 126                 $newTags = array_unique( array_merge( $prevTags, $tags ) );
 127                 sort( $prevTags );
 128                 sort( $newTags );
 129
 130                 if ( $prevTags == $newTags ) {
 131                         // No change.
 132                         return false;
 133                 }
 134
 135                 $dbw = wfGetDB( DB_MASTER );
 136                 $dbw->replace(
 137                         'tag_summary',
 138                         array( 'ts_rev_id', 'ts_rc_id', 'ts_log_id' ),
 139                         array_filter( array_merge( $tsConds, array( 'ts_tags' => implode( ',', $newTags ) ) ) ),
 140                         __METHOD__
 141                 );
 142
 143                 // Insert the tags rows.
 144                 $tagsRows = array();
 145                 foreach ( $tags as $tag ) { // Filter so we don't insert NULLs as zero accidentally.
 146                         $tagsRows[] = array_filter(
 147                                 array(
 148                                         'ct_tag' => $tag,
 149                                         'ct_rc_id' => $rc_id,
 150                                         'ct_log_id' => $log_id,
 151                                         'ct_rev_id' => $rev_id,
 152                                         'ct_params' => $params
 153                                 )
 154                         );
 155                 }
 156
 157                 $dbw->insert( 'change_tag', $tagsRows, __METHOD__, array( 'IGNORE' ) );
 158
 159                 return true;
 160         }
 161
 162         /**
 163          * Applies all tags-related changes to a query.
 164          * Handles selecting tags, and filtering.
 165          * Needs $tables to be set up properly, so we can figure out which join conditions to use.
 166          *
 167          * @param string|array $tables Table names, see DatabaseBase::select
 168          * @param string|array $fields Fields used in query, see DatabaseBase::select
 169          * @param string|array $conds conditions used in query, see DatabaseBase::select
 170          * @param $join_conds Array: join conditions, see DatabaseBase::select
 171          * @param array $options options, see Database::select
 172          * @param bool|string $filter_tag Tag to select on
 173          *
 174          * @throws MWException When unable to determine appropriate JOIN condition for tagging
 175          */
 176         static function modifyDisplayQuery( &$tables, &$fields, &$conds,
 177                                                                                 &$join_conds, &$options, $filter_tag = false ) {
 178                 global $wgRequest, $wgUseTagFilter;
 179
 180                 if ( $filter_tag === false ) {
 181                         $filter_tag = $wgRequest->getVal( 'tagfilter' );
 182                 }
 183
 184                 // Figure out which conditions can be done.
 185                 if ( in_array( 'recentchanges', $tables ) ) {
 186                         $join_cond = 'rc_id';
 187                 } elseif ( in_array( 'logging', $tables ) ) {
 188                         $join_cond = 'log_id';
 189                 } elseif ( in_array( 'revision', $tables ) ) {
 190                         $join_cond = 'rev_id';
 191                 } else {
 192                         throw new MWException( 'Unable to determine appropriate JOIN condition for tagging.' );
 193                 }
 194
 195                 // JOIN on tag_summary
 196                 $tables[] = 'tag_summary';
 197                 $join_conds['tag_summary'] = array( 'LEFT JOIN', "ts_$join_cond=$join_cond" );
 198                 $fields[] = 'ts_tags';
 199
 200                 if ( $wgUseTagFilter && $filter_tag ) {
 201                         // Somebody wants to filter on a tag.
 202                         // Add an INNER JOIN on change_tag
 203
 204                         // FORCE INDEX -- change_tags will almost ALWAYS be the correct query plan.
 205                         $options['USE INDEX'] = array( 'change_tag' => 'change_tag_tag_id' );
 206                         unset( $options['FORCE INDEX'] );
 207                         $tables[] = 'change_tag';
 208                         $join_conds['change_tag'] = array( 'INNER JOIN', "ct_$join_cond=$join_cond" );
 209                         $conds['ct_tag'] = $filter_tag;
 210                 }
 211         }
 212
 213         /**
 214          * Build a text box to select a change tag
 215          *
 216          * @param string $selected tag to select by default
 217          * @param $fullForm Boolean:
 218          *        - if false, then it returns an array of (label, form).
 219          *        - if true, it returns an entire form around the selector.
 220          * @param $title Title object to send the form to.
 221          *        Used when, and only when $fullForm is true.
 222          * @return String or array:
 223          *        - if $fullForm is false: Array with
 224          *        - if $fullForm is true: String, html fragment
 225          */
 226         public static function buildTagFilterSelector( $selected = '', $fullForm = false, Title $title = null ) {
 227                 global $wgUseTagFilter;
 228
 229                 if ( !$wgUseTagFilter || !count( self::listDefinedTags() ) ) {
 230                         return $fullForm ? '' : array();
 231                 }
 232
 233                 $data = array( Html::rawElement( 'label', array( 'for' => 'tagfilter' ), wfMessage( 'tag-filter' )->parse() ),
 234                         Xml::input( 'tagfilter', 20, $selected, array( 'class' => 'mw-tagfilter-input' ) ) );
 235
 236                 if ( !$fullForm ) {
 237                         return $data;
 238                 }
 239
 240                 $html = implode( '&#160;', $data );
 241                 $html .= "\n" . Xml::element( 'input', array( 'type' => 'submit', 'value' => wfMessage( 'tag-filter-submit' )->text() ) );
 242                 $html .= "\n" . Html::hidden( 'title', $title->getPrefixedText() );
 243                 $html = Xml::tags( 'form', array( 'action' => $title->getLocalURL(), 'class' => 'mw-tagfilter-form', 'method' => 'get' ), $html );
 244
 245                 return $html;
 246         }
 247
 248         /**
 249          * Basically lists defined tags which count even if they aren't applied to anything.
 250          * Tags on items in table 'change_tag' which are not (or no longer) in table 'valid_tag'
 251          * are not included.
 252          *
 253          * Tries memcached first.
 254          *
 255          * @return Array of strings: tags
 256          */
 257         static function listDefinedTags() {
 258                 // Caching...
 259                 global $wgMemc;
 260                 $key = wfMemcKey( 'valid-tags' );
 261                 $tags = $wgMemc->get( $key );
 262                 if ( $tags ) {
 263                         return $tags;
 264                 }
 265
 266                 $emptyTags = array();
 267
 268                 // Some DB stuff
 269                 $dbr = wfGetDB( DB_SLAVE );
 270                 $res = $dbr->select( 'valid_tag', 'vt_tag', array(), __METHOD__ );
 271                 foreach ( $res as $row ) {
 272                         $emptyTags[] = $row->vt_tag;
 273                 }
 274
 275                 wfRunHooks( 'ListDefinedTags', array( &$emptyTags ) );
 276
 277                 $emptyTags = array_filter( array_unique( $emptyTags ) );
 278
 279                 // Short-term caching.
 280                 $wgMemc->set( $key, $emptyTags, 300 );
 281                 return $emptyTags;
 282         }
 283 }