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Diffstat (limited to 'includes/changetags/ChangeTags.php')
| -rw-r--r-- | includes/changetags/ChangeTags.php | 1258 |
1 files changed, 1258 insertions, 0 deletions
diff --git a/includes/changetags/ChangeTags.php b/includes/changetags/ChangeTags.php new file mode 100644 index 00000000..12f738fe --- /dev/null +++ b/includes/changetags/ChangeTags.php @@ -0,0 +1,1258 @@ +<?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 + * @ingroup Change tagging + */ + +class ChangeTags { + /** + * Can't delete tags with more than this many uses. Similar in intent to + * the bigdelete user right + * @todo Use the job queue for tag deletion to avoid this restriction + */ + const MAX_DELETE_USES = 5000; + + /** + * 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 $wgLang; + + if ( !$tags ) { + return array( '', array() ); + } + + $classes = array(); + + $tags = explode( ',', $tags ); + $displayTags = array(); + foreach ( $tags as $tag ) { + if ( !$tag ) { + continue; + } + $description = self::tagDescription( $tag ); + if ( $description === false ) { + continue; + } + $displayTags[] = Xml::tags( + 'span', + array( 'class' => 'mw-tag-marker ' . + Sanitizer::escapeClass( "mw-tag-marker-$tag" ) ), + $description + ); + $classes[] = Sanitizer::escapeClass( "mw-tag-$tag" ); + } + + if ( !$displayTags ) { + return array( '', array() ); + } + + $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, $classes ); + } + + /** + * Get a short description for a tag. + * + * Checks if message key "mediawiki:tag-$tag" exists. If it does not, + * returns the HTML-escaped tag name. Uses the message if the message + * exists, provided it is not disabled. If the message is disabled, + * we consider the tag hidden, and return false. + * + * @param string $tag Tag + * @return string|bool Tag description or false if tag is to be hidden. + * @since 1.25 Returns false if tag is to be hidden. + */ + public static function tagDescription( $tag ) { + $msg = wfMessage( "tag-$tag" ); + if ( !$msg->exists() ) { + // No such message, so return the HTML-escaped tag name. + return htmlspecialchars( $tag ); + } + if ( $msg->isDisabled() ) { + // The message exists but is disabled, hide the tag. + return false; + } + + // Message exists and isn't disabled, use it. + return $msg->parse(); + } + + /** + * 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 + */ + public static function addTags( $tags, $rc_id = null, $rev_id = null, + $log_id = null, $params = null + ) { + $result = self::updateTags( $tags, null, $rc_id, $rev_id, $log_id, $params ); + return (bool)$result[0]; + } + + /** + * Add and remove tags to/from a change given its rc_id, rev_id and/or log_id, + * without verifying that the tags exist or are valid. If a tag is present in + * both $tagsToAdd and $tagsToRemove, it will be removed. + * + * This function should only be used by extensions to manipulate tags they + * have registered using the ListDefinedTags hook. When dealing with user + * input, call updateTagsWithChecks() instead. + * + * @param string|array|null $tagsToAdd Tags to add to the change + * @param string|array|null $tagsToRemove Tags to remove from the change + * @param int|null &$rc_id The rc_id of the change to add the tags to. + * Pass a variable whose value is null if the rc_id is not relevant or unknown. + * @param int|null &$rev_id The rev_id of the change to add the tags to. + * Pass a variable whose value is null if the rev_id is not relevant or unknown. + * @param int|null &$log_id The log_id of the change to add the tags to. + * Pass a variable whose value is null if the log_id is not relevant or unknown. + * @param string $params Params to put in the ct_params field of table + * 'change_tag' when adding tags + * + * @throws MWException When $rc_id, $rev_id and $log_id are all null + * @return array Index 0 is an array of tags actually added, index 1 is an + * array of tags actually removed, index 2 is an array of tags present on the + * revision or log entry before any changes were made + * + * @since 1.25 + */ + public static function updateTags( + $tagsToAdd, $tagsToRemove, + &$rc_id = null, &$rev_id = null, &$log_id = null, $params = null + ) { + + $tagsToAdd = array_filter( (array)$tagsToAdd ); // Make sure we're submitting all tags... + $tagsToRemove = array_filter( (array)$tagsToRemove ); + + 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 or removing a tag from 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. + // LogEntry/LogPage and WikiPage match rev/log/rc timestamps, + // so use that relation to avoid full table scans. + if ( $log_id ) { + $rc_id = $dbw->selectField( + array( 'logging', 'recentchanges' ), + 'rc_id', + array( + 'log_id' => $log_id, + 'rc_timestamp = log_timestamp', + 'rc_logid = log_id' + ), + __METHOD__ + ); + } elseif ( $rev_id ) { + $rc_id = $dbw->selectField( + array( 'revision', 'recentchanges' ), + 'rc_id', + array( + 'rev_id' => $rev_id, + 'rc_timestamp = rev_timestamp', + 'rc_this_oldid = rev_id' + ), + __METHOD__ + ); + } + } elseif ( !$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__ + ); + } + + // update the tag_summary row + $prevTags = array(); + if ( !self::updateTagSummaryRow( $tagsToAdd, $tagsToRemove, $rc_id, $rev_id, + $log_id, $prevTags ) ) { + + // nothing to do + return array( array(), array(), $prevTags ); + } + + // insert a row into change_tag for each new tag + if ( count( $tagsToAdd ) ) { + $tagsRows = array(); + foreach ( $tagsToAdd as $tag ) { + // Filter so we don't insert NULLs as zero accidentally. + // Keep in mind that $rc_id === null means "I don't care/know about the + // rc_id, just delete $tag on this revision/log entry". It doesn't + // mean "only delete tags on this revision/log WHERE rc_id IS NULL". + $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' ) ); + } + + // delete from change_tag + if ( count( $tagsToRemove ) ) { + foreach ( $tagsToRemove as $tag ) { + $conds = array_filter( + array( + 'ct_tag' => $tag, + 'ct_rc_id' => $rc_id, + 'ct_log_id' => $log_id, + 'ct_rev_id' => $rev_id + ) + ); + $dbw->delete( 'change_tag', $conds, __METHOD__ ); + } + } + + self::purgeTagUsageCache(); + return array( $tagsToAdd, $tagsToRemove, $prevTags ); + } + + /** + * Adds or removes a given set of tags to/from the relevant row of the + * tag_summary table. Modifies the tagsToAdd and tagsToRemove arrays to + * reflect the tags that were actually added and/or removed. + * + * @param array &$tagsToAdd + * @param array &$tagsToRemove If a tag is present in both $tagsToAdd and + * $tagsToRemove, it will be removed + * @param int|null $rc_id Null if not known or not applicable + * @param int|null $rev_id Null if not known or not applicable + * @param int|null $log_id Null if not known or not applicable + * @param array &$prevTags Optionally outputs a list of the tags that were + * in the tag_summary row to begin with + * @return bool True if any modifications were made, otherwise false + * @since 1.25 + */ + protected static function updateTagSummaryRow( &$tagsToAdd, &$tagsToRemove, + $rc_id, $rev_id, $log_id, &$prevTags = array() ) { + + $dbw = wfGetDB( DB_MASTER ); + + $tsConds = array_filter( array( + 'ts_rc_id' => $rc_id, + 'ts_rev_id' => $rev_id, + 'ts_log_id' => $log_id + ) ); + + // Can't both add and remove a tag at the same time... + $tagsToAdd = array_diff( $tagsToAdd, $tagsToRemove ); + + // 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 ) ); + + // add tags + $tagsToAdd = array_values( array_diff( $tagsToAdd, $prevTags ) ); + $newTags = array_unique( array_merge( $prevTags, $tagsToAdd ) ); + + // remove tags + $tagsToRemove = array_values( array_intersect( $tagsToRemove, $newTags ) ); + $newTags = array_values( array_diff( $newTags, $tagsToRemove ) ); + + sort( $prevTags ); + sort( $newTags ); + if ( $prevTags == $newTags ) { + // No change. + return false; + } + + if ( !$newTags ) { + // no tags left, so delete the row altogether + $dbw->delete( 'tag_summary', $tsConds, __METHOD__ ); + } else { + $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__ + ); + } + + return true; + } + + /** + * Helper function to generate a fatal status with a 'not-allowed' type error. + * + * @param string $msgOne Message key to use in the case of one tag + * @param string $msgMulti Message key to use in the case of more than one tag + * @param array $tags Restricted tags (passed as $1 into the message, count of + * $tags passed as $2) + * @return Status + * @since 1.25 + */ + protected static function restrictedTagError( $msgOne, $msgMulti, $tags ) { + $lang = RequestContext::getMain()->getLanguage(); + $count = count( $tags ); + return Status::newFatal( ( $count > 1 ) ? $msgMulti : $msgOne, + $lang->commaList( $tags ), $count ); + } + + /** + * Is it OK to allow the user to apply all the specified tags at the same time + * as they edit/make the change? + * + * @param array $tags Tags that you are interested in applying + * @param User|null $user User whose permission you wish to check, or null if + * you don't care (e.g. maintenance scripts) + * @return Status + * @since 1.25 + */ + public static function canAddTagsAccompanyingChange( array $tags, + User $user = null ) { + + if ( !is_null( $user ) && !$user->isAllowed( 'applychangetags' ) ) { + return Status::newFatal( 'tags-apply-no-permission' ); + } + + // to be applied, a tag has to be explicitly defined + // @todo Allow extensions to define tags that can be applied by users... + $allowedTags = self::listExplicitlyDefinedTags(); + $disallowedTags = array_diff( $tags, $allowedTags ); + if ( $disallowedTags ) { + return self::restrictedTagError( 'tags-apply-not-allowed-one', + 'tags-apply-not-allowed-multi', $disallowedTags ); + } + + return Status::newGood(); + } + + /** + * Adds tags to a given change, checking whether it is allowed first, but + * without adding a log entry. Useful for cases where the tag is being added + * along with the action that generated the change (e.g. tagging an edit as + * it is being made). + * + * Extensions should not use this function, unless directly handling a user + * request to add a particular tag. Normally, extensions should call + * ChangeTags::updateTags() instead. + * + * @param array $tags Tags to apply + * @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' when adding tags + * @param User $user Who to give credit for the action + * @return Status + * @since 1.25 + */ + public static function addTagsAccompanyingChangeWithChecks( + array $tags, $rc_id, $rev_id, $log_id, $params, User $user + ) { + + // are we allowed to do this? + $result = self::canAddTagsAccompanyingChange( $tags, $user ); + if ( !$result->isOK() ) { + $result->value = null; + return $result; + } + + // do it! + self::addTags( $tags, $rc_id, $rev_id, $log_id, $params ); + + return Status::newGood( true ); + } + + /** + * Is it OK to allow the user to adds and remove the given tags tags to/from a + * change? + * + * @param array $tagsToAdd Tags that you are interested in adding + * @param array $tagsToRemove Tags that you are interested in removing + * @param User|null $user User whose permission you wish to check, or null if + * you don't care (e.g. maintenance scripts) + * @return Status + * @since 1.25 + */ + public static function canUpdateTags( array $tagsToAdd, array $tagsToRemove, + User $user = null ) { + + if ( !is_null( $user ) && !$user->isAllowed( 'changetags' ) ) { + return Status::newFatal( 'tags-update-no-permission' ); + } + + if ( $tagsToAdd ) { + // to be added, a tag has to be explicitly defined + // @todo Allow extensions to define tags that can be applied by users... + $explicitlyDefinedTags = self::listExplicitlyDefinedTags(); + $diff = array_diff( $tagsToAdd, $explicitlyDefinedTags ); + if ( $diff ) { + return self::restrictedTagError( 'tags-update-add-not-allowed-one', + 'tags-update-add-not-allowed-multi', $diff ); + } + } + + if ( $tagsToRemove ) { + // to be removed, a tag must not be defined by an extension, or equivalently it + // has to be either explicitly defined or not defined at all + // (assuming no edge case of a tag both explicitly-defined and extension-defined) + $extensionDefinedTags = self::listExtensionDefinedTags(); + $intersect = array_intersect( $tagsToRemove, $extensionDefinedTags ); + if ( $intersect ) { + return self::restrictedTagError( 'tags-update-remove-not-allowed-one', + 'tags-update-remove-not-allowed-multi', $intersect ); + } + } + + return Status::newGood(); + } + + /** + * Adds and/or removes tags to/from a given change, checking whether it is + * allowed first, and adding a log entry afterwards. + * + * Includes a call to ChangeTag::canUpdateTags(), so your code doesn't need + * to do that. However, it doesn't check whether the *_id parameters are a + * valid combination. That is up to you to enforce. See ApiTag::execute() for + * an example. + * + * @param array|null $tagsToAdd If none, pass array() or null + * @param array|null $tagsToRemove If none, pass array() or null + * @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' when adding tags + * @param string $reason Comment for the log + * @param User $user Who to give credit for the action + * @return Status If successful, the value of this Status object will be an + * object (stdClass) with the following fields: + * - logId: the ID of the added log entry, or null if no log entry was added + * (i.e. no operation was performed) + * - addedTags: an array containing the tags that were actually added + * - removedTags: an array containing the tags that were actually removed + * @since 1.25 + */ + public static function updateTagsWithChecks( $tagsToAdd, $tagsToRemove, + $rc_id, $rev_id, $log_id, $params, $reason, User $user ) { + + if ( is_null( $tagsToAdd ) ) { + $tagsToAdd = array(); + } + if ( is_null( $tagsToRemove ) ) { + $tagsToRemove = array(); + } + if ( !$tagsToAdd && !$tagsToRemove ) { + // no-op, don't bother + return Status::newGood( (object)array( + 'logId' => null, + 'addedTags' => array(), + 'removedTags' => array(), + ) ); + } + + // are we allowed to do this? + $result = self::canUpdateTags( $tagsToAdd, $tagsToRemove, $user ); + if ( !$result->isOK() ) { + $result->value = null; + return $result; + } + + // basic rate limiting + if ( $user->pingLimiter( 'changetag' ) ) { + return Status::newFatal( 'actionthrottledtext' ); + } + + // do it! + list( $tagsAdded, $tagsRemoved, $initialTags ) = self::updateTags( $tagsToAdd, + $tagsToRemove, $rc_id, $rev_id, $log_id, $params ); + if ( !$tagsAdded && !$tagsRemoved ) { + // no-op, don't log it + return Status::newGood( (object)array( + 'logId' => null, + 'addedTags' => array(), + 'removedTags' => array(), + ) ); + } + + // log it + $logEntry = new ManualLogEntry( 'tag', 'update' ); + $logEntry->setPerformer( $user ); + $logEntry->setComment( $reason ); + + // find the appropriate target page + if ( $rev_id ) { + $rev = Revision::newFromId( $rev_id ); + if ( $rev ) { + $logEntry->setTarget( $rev->getTitle() ); + } + } elseif ( $log_id ) { + // This function is from revision deletion logic and has nothing to do with + // change tags, but it appears to be the only other place in core where we + // perform logged actions on log items. + $logEntry->setTarget( RevDelLogList::suggestTarget( 0, array( $log_id ) ) ); + } + + if ( !$logEntry->getTarget() ) { + // target is required, so we have to set something + $logEntry->setTarget( SpecialPage::getTitleFor( 'Tags' ) ); + } + + $logParams = array( + '4::revid' => $rev_id, + '5::logid' => $log_id, + '6:list:tagsAdded' => $tagsAdded, + '7:number:tagsAddedCount' => count( $tagsAdded ), + '8:list:tagsRemoved' => $tagsRemoved, + '9:number:tagsRemovedCount' => count( $tagsRemoved ), + 'initialTags' => $initialTags, + ); + $logEntry->setParameters( $logParams ); + $logEntry->setRelations( array( 'Tag' => array_merge( $tagsAdded, $tagsRemoved ) ) ); + + $dbw = wfGetDB( DB_MASTER ); + $logId = $logEntry->insert( $dbw ); + // Only send this to UDP, not RC, similar to patrol events + $logEntry->publish( $logId, 'udp' ); + + return Status::newGood( (object)array( + 'logId' => $logId, + 'addedTags' => $tagsAdded, + 'removedTags' => $tagsRemoved, + ) ); + } + + /** + * 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 Affects return value, see below + * @param Title $title Title object to send the form to. Used only if $fullForm is true. + * @param bool $ooui Use an OOUI TextInputWidget as selector instead of a non-OOUI input field + * You need to call OutputPage::enableOOUI() yourself. + * @return string|array + * - if $fullForm is false: an array of (label, selector). + * - if $fullForm is true: HTML of entire form built around the selector. + */ + public static function buildTagFilterSelector( $selected = '', + $fullForm = false, Title $title = null, $ooui = false + ) { + global $wgUseTagFilter; + + if ( !$wgUseTagFilter || !count( self::listDefinedTags() ) ) { + return $fullForm ? '' : array(); + } + + $data = array( + Html::rawElement( + 'label', + array( 'for' => 'tagfilter' ), + wfMessage( 'tag-filter' )->parse() + ) + ); + + if ( $ooui ) { + $data[] = new OOUI\TextInputWidget( array( + 'id' => 'tagfilter', + 'name' => 'tagfilter', + 'value' => $selected, + 'classes' => 'mw-tagfilter-input', + ) ); + } else { + $data[] = 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( ' ', $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; + } + + /** + * Defines a tag in the valid_tag table, without checking that the tag name + * is valid. + * Extensions should NOT use this function; they can use the ListDefinedTags + * hook instead. + * + * @param string $tag Tag to create + * @since 1.25 + */ + public static function defineTag( $tag ) { + $dbw = wfGetDB( DB_MASTER ); + $dbw->replace( 'valid_tag', + array( 'vt_tag' ), + array( 'vt_tag' => $tag ), + __METHOD__ ); + + // clear the memcache of defined tags + self::purgeTagCacheAll(); + } + + /** + * Removes a tag from the valid_tag table. The tag may remain in use by + * extensions, and may still show up as 'defined' if an extension is setting + * it from the ListDefinedTags hook. + * + * @param string $tag Tag to remove + * @since 1.25 + */ + public static function undefineTag( $tag ) { + $dbw = wfGetDB( DB_MASTER ); + $dbw->delete( 'valid_tag', array( 'vt_tag' => $tag ), __METHOD__ ); + + // clear the memcache of defined tags + self::purgeTagCacheAll(); + } + + /** + * Writes a tag action into the tag management log. + * + * @param string $action + * @param string $tag + * @param string $reason + * @param User $user Who to attribute the action to + * @param int $tagCount For deletion only, how many usages the tag had before + * it was deleted. + * @return int ID of the inserted log entry + * @since 1.25 + */ + protected static function logTagManagementAction( $action, $tag, $reason, + User $user, $tagCount = null ) { + + $dbw = wfGetDB( DB_MASTER ); + + $logEntry = new ManualLogEntry( 'managetags', $action ); + $logEntry->setPerformer( $user ); + // target page is not relevant, but it has to be set, so we just put in + // the title of Special:Tags + $logEntry->setTarget( Title::newFromText( 'Special:Tags' ) ); + $logEntry->setComment( $reason ); + + $params = array( '4::tag' => $tag ); + if ( !is_null( $tagCount ) ) { + $params['5:number:count'] = $tagCount; + } + $logEntry->setParameters( $params ); + $logEntry->setRelations( array( 'Tag' => $tag ) ); + + $logId = $logEntry->insert( $dbw ); + $logEntry->publish( $logId ); + return $logId; + } + + /** + * Is it OK to allow the user to activate this tag? + * + * @param string $tag Tag that you are interested in activating + * @param User|null $user User whose permission you wish to check, or null if + * you don't care (e.g. maintenance scripts) + * @return Status + * @since 1.25 + */ + public static function canActivateTag( $tag, User $user = null ) { + if ( !is_null( $user ) && !$user->isAllowed( 'managechangetags' ) ) { + return Status::newFatal( 'tags-manage-no-permission' ); + } + + // defined tags cannot be activated (a defined tag is either extension- + // defined, in which case the extension chooses whether or not to active it; + // or user-defined, in which case it is considered active) + $definedTags = self::listDefinedTags(); + if ( in_array( $tag, $definedTags ) ) { + return Status::newFatal( 'tags-activate-not-allowed', $tag ); + } + + // non-existing tags cannot be activated + $tagUsage = self::tagUsageStatistics(); + if ( !isset( $tagUsage[$tag] ) ) { // we already know the tag is undefined + return Status::newFatal( 'tags-activate-not-found', $tag ); + } + + return Status::newGood(); + } + + /** + * Activates a tag, checking whether it is allowed first, and adding a log + * entry afterwards. + * + * Includes a call to ChangeTag::canActivateTag(), so your code doesn't need + * to do that. + * + * @param string $tag + * @param string $reason + * @param User $user Who to give credit for the action + * @param bool $ignoreWarnings Can be used for API interaction, default false + * @return Status If successful, the Status contains the ID of the added log + * entry as its value + * @since 1.25 + */ + public static function activateTagWithChecks( $tag, $reason, User $user, + $ignoreWarnings = false ) { + + // are we allowed to do this? + $result = self::canActivateTag( $tag, $user ); + if ( $ignoreWarnings ? !$result->isOK() : !$result->isGood() ) { + $result->value = null; + return $result; + } + + // do it! + self::defineTag( $tag ); + + // log it + $logId = self::logTagManagementAction( 'activate', $tag, $reason, $user ); + return Status::newGood( $logId ); + } + + /** + * Is it OK to allow the user to deactivate this tag? + * + * @param string $tag Tag that you are interested in deactivating + * @param User|null $user User whose permission you wish to check, or null if + * you don't care (e.g. maintenance scripts) + * @return Status + * @since 1.25 + */ + public static function canDeactivateTag( $tag, User $user = null ) { + if ( !is_null( $user ) && !$user->isAllowed( 'managechangetags' ) ) { + return Status::newFatal( 'tags-manage-no-permission' ); + } + + // only explicitly-defined tags can be deactivated + $explicitlyDefinedTags = self::listExplicitlyDefinedTags(); + if ( !in_array( $tag, $explicitlyDefinedTags ) ) { + return Status::newFatal( 'tags-deactivate-not-allowed', $tag ); + } + return Status::newGood(); + } + + /** + * Deactivates a tag, checking whether it is allowed first, and adding a log + * entry afterwards. + * + * Includes a call to ChangeTag::canDeactivateTag(), so your code doesn't need + * to do that. + * + * @param string $tag + * @param string $reason + * @param User $user Who to give credit for the action + * @param bool $ignoreWarnings Can be used for API interaction, default false + * @return Status If successful, the Status contains the ID of the added log + * entry as its value + * @since 1.25 + */ + public static function deactivateTagWithChecks( $tag, $reason, User $user, + $ignoreWarnings = false ) { + + // are we allowed to do this? + $result = self::canDeactivateTag( $tag, $user ); + if ( $ignoreWarnings ? !$result->isOK() : !$result->isGood() ) { + $result->value = null; + return $result; + } + + // do it! + self::undefineTag( $tag ); + + // log it + $logId = self::logTagManagementAction( 'deactivate', $tag, $reason, $user ); + return Status::newGood( $logId ); + } + + /** + * Is it OK to allow the user to create this tag? + * + * @param string $tag Tag that you are interested in creating + * @param User|null $user User whose permission you wish to check, or null if + * you don't care (e.g. maintenance scripts) + * @return Status + * @since 1.25 + */ + public static function canCreateTag( $tag, User $user = null ) { + if ( !is_null( $user ) && !$user->isAllowed( 'managechangetags' ) ) { + return Status::newFatal( 'tags-manage-no-permission' ); + } + + // no empty tags + if ( $tag === '' ) { + return Status::newFatal( 'tags-create-no-name' ); + } + + // tags cannot contain commas (used as a delimiter in tag_summary table) or + // slashes (would break tag description messages in MediaWiki namespace) + if ( strpos( $tag, ',' ) !== false || strpos( $tag, '/' ) !== false ) { + return Status::newFatal( 'tags-create-invalid-chars' ); + } + + // could the MediaWiki namespace description messages be created? + $title = Title::makeTitleSafe( NS_MEDIAWIKI, "Tag-$tag-description" ); + if ( is_null( $title ) ) { + return Status::newFatal( 'tags-create-invalid-title-chars' ); + } + + // does the tag already exist? + $tagUsage = self::tagUsageStatistics(); + if ( isset( $tagUsage[$tag] ) || in_array( $tag, self::listDefinedTags() ) ) { + return Status::newFatal( 'tags-create-already-exists', $tag ); + } + + // check with hooks + $canCreateResult = Status::newGood(); + Hooks::run( 'ChangeTagCanCreate', array( $tag, $user, &$canCreateResult ) ); + return $canCreateResult; + } + + /** + * Creates a tag by adding a row to the `valid_tag` table. + * + * Includes a call to ChangeTag::canDeleteTag(), so your code doesn't need to + * do that. + * + * @param string $tag + * @param string $reason + * @param User $user Who to give credit for the action + * @param bool $ignoreWarnings Can be used for API interaction, default false + * @return Status If successful, the Status contains the ID of the added log + * entry as its value + * @since 1.25 + */ + public static function createTagWithChecks( $tag, $reason, User $user, + $ignoreWarnings = false ) { + + // are we allowed to do this? + $result = self::canCreateTag( $tag, $user ); + if ( $ignoreWarnings ? !$result->isOK() : !$result->isGood() ) { + $result->value = null; + return $result; + } + + // do it! + self::defineTag( $tag ); + + // log it + $logId = self::logTagManagementAction( 'create', $tag, $reason, $user ); + return Status::newGood( $logId ); + } + + /** + * Permanently removes all traces of a tag from the DB. Good for removing + * misspelt or temporary tags. + * + * This function should be directly called by maintenance scripts only, never + * by user-facing code. See deleteTagWithChecks() for functionality that can + * safely be exposed to users. + * + * @param string $tag Tag to remove + * @return Status The returned status will be good unless a hook changed it + * @since 1.25 + */ + public static function deleteTagEverywhere( $tag ) { + $dbw = wfGetDB( DB_MASTER ); + $dbw->startAtomic( __METHOD__ ); + + // delete from valid_tag + self::undefineTag( $tag ); + + // find out which revisions use this tag, so we can delete from tag_summary + $result = $dbw->select( 'change_tag', + array( 'ct_rc_id', 'ct_log_id', 'ct_rev_id', 'ct_tag' ), + array( 'ct_tag' => $tag ), + __METHOD__ ); + foreach ( $result as $row ) { + // remove the tag from the relevant row of tag_summary + $tagsToAdd = array(); + $tagsToRemove = array( $tag ); + self::updateTagSummaryRow( $tagsToAdd, $tagsToRemove, $row->ct_rc_id, + $row->ct_rev_id, $row->ct_log_id ); + } + + // delete from change_tag + $dbw->delete( 'change_tag', array( 'ct_tag' => $tag ), __METHOD__ ); + + $dbw->endAtomic( __METHOD__ ); + + // give extensions a chance + $status = Status::newGood(); + Hooks::run( 'ChangeTagAfterDelete', array( $tag, &$status ) ); + // let's not allow error results, as the actual tag deletion succeeded + if ( !$status->isOK() ) { + wfDebug( 'ChangeTagAfterDelete error condition downgraded to warning' ); + $status->ok = true; + } + + // clear the memcache of defined tags + self::purgeTagCacheAll(); + + return $status; + } + + /** + * Is it OK to allow the user to delete this tag? + * + * @param string $tag Tag that you are interested in deleting + * @param User|null $user User whose permission you wish to check, or null if + * you don't care (e.g. maintenance scripts) + * @return Status + * @since 1.25 + */ + public static function canDeleteTag( $tag, User $user = null ) { + $tagUsage = self::tagUsageStatistics(); + + if ( !is_null( $user ) && !$user->isAllowed( 'managechangetags' ) ) { + return Status::newFatal( 'tags-manage-no-permission' ); + } + + if ( !isset( $tagUsage[$tag] ) && !in_array( $tag, self::listDefinedTags() ) ) { + return Status::newFatal( 'tags-delete-not-found', $tag ); + } + + if ( isset( $tagUsage[$tag] ) && $tagUsage[$tag] > self::MAX_DELETE_USES ) { + return Status::newFatal( 'tags-delete-too-many-uses', $tag, self::MAX_DELETE_USES ); + } + + $extensionDefined = self::listExtensionDefinedTags(); + if ( in_array( $tag, $extensionDefined ) ) { + // extension-defined tags can't be deleted unless the extension + // specifically allows it + $status = Status::newFatal( 'tags-delete-not-allowed' ); + } else { + // user-defined tags are deletable unless otherwise specified + $status = Status::newGood(); + } + + Hooks::run( 'ChangeTagCanDelete', array( $tag, $user, &$status ) ); + return $status; + } + + /** + * Deletes a tag, checking whether it is allowed first, and adding a log entry + * afterwards. + * + * Includes a call to ChangeTag::canDeleteTag(), so your code doesn't need to + * do that. + * + * @param string $tag + * @param string $reason + * @param User $user Who to give credit for the action + * @param bool $ignoreWarnings Can be used for API interaction, default false + * @return Status If successful, the Status contains the ID of the added log + * entry as its value + * @since 1.25 + */ + public static function deleteTagWithChecks( $tag, $reason, User $user, + $ignoreWarnings = false ) { + + // are we allowed to do this? + $result = self::canDeleteTag( $tag, $user ); + if ( $ignoreWarnings ? !$result->isOK() : !$result->isGood() ) { + $result->value = null; + return $result; + } + + // store the tag usage statistics + $tagUsage = self::tagUsageStatistics(); + $hitcount = isset( $tagUsage[$tag] ) ? $tagUsage[$tag] : 0; + + // do it! + $deleteResult = self::deleteTagEverywhere( $tag ); + if ( !$deleteResult->isOK() ) { + return $deleteResult; + } + + // log it + $logId = self::logTagManagementAction( 'delete', $tag, $reason, $user, $hitcount ); + $deleteResult->value = $logId; + return $deleteResult; + } + + /** + * Lists those tags which extensions report as being "active". + * + * @return array + * @since 1.25 + */ + public static function listExtensionActivatedTags() { + return ObjectCache::getMainWANInstance()->getWithSetCallback( + wfMemcKey( 'active-tags' ), + function() { + // Ask extensions which tags they consider active + $extensionActive = array(); + Hooks::run( 'ChangeTagsListActive', array( &$extensionActive ) ); + return $extensionActive; + }, + 300, + array( wfMemcKey( 'active-tags' ) ), + array( 'lockTSE' => INF ) + ); + } + + /** + * Basically lists defined tags which count even if they aren't applied to anything. + * It returns a union of the results of listExplicitlyDefinedTags() and + * listExtensionDefinedTags(). + * + * @return string[] Array of strings: tags + */ + public static function listDefinedTags() { + $tags1 = self::listExplicitlyDefinedTags(); + $tags2 = self::listExtensionDefinedTags(); + return array_values( array_unique( array_merge( $tags1, $tags2 ) ) ); + } + + /** + * Lists tags explicitly defined in the `valid_tag` table of the database. + * Tags in table 'change_tag' which are not in table 'valid_tag' are not + * included. + * + * Tries memcached first. + * + * @return string[] Array of strings: tags + * @since 1.25 + */ + public static function listExplicitlyDefinedTags() { + $fname = __METHOD__; + + return ObjectCache::getMainWANInstance()->getWithSetCallback( + wfMemcKey( 'valid-tags-db' ), + function() use ( $fname ) { + $dbr = wfGetDB( DB_SLAVE ); + $tags = $dbr->selectFieldValues( + 'valid_tag', 'vt_tag', array(), $fname ); + + return array_filter( array_unique( $tags ) ); + }, + 300, + array( wfMemcKey( 'valid-tags-db' ) ), + array( 'lockTSE' => INF ) + ); + } + + /** + * Lists tags defined by extensions using the ListDefinedTags hook. + * Extensions need only define those tags they deem to be in active use. + * + * Tries memcached first. + * + * @return string[] Array of strings: tags + * @since 1.25 + */ + public static function listExtensionDefinedTags() { + return ObjectCache::getMainWANInstance()->getWithSetCallback( + wfMemcKey( 'valid-tags-hook' ), + function() { + $tags = array(); + Hooks::run( 'ListDefinedTags', array( &$tags ) ); + return array_filter( array_unique( $tags ) ); + }, + 300, + array( wfMemcKey( 'valid-tags-hook' ) ), + array( 'lockTSE' => INF ) + ); + } + + /** + * Invalidates the short-term cache of defined tags used by the + * list*DefinedTags functions, as well as the tag statistics cache. + * @since 1.25 + */ + public static function purgeTagCacheAll() { + $cache = ObjectCache::getMainWANInstance(); + + $cache->touchCheckKey( wfMemcKey( 'active-tags' ) ); + $cache->touchCheckKey( wfMemcKey( 'valid-tags-db' ) ); + $cache->touchCheckKey( wfMemcKey( 'valid-tags-hook' ) ); + + self::purgeTagUsageCache(); + } + + /** + * Invalidates the tag statistics cache only. + * @since 1.25 + */ + public static function purgeTagUsageCache() { + $cache = ObjectCache::getMainWANInstance(); + + $cache->touchCheckKey( wfMemcKey( 'change-tag-statistics' ) ); + } + + /** + * Returns a map of any tags used on the wiki to number of edits + * tagged with them, ordered descending by the hitcount. + * This does not include tags defined somewhere that have never been applied. + * + * Keeps a short-term cache in memory, so calling this multiple times in the + * same request should be fine. + * + * @return array Array of string => int + */ + public static function tagUsageStatistics() { + static $cachedStats = null; + + // Process cache to avoid I/O and repeated regens during holdoff + if ( $cachedStats !== null ) { + return $cachedStats; + } + + $fname = __METHOD__; + $cachedStats = ObjectCache::getMainWANInstance()->getWithSetCallback( + wfMemcKey( 'change-tag-statistics' ), + function() use ( $fname ) { + $out = array(); + + $dbr = wfGetDB( DB_SLAVE, 'vslow' ); + $res = $dbr->select( + 'change_tag', + array( 'ct_tag', 'hitcount' => 'count(*)' ), + array(), + $fname, + array( 'GROUP BY' => 'ct_tag', 'ORDER BY' => 'hitcount DESC' ) + ); + + foreach ( $res as $row ) { + $out[$row->ct_tag] = $row->hitcount; + } + + return $out; + }, + 300, + array( wfMemcKey( 'change-tag-statistics' ) ), + array( 'lockTSE' => INF ) + ); + + return $cachedStats; + } + + /** + * Indicate whether change tag editing UI is relevant + * + * Returns true if the user has the necessary right and there are any + * editable tags defined. + * + * This intentionally doesn't check "any addable || any deletable", because + * it seems like it would be more confusing than useful if the checkboxes + * suddenly showed up because some abuse filter stopped defining a tag and + * then suddenly disappeared when someone deleted all uses of that tag. + * + * @param User $user + * @return bool + */ + public static function showTagEditingUI( User $user ) { + return $user->isAllowed( 'changetags' ) && (bool)self::listExplicitlyDefinedTags(); + } +} |