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[mediawiki.git] / includes / ChangeTags.php

<?php
/**
 * Recent changes tagging.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 * http://www.gnu.org/copyleft/gpl.html
 *
 * @file
 */

class ChangeTags {
        /**
         * Creates HTML for the given tags
         *
         * @param string $tags Comma-separated list of tags
         * @param string $page A label for the type of action which is being displayed,
         *   for example: 'history', 'contributions' or 'newpages'
         * @return array Array with two items: (html, classes)
         *   - html: String: HTML for displaying the tags (empty string when param $tags is empty)
         *   - classes: Array of strings: CSS classes used in the generated html, one class for each tag
         */
        public static function formatSummaryRow( $tags, $page ) {
                global $wgLang;

                $tags = explode( ',', $tags );

                // XXX(Ori Livneh, 2014-11-08): remove once bug 73181 is resolved.
                $tags = array_diff( $tags, array( 'HHVM', '' ) );

                if ( !$tags ) {
                        return array( '', array() );
                }

                $classes = array();

                $displayTags = array();
                foreach ( $tags as $tag ) {
                        $displayTags[] = Xml::tags(
                                'span',
                                array( 'class' => 'mw-tag-marker ' .
                                                                Sanitizer::escapeClass( "mw-tag-marker-$tag" ) ),
                                self::tagDescription( $tag )
                        );
                        $classes[] = Sanitizer::escapeClass( "mw-tag-$tag" );
                }
                $markers = wfMessage( 'tag-list-wrapper' )
                        ->numParams( count( $displayTags ) )
                        ->rawParams( $wgLang->commaList( $displayTags ) )
                        ->parse();
                $markers = Xml::tags( 'span', array( 'class' => 'mw-tag-markers' ), $markers );

                return array( $markers, $classes );
        }

        /**
         * Get a short description for a tag
         *
         * @param string $tag Tag
         *
         * @return string Short description of the tag from "mediawiki:tag-$tag" if this message exists,
         *   html-escaped version of $tag otherwise
         */
        public static function tagDescription( $tag ) {
                $msg = wfMessage( "tag-$tag" );
                return $msg->exists() ? $msg->parse() : htmlspecialchars( $tag );
        }

        /**
         * Add tags to a change given its rc_id, rev_id and/or log_id
         *
         * @param string|array $tags Tags to add to the change
         * @param int|null $rc_id The rc_id of the change to add the tags to
         * @param int|null $rev_id The rev_id of the change to add the tags to
         * @param int|null $log_id The log_id of the change to add the tags to
         * @param string $params Params to put in the ct_params field of table 'change_tag'
         *
         * @throws MWException
         * @return bool False if no changes are made, otherwise true
         *
         * @exception MWException When $rc_id, $rev_id and $log_id are all null
         */
        public static function addTags( $tags, $rc_id = null, $rev_id = null,
                $log_id = null, $params = null
        ) {
                if ( !is_array( $tags ) ) {
                        $tags = array( $tags );
                }

                $tags = array_filter( $tags ); // Make sure we're submitting all tags...

                if ( !$rc_id && !$rev_id && !$log_id ) {
                        throw new MWException( 'At least one of: RCID, revision ID, and log ID MUST be ' .
                                'specified when adding a tag to a change!' );
                }

                $dbw = wfGetDB( DB_MASTER );

                // Might as well look for rcids and so on.
                if ( !$rc_id ) {
                        // Info might be out of date, somewhat fractionally, on slave.
                        if ( $log_id ) {
                                $rc_id = $dbw->selectField(
                                        'recentchanges',
                                        'rc_id',
                                        array( 'rc_logid' => $log_id ),
                                        __METHOD__
                                );
                        } elseif ( $rev_id ) {
                                $rc_id = $dbw->selectField(
                                        'recentchanges',
                                        'rc_id',
                                        array( 'rc_this_oldid' => $rev_id ),
                                        __METHOD__
                                );
                        }
                } elseif ( !$log_id && !$rev_id ) {
                        // Info might be out of date, somewhat fractionally, on slave.
                        $log_id = $dbw->selectField(
                                'recentchanges',
                                'rc_logid',
                                array( 'rc_id' => $rc_id ),
                                __METHOD__
                        );
                        $rev_id = $dbw->selectField(
                                'recentchanges',
                                'rc_this_oldid',
                                array( 'rc_id' => $rc_id ),
                                __METHOD__
                        );
                }

                $tsConds = array_filter( array(
                        'ts_rc_id' => $rc_id,
                        'ts_rev_id' => $rev_id,
                        'ts_log_id' => $log_id )
                );

                // Update the summary row.
                // $prevTags can be out of date on slaves, especially when addTags is called consecutively,
                // causing loss of tags added recently in tag_summary table.
                $prevTags = $dbw->selectField( 'tag_summary', 'ts_tags', $tsConds, __METHOD__ );
                $prevTags = $prevTags ? $prevTags : '';
                $prevTags = array_filter( explode( ',', $prevTags ) );
                $newTags = array_unique( array_merge( $prevTags, $tags ) );
                sort( $prevTags );
                sort( $newTags );

                if ( $prevTags == $newTags ) {
                        // No change.
                        return false;
                }

                $dbw->replace(
                        'tag_summary',
                        array( 'ts_rev_id', 'ts_rc_id', 'ts_log_id' ),
                        array_filter( array_merge( $tsConds, array( 'ts_tags' => implode( ',', $newTags ) ) ) ),
                        __METHOD__
                );

                // Insert the tags rows.
                $tagsRows = array();
                foreach ( $tags as $tag ) { // Filter so we don't insert NULLs as zero accidentally.
                        $tagsRows[] = array_filter(
                                array(
                                        'ct_tag' => $tag,
                                        'ct_rc_id' => $rc_id,
                                        'ct_log_id' => $log_id,
                                        'ct_rev_id' => $rev_id,
                                        'ct_params' => $params
                                )
                        );
                }

                $dbw->insert( 'change_tag', $tagsRows, __METHOD__, array( 'IGNORE' ) );

                return true;
        }

        /**
         * Applies all tags-related changes to a query.
         * Handles selecting tags, and filtering.
         * Needs $tables to be set up properly, so we can figure out which join conditions to use.
         *
         * @param string|array $tables Table names, see DatabaseBase::select
         * @param string|array $fields Fields used in query, see DatabaseBase::select
         * @param string|array $conds Conditions used in query, see DatabaseBase::select
         * @param array $join_conds Join conditions, see DatabaseBase::select
         * @param array $options Options, see Database::select
         * @param bool|string $filter_tag Tag to select on
         *
         * @throws MWException When unable to determine appropriate JOIN condition for tagging
         */
        public static function modifyDisplayQuery( &$tables, &$fields, &$conds,
                                                                                &$join_conds, &$options, $filter_tag = false ) {
                global $wgRequest, $wgUseTagFilter;

                if ( $filter_tag === false ) {
                        $filter_tag = $wgRequest->getVal( 'tagfilter' );
                }

                // Figure out which conditions can be done.
                if ( in_array( 'recentchanges', $tables ) ) {
                        $join_cond = 'ct_rc_id=rc_id';
                } elseif ( in_array( 'logging', $tables ) ) {
                        $join_cond = 'ct_log_id=log_id';
                } elseif ( in_array( 'revision', $tables ) ) {
                        $join_cond = 'ct_rev_id=rev_id';
                } elseif ( in_array( 'archive', $tables ) ) {
                        $join_cond = 'ct_rev_id=ar_rev_id';
                } else {
                        throw new MWException( 'Unable to determine appropriate JOIN condition for tagging.' );
                }

                $fields['ts_tags'] = wfGetDB( DB_SLAVE )->buildGroupConcatField(
                        ',', 'change_tag', 'ct_tag', $join_cond
                );

                if ( $wgUseTagFilter && $filter_tag ) {
                        // Somebody wants to filter on a tag.
                        // Add an INNER JOIN on change_tag

                        $tables[] = 'change_tag';
                        $join_conds['change_tag'] = array( 'INNER JOIN', $join_cond );
                        $conds['ct_tag'] = $filter_tag;
                }
        }

        /**
         * Build a text box to select a change tag
         *
         * @param string $selected Tag to select by default
         * @param bool $fullForm
         *        - if false, then it returns an array of (label, form).
         *        - if true, it returns an entire form around the selector.
         * @param Title $title Title object to send the form to.
         *        Used when, and only when $fullForm is true.
         * @return string|array
         *        - if $fullForm is false: Array with
         *        - if $fullForm is true: String, html fragment
         */
        public static function buildTagFilterSelector( $selected = '',
                $fullForm = false, Title $title = null
        ) {
                global $wgUseTagFilter;

                if ( !$wgUseTagFilter || !count( self::listDefinedTags() ) ) {
                        return $fullForm ? '' : array();
                }

                $data = array(
                        Html::rawElement(
                                'label',
                                array( 'for' => 'tagfilter' ),
                                wfMessage( 'tag-filter' )->parse()
                        ),
                        Xml::input(
                                'tagfilter',
                                20,
                                $selected,
                                array( 'class' => 'mw-tagfilter-input mw-ui-input mw-ui-input-inline', 'id' => 'tagfilter' )
                        )
                );

                if ( !$fullForm ) {
                        return $data;
                }

                $html = implode( '&#160;', $data );
                $html .= "\n" .
                        Xml::element(
                                'input',
                                array( 'type' => 'submit', 'value' => wfMessage( 'tag-filter-submit' )->text() )
                        );
                $html .= "\n" . Html::hidden( 'title', $title->getPrefixedText() );
                $html = Xml::tags(
                        'form',
                        array( 'action' => $title->getLocalURL(), 'class' => 'mw-tagfilter-form', 'method' => 'get' ),
                        $html
                );

                return $html;
        }

        /**
         * Basically lists defined tags which count even if they aren't applied to anything.
         * Tags on items in table 'change_tag' which are not (or no longer) in table 'valid_tag'
         * are not included.
         *
         * Tries memcached first.
         *
         * @return string[] Array of strings: tags
         */
        public static function listDefinedTags() {
                // Caching...
                global $wgMemc;
                $key = wfMemcKey( 'valid-tags' );
                $tags = $wgMemc->get( $key );
                if ( $tags ) {
                        return $tags;
                }

                $emptyTags = array();

                // Some DB stuff
                $dbr = wfGetDB( DB_SLAVE );
                $res = $dbr->select( 'valid_tag', 'vt_tag', array(), __METHOD__ );
                foreach ( $res as $row ) {
                        $emptyTags[] = $row->vt_tag;
                }

                wfRunHooks( 'ListDefinedTags', array( &$emptyTags ) );

                $emptyTags = array_filter( array_unique( $emptyTags ) );

                // Short-term caching.
                $wgMemc->set( $key, $emptyTags, 300 );
                return $emptyTags;
        }

        /**
         * Returns a map of any tags used on the wiki to number of edits
         * tagged with them, ordered descending by the hitcount.
         *
         * @return array Array of string => int
         */
        public static function tagUsageStatistics() {
                $out = array();

                $dbr = wfGetDB( DB_SLAVE );
                $res = $dbr->select(
                        'change_tag',
                        array( 'ct_tag', 'hitcount' => 'count(*)' ),
                        array(),
                        __METHOD__,
                        array( 'GROUP BY' => 'ct_tag', 'ORDER BY' => 'hitcount DESC' )
                );

                foreach ( $res as $row ) {
                        $out[$row->ct_tag] = $row->hitcount;
                }
                foreach ( self::listDefinedTags() as $tag ) {
                        if ( !isset( $out[$tag] ) ) {
                                $out[$tag] = 0;
                        }
                }

                return $out;
        }
}