includes/changetags/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  * @ingroup Change tagging
  22  */
  23
  24 use MediaWiki\MediaWikiServices;
  25 use Wikimedia\Rdbms\Database;
  26
  27 class ChangeTags {
  28         /**
  29          * Can't delete tags with more than this many uses. Similar in intent to
  30          * the bigdelete user right
  31          * @todo Use the job queue for tag deletion to avoid this restriction
  32          */
  33         const MAX_DELETE_USES = 5000;
  34
  35         private static $definedSoftwareTags = [
  36                 'mw-contentmodelchange',
  37                 'mw-new-redirect',
  38                 'mw-removed-redirect',
  39                 'mw-changed-redirect-target',
  40                 'mw-blank',
  41                 'mw-replace',
  42                 'mw-rollback'
  43         ];
  44
  45         /**
  46          * Loads defined core tags, checks for invalid types (if not array),
  47          * and filters for supported and enabled (if $all is false) tags only.
  48          *
  49          * @param bool $all If true, return all valid defined tags. Otherwise, return only enabled ones.
  50          * @return array Array of all defined/enabled tags.
  51          */
  52         public static function getSoftwareTags( $all = false ) {
  53                 global $wgSoftwareTags;
  54                 $softwareTags = [];
  55
  56                 if ( !is_array( $wgSoftwareTags ) ) {
  57                         wfWarn( 'wgSoftwareTags should be associative array of enabled tags.
  58                         Please refer to documentation for the list of tags you can enable' );
  59                         return $softwareTags;
  60                 }
  61
  62                 $availableSoftwareTags = !$all ?
  63                         array_keys( array_filter( $wgSoftwareTags ) ) :
  64                         array_keys( $wgSoftwareTags );
  65
  66                 $softwareTags = array_intersect(
  67                         $availableSoftwareTags,
  68                         self::$definedSoftwareTags
  69                 );
  70
  71                 return $softwareTags;
  72         }
  73
  74         /**
  75          * Creates HTML for the given tags
  76          *
  77          * @param string $tags Comma-separated list of tags
  78          * @param string $page A label for the type of action which is being displayed,
  79          *   for example: 'history', 'contributions' or 'newpages'
  80          * @param IContextSource|null $context
  81          * @note Even though it takes null as a valid argument, an IContextSource is preferred
  82          *       in a new code, as the null value is subject to change in the future
  83          * @return array Array with two items: (html, classes)
  84          *   - html: String: HTML for displaying the tags (empty string when param $tags is empty)
  85          *   - classes: Array of strings: CSS classes used in the generated html, one class for each tag
  86          */
  87         public static function formatSummaryRow( $tags, $page, IContextSource $context = null ) {
  88                 if ( !$tags ) {
  89                         return [ '', [] ];
  90                 }
  91                 if ( !$context ) {
  92                         $context = RequestContext::getMain();
  93                 }
  94
  95                 $classes = [];
  96
  97                 $tags = explode( ',', $tags );
  98                 $displayTags = [];
  99                 foreach ( $tags as $tag ) {
 100                         if ( !$tag ) {
 101                                 continue;
 102                         }
 103                         $description = self::tagDescription( $tag, $context );
 104                         if ( $description === false ) {
 105                                 continue;
 106                         }
 107                         $displayTags[] = Xml::tags(
 108                                 'span',
 109                                 [ 'class' => 'mw-tag-marker ' .
 110                                                                 Sanitizer::escapeClass( "mw-tag-marker-$tag" ) ],
 111                                 $description
 112                         );
 113                         $classes[] = Sanitizer::escapeClass( "mw-tag-$tag" );
 114                 }
 115
 116                 if ( !$displayTags ) {
 117                         return [ '', [] ];
 118                 }
 119
 120                 $markers = $context->msg( 'tag-list-wrapper' )
 121                         ->numParams( count( $displayTags ) )
 122                         ->rawParams( $context->getLanguage()->commaList( $displayTags ) )
 123                         ->parse();
 124                 $markers = Xml::tags( 'span', [ 'class' => 'mw-tag-markers' ], $markers );
 125
 126                 return [ $markers, $classes ];
 127         }
 128
 129         /**
 130          * Get a short description for a tag.
 131          *
 132          * Checks if message key "mediawiki:tag-$tag" exists. If it does not,
 133          * returns the HTML-escaped tag name. Uses the message if the message
 134          * exists, provided it is not disabled. If the message is disabled,
 135          * we consider the tag hidden, and return false.
 136          *
 137          * @param string $tag Tag
 138          * @param IContextSource $context
 139          * @return string|bool Tag description or false if tag is to be hidden.
 140          * @since 1.25 Returns false if tag is to be hidden.
 141          */
 142         public static function tagDescription( $tag, IContextSource $context ) {
 143                 $msg = $context->msg( "tag-$tag" );
 144                 if ( !$msg->exists() ) {
 145                         // No such message, so return the HTML-escaped tag name.
 146                         return htmlspecialchars( $tag );
 147                 }
 148                 if ( $msg->isDisabled() ) {
 149                         // The message exists but is disabled, hide the tag.
 150                         return false;
 151                 }
 152
 153                 // Message exists and isn't disabled, use it.
 154                 return $msg->parse();
 155         }
 156
 157         /**
 158          * Get the message object for the tag's long description.
 159          *
 160          * Checks if message key "mediawiki:tag-$tag-description" exists. If it does not,
 161          * or if message is disabled, returns false. Otherwise, returns the message object
 162          * for the long description.
 163          *
 164          * @param string $tag Tag
 165          * @param IContextSource $context
 166          * @return Message|bool Message object of the tag long description or false if
 167          *  there is no description.
 168          */
 169         public static function tagLongDescriptionMessage( $tag, IContextSource $context ) {
 170                 $msg = $context->msg( "tag-$tag-description" );
 171                 if ( !$msg->exists() ) {
 172                         return false;
 173                 }
 174                 if ( $msg->isDisabled() ) {
 175                         // The message exists but is disabled, hide the description.
 176                         return false;
 177                 }
 178
 179                 // Message exists and isn't disabled, use it.
 180                 return $msg;
 181         }
 182
 183         /**
 184          * Add tags to a change given its rc_id, rev_id and/or log_id
 185          *
 186          * @param string|string[] $tags Tags to add to the change
 187          * @param int|null $rc_id The rc_id of the change to add the tags to
 188          * @param int|null $rev_id The rev_id of the change to add the tags to
 189          * @param int|null $log_id The log_id of the change to add the tags to
 190          * @param string $params Params to put in the ct_params field of table 'change_tag'
 191          * @param RecentChange|null $rc Recent change, in case the tagging accompanies the action
 192          * (this should normally be the case)
 193          *
 194          * @throws MWException
 195          * @return bool False if no changes are made, otherwise true
 196          */
 197         public static function addTags( $tags, $rc_id = null, $rev_id = null,
 198                 $log_id = null, $params = null, RecentChange $rc = null
 199         ) {
 200                 $result = self::updateTags( $tags, null, $rc_id, $rev_id, $log_id, $params, $rc );
 201                 return (bool)$result[0];
 202         }
 203
 204         /**
 205          * Add and remove tags to/from a change given its rc_id, rev_id and/or log_id,
 206          * without verifying that the tags exist or are valid. If a tag is present in
 207          * both $tagsToAdd and $tagsToRemove, it will be removed.
 208          *
 209          * This function should only be used by extensions to manipulate tags they
 210          * have registered using the ListDefinedTags hook. When dealing with user
 211          * input, call updateTagsWithChecks() instead.
 212          *
 213          * @param string|array|null $tagsToAdd Tags to add to the change
 214          * @param string|array|null $tagsToRemove Tags to remove from the change
 215          * @param int|null &$rc_id The rc_id of the change to add the tags to.
 216          * Pass a variable whose value is null if the rc_id is not relevant or unknown.
 217          * @param int|null &$rev_id The rev_id of the change to add the tags to.
 218          * Pass a variable whose value is null if the rev_id is not relevant or unknown.
 219          * @param int|null &$log_id The log_id of the change to add the tags to.
 220          * Pass a variable whose value is null if the log_id is not relevant or unknown.
 221          * @param string $params Params to put in the ct_params field of table
 222          * 'change_tag' when adding tags
 223          * @param RecentChange|null $rc Recent change being tagged, in case the tagging accompanies
 224          * the action
 225          * @param User|null $user Tagging user, in case the tagging is subsequent to the tagged action
 226          *
 227          * @throws MWException When $rc_id, $rev_id and $log_id are all null
 228          * @return array Index 0 is an array of tags actually added, index 1 is an
 229          * array of tags actually removed, index 2 is an array of tags present on the
 230          * revision or log entry before any changes were made
 231          *
 232          * @since 1.25
 233          */
 234         public static function updateTags( $tagsToAdd, $tagsToRemove, &$rc_id = null,
 235                 &$rev_id = null, &$log_id = null, $params = null, RecentChange $rc = null,
 236                 User $user = null
 237         ) {
 238                 $tagsToAdd = array_filter( (array)$tagsToAdd ); // Make sure we're submitting all tags...
 239                 $tagsToRemove = array_filter( (array)$tagsToRemove );
 240
 241                 if ( !$rc_id && !$rev_id && !$log_id ) {
 242                         throw new MWException( 'At least one of: RCID, revision ID, and log ID MUST be ' .
 243                                 'specified when adding or removing a tag from a change!' );
 244                 }
 245
 246                 $dbw = wfGetDB( DB_MASTER );
 247
 248                 // Might as well look for rcids and so on.
 249                 if ( !$rc_id ) {
 250                         // Info might be out of date, somewhat fractionally, on replica DB.
 251                         // LogEntry/LogPage and WikiPage match rev/log/rc timestamps,
 252                         // so use that relation to avoid full table scans.
 253                         if ( $log_id ) {
 254                                 $rc_id = $dbw->selectField(
 255                                         [ 'logging', 'recentchanges' ],
 256                                         'rc_id',
 257                                         [
 258                                                 'log_id' => $log_id,
 259                                                 'rc_timestamp = log_timestamp',
 260                                                 'rc_logid = log_id'
 261                                         ],
 262                                         __METHOD__
 263                                 );
 264                         } elseif ( $rev_id ) {
 265                                 $rc_id = $dbw->selectField(
 266                                         [ 'revision', 'recentchanges' ],
 267                                         'rc_id',
 268                                         [
 269                                                 'rev_id' => $rev_id,
 270                                                 'rc_timestamp = rev_timestamp',
 271                                                 'rc_this_oldid = rev_id'
 272                                         ],
 273                                         __METHOD__
 274                                 );
 275                         }
 276                 } elseif ( !$log_id && !$rev_id ) {
 277                         // Info might be out of date, somewhat fractionally, on replica DB.
 278                         $log_id = $dbw->selectField(
 279                                 'recentchanges',
 280                                 'rc_logid',
 281                                 [ 'rc_id' => $rc_id ],
 282                                 __METHOD__
 283                         );
 284                         $rev_id = $dbw->selectField(
 285                                 'recentchanges',
 286                                 'rc_this_oldid',
 287                                 [ 'rc_id' => $rc_id ],
 288                                 __METHOD__
 289                         );
 290                 }
 291
 292                 if ( $log_id && !$rev_id ) {
 293                         $rev_id = $dbw->selectField(
 294                                 'log_search',
 295                                 'ls_value',
 296                                 [ 'ls_field' => 'associated_rev_id', 'ls_log_id' => $log_id ],
 297                                 __METHOD__
 298                         );
 299                 } elseif ( !$log_id && $rev_id ) {
 300                         $log_id = $dbw->selectField(
 301                                 'log_search',
 302                                 'ls_log_id',
 303                                 [ 'ls_field' => 'associated_rev_id', 'ls_value' => $rev_id ],
 304                                 __METHOD__
 305                         );
 306                 }
 307
 308                 // update the tag_summary row
 309                 $prevTags = [];
 310                 if ( !self::updateTagSummaryRow( $tagsToAdd, $tagsToRemove, $rc_id, $rev_id,
 311                         $log_id, $prevTags )
 312                 ) {
 313                         // nothing to do
 314                         return [ [], [], $prevTags ];
 315                 }
 316
 317                 // insert a row into change_tag for each new tag
 318                 if ( count( $tagsToAdd ) ) {
 319                         $tagsRows = [];
 320                         foreach ( $tagsToAdd as $tag ) {
 321                                 // Filter so we don't insert NULLs as zero accidentally.
 322                                 // Keep in mind that $rc_id === null means "I don't care/know about the
 323                                 // rc_id, just delete $tag on this revision/log entry". It doesn't
 324                                 // mean "only delete tags on this revision/log WHERE rc_id IS NULL".
 325                                 $tagsRows[] = array_filter(
 326                                         [
 327                                                 'ct_tag' => $tag,
 328                                                 'ct_rc_id' => $rc_id,
 329                                                 'ct_log_id' => $log_id,
 330                                                 'ct_rev_id' => $rev_id,
 331                                                 'ct_params' => $params
 332                                         ]
 333                                 );
 334                         }
 335
 336                         $dbw->insert( 'change_tag', $tagsRows, __METHOD__, [ 'IGNORE' ] );
 337                 }
 338
 339                 // delete from change_tag
 340                 if ( count( $tagsToRemove ) ) {
 341                         foreach ( $tagsToRemove as $tag ) {
 342                                 $conds = array_filter(
 343                                         [
 344                                                 'ct_tag' => $tag,
 345                                                 'ct_rc_id' => $rc_id,
 346                                                 'ct_log_id' => $log_id,
 347                                                 'ct_rev_id' => $rev_id
 348                                         ]
 349                                 );
 350                                 $dbw->delete( 'change_tag', $conds, __METHOD__ );
 351                         }
 352                 }
 353
 354                 self::purgeTagUsageCache();
 355
 356                 Hooks::run( 'ChangeTagsAfterUpdateTags', [ $tagsToAdd, $tagsToRemove, $prevTags,
 357                         $rc_id, $rev_id, $log_id, $params, $rc, $user ] );
 358
 359                 return [ $tagsToAdd, $tagsToRemove, $prevTags ];
 360         }
 361
 362         /**
 363          * Adds or removes a given set of tags to/from the relevant row of the
 364          * tag_summary table. Modifies the tagsToAdd and tagsToRemove arrays to
 365          * reflect the tags that were actually added and/or removed.
 366          *
 367          * @param array &$tagsToAdd
 368          * @param array &$tagsToRemove If a tag is present in both $tagsToAdd and
 369          * $tagsToRemove, it will be removed
 370          * @param int|null $rc_id Null if not known or not applicable
 371          * @param int|null $rev_id Null if not known or not applicable
 372          * @param int|null $log_id Null if not known or not applicable
 373          * @param array &$prevTags Optionally outputs a list of the tags that were
 374          * in the tag_summary row to begin with
 375          * @return bool True if any modifications were made, otherwise false
 376          * @since 1.25
 377          */
 378         protected static function updateTagSummaryRow( &$tagsToAdd, &$tagsToRemove,
 379                 $rc_id, $rev_id, $log_id, &$prevTags = []
 380         ) {
 381                 $dbw = wfGetDB( DB_MASTER );
 382
 383                 $tsConds = array_filter( [
 384                         'ts_rc_id' => $rc_id,
 385                         'ts_rev_id' => $rev_id,
 386                         'ts_log_id' => $log_id
 387                 ] );
 388
 389                 // Can't both add and remove a tag at the same time...
 390                 $tagsToAdd = array_diff( $tagsToAdd, $tagsToRemove );
 391
 392                 // Update the summary row.
 393                 // $prevTags can be out of date on replica DBs, especially when addTags is called consecutively,
 394                 // causing loss of tags added recently in tag_summary table.
 395                 $prevTags = $dbw->selectField( 'tag_summary', 'ts_tags', $tsConds, __METHOD__ );
 396                 $prevTags = $prevTags ? $prevTags : '';
 397                 $prevTags = array_filter( explode( ',', $prevTags ) );
 398
 399                 // add tags
 400                 $tagsToAdd = array_values( array_diff( $tagsToAdd, $prevTags ) );
 401                 $newTags = array_unique( array_merge( $prevTags, $tagsToAdd ) );
 402
 403                 // remove tags
 404                 $tagsToRemove = array_values( array_intersect( $tagsToRemove, $newTags ) );
 405                 $newTags = array_values( array_diff( $newTags, $tagsToRemove ) );
 406
 407                 sort( $prevTags );
 408                 sort( $newTags );
 409                 if ( $prevTags == $newTags ) {
 410                         // No change.
 411                         return false;
 412                 }
 413
 414                 if ( !$newTags ) {
 415                         // no tags left, so delete the row altogether
 416                         $dbw->delete( 'tag_summary', $tsConds, __METHOD__ );
 417                 } else {
 418                         $dbw->replace( 'tag_summary',
 419                                 [ 'ts_rev_id', 'ts_rc_id', 'ts_log_id' ],
 420                                 array_filter( array_merge( $tsConds, [ 'ts_tags' => implode( ',', $newTags ) ] ) ),
 421                                 __METHOD__
 422                         );
 423                 }
 424
 425                 return true;
 426         }
 427
 428         /**
 429          * Helper function to generate a fatal status with a 'not-allowed' type error.
 430          *
 431          * @param string $msgOne Message key to use in the case of one tag
 432          * @param string $msgMulti Message key to use in the case of more than one tag
 433          * @param array $tags Restricted tags (passed as $1 into the message, count of
 434          * $tags passed as $2)
 435          * @return Status
 436          * @since 1.25
 437          */
 438         protected static function restrictedTagError( $msgOne, $msgMulti, $tags ) {
 439                 $lang = RequestContext::getMain()->getLanguage();
 440                 $count = count( $tags );
 441                 return Status::newFatal( ( $count > 1 ) ? $msgMulti : $msgOne,
 442                         $lang->commaList( $tags ), $count );
 443         }
 444
 445         /**
 446          * Is it OK to allow the user to apply all the specified tags at the same time
 447          * as they edit/make the change?
 448          *
 449          * @param array $tags Tags that you are interested in applying
 450          * @param User|null $user User whose permission you wish to check, or null if
 451          * you don't care (e.g. maintenance scripts)
 452          * @return Status
 453          * @since 1.25
 454          */
 455         public static function canAddTagsAccompanyingChange( array $tags, User $user = null ) {
 456                 if ( !is_null( $user ) ) {
 457                         if ( !$user->isAllowed( 'applychangetags' ) ) {
 458                                 return Status::newFatal( 'tags-apply-no-permission' );
 459                         } elseif ( $user->isBlocked() ) {
 460                                 return Status::newFatal( 'tags-apply-blocked', $user->getName() );
 461                         }
 462                 }
 463
 464                 // to be applied, a tag has to be explicitly defined
 465                 $allowedTags = self::listExplicitlyDefinedTags();
 466                 Hooks::run( 'ChangeTagsAllowedAdd', [ &$allowedTags, $tags, $user ] );
 467                 $disallowedTags = array_diff( $tags, $allowedTags );
 468                 if ( $disallowedTags ) {
 469                         return self::restrictedTagError( 'tags-apply-not-allowed-one',
 470                                 'tags-apply-not-allowed-multi', $disallowedTags );
 471                 }
 472
 473                 return Status::newGood();
 474         }
 475
 476         /**
 477          * Adds tags to a given change, checking whether it is allowed first, but
 478          * without adding a log entry. Useful for cases where the tag is being added
 479          * along with the action that generated the change (e.g. tagging an edit as
 480          * it is being made).
 481          *
 482          * Extensions should not use this function, unless directly handling a user
 483          * request to add a particular tag. Normally, extensions should call
 484          * ChangeTags::updateTags() instead.
 485          *
 486          * @param array $tags Tags to apply
 487          * @param int|null $rc_id The rc_id of the change to add the tags to
 488          * @param int|null $rev_id The rev_id of the change to add the tags to
 489          * @param int|null $log_id The log_id of the change to add the tags to
 490          * @param string $params Params to put in the ct_params field of table
 491          * 'change_tag' when adding tags
 492          * @param User $user Who to give credit for the action
 493          * @return Status
 494          * @since 1.25
 495          */
 496         public static function addTagsAccompanyingChangeWithChecks(
 497                 array $tags, $rc_id, $rev_id, $log_id, $params, User $user
 498         ) {
 499                 // are we allowed to do this?
 500                 $result = self::canAddTagsAccompanyingChange( $tags, $user );
 501                 if ( !$result->isOK() ) {
 502                         $result->value = null;
 503                         return $result;
 504                 }
 505
 506                 // do it!
 507                 self::addTags( $tags, $rc_id, $rev_id, $log_id, $params );
 508
 509                 return Status::newGood( true );
 510         }
 511
 512         /**
 513          * Is it OK to allow the user to adds and remove the given tags tags to/from a
 514          * change?
 515          *
 516          * @param array $tagsToAdd Tags that you are interested in adding
 517          * @param array $tagsToRemove Tags that you are interested in removing
 518          * @param User|null $user User whose permission you wish to check, or null if
 519          * you don't care (e.g. maintenance scripts)
 520          * @return Status
 521          * @since 1.25
 522          */
 523         public static function canUpdateTags( array $tagsToAdd, array $tagsToRemove,
 524                 User $user = null
 525         ) {
 526                 if ( !is_null( $user ) ) {
 527                         if ( !$user->isAllowed( 'changetags' ) ) {
 528                                 return Status::newFatal( 'tags-update-no-permission' );
 529                         } elseif ( $user->isBlocked() ) {
 530                                 return Status::newFatal( 'tags-update-blocked', $user->getName() );
 531                         }
 532                 }
 533
 534                 if ( $tagsToAdd ) {
 535                         // to be added, a tag has to be explicitly defined
 536                         // @todo Allow extensions to define tags that can be applied by users...
 537                         $explicitlyDefinedTags = self::listExplicitlyDefinedTags();
 538                         $diff = array_diff( $tagsToAdd, $explicitlyDefinedTags );
 539                         if ( $diff ) {
 540                                 return self::restrictedTagError( 'tags-update-add-not-allowed-one',
 541                                         'tags-update-add-not-allowed-multi', $diff );
 542                         }
 543                 }
 544
 545                 if ( $tagsToRemove ) {
 546                         // to be removed, a tag must not be defined by an extension, or equivalently it
 547                         // has to be either explicitly defined or not defined at all
 548                         // (assuming no edge case of a tag both explicitly-defined and extension-defined)
 549                         $softwareDefinedTags = self::listSoftwareDefinedTags();
 550                         $intersect = array_intersect( $tagsToRemove, $softwareDefinedTags );
 551                         if ( $intersect ) {
 552                                 return self::restrictedTagError( 'tags-update-remove-not-allowed-one',
 553                                         'tags-update-remove-not-allowed-multi', $intersect );
 554                         }
 555                 }
 556
 557                 return Status::newGood();
 558         }
 559
 560         /**
 561          * Adds and/or removes tags to/from a given change, checking whether it is
 562          * allowed first, and adding a log entry afterwards.
 563          *
 564          * Includes a call to ChangeTag::canUpdateTags(), so your code doesn't need
 565          * to do that. However, it doesn't check whether the *_id parameters are a
 566          * valid combination. That is up to you to enforce. See ApiTag::execute() for
 567          * an example.
 568          *
 569          * @param array|null $tagsToAdd If none, pass array() or null
 570          * @param array|null $tagsToRemove If none, pass array() or null
 571          * @param int|null $rc_id The rc_id of the change to add the tags to
 572          * @param int|null $rev_id The rev_id of the change to add the tags to
 573          * @param int|null $log_id The log_id of the change to add the tags to
 574          * @param string $params Params to put in the ct_params field of table
 575          * 'change_tag' when adding tags
 576          * @param string $reason Comment for the log
 577          * @param User $user Who to give credit for the action
 578          * @return Status If successful, the value of this Status object will be an
 579          * object (stdClass) with the following fields:
 580          *  - logId: the ID of the added log entry, or null if no log entry was added
 581          *    (i.e. no operation was performed)
 582          *  - addedTags: an array containing the tags that were actually added
 583          *  - removedTags: an array containing the tags that were actually removed
 584          * @since 1.25
 585          */
 586         public static function updateTagsWithChecks( $tagsToAdd, $tagsToRemove,
 587                 $rc_id, $rev_id, $log_id, $params, $reason, User $user
 588         ) {
 589                 if ( is_null( $tagsToAdd ) ) {
 590                         $tagsToAdd = [];
 591                 }
 592                 if ( is_null( $tagsToRemove ) ) {
 593                         $tagsToRemove = [];
 594                 }
 595                 if ( !$tagsToAdd && !$tagsToRemove ) {
 596                         // no-op, don't bother
 597                         return Status::newGood( (object)[
 598                                 'logId' => null,
 599                                 'addedTags' => [],
 600                                 'removedTags' => [],
 601                         ] );
 602                 }
 603
 604                 // are we allowed to do this?
 605                 $result = self::canUpdateTags( $tagsToAdd, $tagsToRemove, $user );
 606                 if ( !$result->isOK() ) {
 607                         $result->value = null;
 608                         return $result;
 609                 }
 610
 611                 // basic rate limiting
 612                 if ( $user->pingLimiter( 'changetag' ) ) {
 613                         return Status::newFatal( 'actionthrottledtext' );
 614                 }
 615
 616                 // do it!
 617                 list( $tagsAdded, $tagsRemoved, $initialTags ) = self::updateTags( $tagsToAdd,
 618                         $tagsToRemove, $rc_id, $rev_id, $log_id, $params, null, $user );
 619                 if ( !$tagsAdded && !$tagsRemoved ) {
 620                         // no-op, don't log it
 621                         return Status::newGood( (object)[
 622                                 'logId' => null,
 623                                 'addedTags' => [],
 624                                 'removedTags' => [],
 625                         ] );
 626                 }
 627
 628                 // log it
 629                 $logEntry = new ManualLogEntry( 'tag', 'update' );
 630                 $logEntry->setPerformer( $user );
 631                 $logEntry->setComment( $reason );
 632
 633                 // find the appropriate target page
 634                 if ( $rev_id ) {
 635                         $rev = Revision::newFromId( $rev_id );
 636                         if ( $rev ) {
 637                                 $logEntry->setTarget( $rev->getTitle() );
 638                         }
 639                 } elseif ( $log_id ) {
 640                         // This function is from revision deletion logic and has nothing to do with
 641                         // change tags, but it appears to be the only other place in core where we
 642                         // perform logged actions on log items.
 643                         $logEntry->setTarget( RevDelLogList::suggestTarget( null, [ $log_id ] ) );
 644                 }
 645
 646                 if ( !$logEntry->getTarget() ) {
 647                         // target is required, so we have to set something
 648                         $logEntry->setTarget( SpecialPage::getTitleFor( 'Tags' ) );
 649                 }
 650
 651                 $logParams = [
 652                         '4::revid' => $rev_id,
 653                         '5::logid' => $log_id,
 654                         '6:list:tagsAdded' => $tagsAdded,
 655                         '7:number:tagsAddedCount' => count( $tagsAdded ),
 656                         '8:list:tagsRemoved' => $tagsRemoved,
 657                         '9:number:tagsRemovedCount' => count( $tagsRemoved ),
 658                         'initialTags' => $initialTags,
 659                 ];
 660                 $logEntry->setParameters( $logParams );
 661                 $logEntry->setRelations( [ 'Tag' => array_merge( $tagsAdded, $tagsRemoved ) ] );
 662
 663                 $dbw = wfGetDB( DB_MASTER );
 664                 $logId = $logEntry->insert( $dbw );
 665                 // Only send this to UDP, not RC, similar to patrol events
 666                 $logEntry->publish( $logId, 'udp' );
 667
 668                 return Status::newGood( (object)[
 669                         'logId' => $logId,
 670                         'addedTags' => $tagsAdded,
 671                         'removedTags' => $tagsRemoved,
 672                 ] );
 673         }
 674
 675         /**
 676          * Applies all tags-related changes to a query.
 677          * Handles selecting tags, and filtering.
 678          * Needs $tables to be set up properly, so we can figure out which join conditions to use.
 679          *
 680          * WARNING: If $filter_tag contains more than one tag, this function will add DISTINCT,
 681          * which may cause performance problems for your query unless you put the ID field of your
 682          * table at the end of the ORDER BY, and set a GROUP BY equal to the ORDER BY. For example,
 683          * if you had ORDER BY foo_timestamp DESC, you will now need GROUP BY foo_timestamp, foo_id
 684          * ORDER BY foo_timestamp DESC, foo_id DESC.
 685          *
 686          * @param string|array &$tables Table names, see Database::select
 687          * @param string|array &$fields Fields used in query, see Database::select
 688          * @param string|array &$conds Conditions used in query, see Database::select
 689          * @param array &$join_conds Join conditions, see Database::select
 690          * @param string|array &$options Options, see Database::select
 691          * @param string|array $filter_tag Tag(s) to select on
 692          *
 693          * @throws MWException When unable to determine appropriate JOIN condition for tagging
 694          */
 695         public static function modifyDisplayQuery( &$tables, &$fields, &$conds,
 696                                                                                 &$join_conds, &$options, $filter_tag = '' ) {
 697                 global $wgUseTagFilter;
 698
 699                 // Normalize to arrays
 700                 $tables = (array)$tables;
 701                 $fields = (array)$fields;
 702                 $conds = (array)$conds;
 703                 $options = (array)$options;
 704
 705                 // Figure out which ID field to use
 706                 if ( in_array( 'recentchanges', $tables ) ) {
 707                         $join_cond = 'ct_rc_id=rc_id';
 708                 } elseif ( in_array( 'logging', $tables ) ) {
 709                         $join_cond = 'ct_log_id=log_id';
 710                 } elseif ( in_array( 'revision', $tables ) ) {
 711                         $join_cond = 'ct_rev_id=rev_id';
 712                 } elseif ( in_array( 'archive', $tables ) ) {
 713                         $join_cond = 'ct_rev_id=ar_rev_id';
 714                 } else {
 715                         throw new MWException( 'Unable to determine appropriate JOIN condition for tagging.' );
 716                 }
 717
 718                 $fields['ts_tags'] = wfGetDB( DB_REPLICA )->buildGroupConcatField(
 719                         ',', 'change_tag', 'ct_tag', $join_cond
 720                 );
 721
 722                 if ( $wgUseTagFilter && $filter_tag ) {
 723                         // Somebody wants to filter on a tag.
 724                         // Add an INNER JOIN on change_tag
 725
 726                         $tables[] = 'change_tag';
 727                         $join_conds['change_tag'] = [ 'INNER JOIN', $join_cond ];
 728                         $conds['ct_tag'] = $filter_tag;
 729                         if (
 730                                 is_array( $filter_tag ) && count( $filter_tag ) > 1 &&
 731                                 !in_array( 'DISTINCT', $options )
 732                         ) {
 733                                 $options[] = 'DISTINCT';
 734                         }
 735                 }
 736         }
 737
 738         /**
 739          * Build a text box to select a change tag
 740          *
 741          * @param string $selected Tag to select by default
 742          * @param bool $ooui Use an OOUI TextInputWidget as selector instead of a non-OOUI input field
 743          *        You need to call OutputPage::enableOOUI() yourself.
 744          * @param IContextSource|null $context
 745          * @note Even though it takes null as a valid argument, an IContextSource is preferred
 746          *       in a new code, as the null value can change in the future
 747          * @return array an array of (label, selector)
 748          */
 749         public static function buildTagFilterSelector(
 750                 $selected = '', $ooui = false, IContextSource $context = null
 751         ) {
 752                 if ( !$context ) {
 753                         $context = RequestContext::getMain();
 754                 }
 755
 756                 $config = $context->getConfig();
 757                 if ( !$config->get( 'UseTagFilter' ) || !count( self::listDefinedTags() ) ) {
 758                         return [];
 759                 }
 760
 761                 $data = [
 762                         Html::rawElement(
 763                                 'label',
 764                                 [ 'for' => 'tagfilter' ],
 765                                 $context->msg( 'tag-filter' )->parse()
 766                         )
 767                 ];
 768
 769                 if ( $ooui ) {
 770                         $data[] = new OOUI\TextInputWidget( [
 771                                 'id' => 'tagfilter',
 772                                 'name' => 'tagfilter',
 773                                 'value' => $selected,
 774                                 'classes' => 'mw-tagfilter-input',
 775                         ] );
 776                 } else {
 777                         $data[] = Xml::input(
 778                                 'tagfilter',
 779                                 20,
 780                                 $selected,
 781                                 [ 'class' => 'mw-tagfilter-input mw-ui-input mw-ui-input-inline', 'id' => 'tagfilter' ]
 782                         );
 783                 }
 784
 785                 return $data;
 786         }
 787
 788         /**
 789          * Defines a tag in the valid_tag table, without checking that the tag name
 790          * is valid.
 791          * Extensions should NOT use this function; they can use the ListDefinedTags
 792          * hook instead.
 793          *
 794          * @param string $tag Tag to create
 795          * @since 1.25
 796          */
 797         public static function defineTag( $tag ) {
 798                 $dbw = wfGetDB( DB_MASTER );
 799                 $dbw->replace( 'valid_tag',
 800                         [ 'vt_tag' ],
 801                         [ 'vt_tag' => $tag ],
 802                         __METHOD__ );
 803
 804                 // clear the memcache of defined tags
 805                 self::purgeTagCacheAll();
 806         }
 807
 808         /**
 809          * Removes a tag from the valid_tag table. The tag may remain in use by
 810          * extensions, and may still show up as 'defined' if an extension is setting
 811          * it from the ListDefinedTags hook.
 812          *
 813          * @param string $tag Tag to remove
 814          * @since 1.25
 815          */
 816         public static function undefineTag( $tag ) {
 817                 $dbw = wfGetDB( DB_MASTER );
 818                 $dbw->delete( 'valid_tag', [ 'vt_tag' => $tag ], __METHOD__ );
 819
 820                 // clear the memcache of defined tags
 821                 self::purgeTagCacheAll();
 822         }
 823
 824         /**
 825          * Writes a tag action into the tag management log.
 826          *
 827          * @param string $action
 828          * @param string $tag
 829          * @param string $reason
 830          * @param User $user Who to attribute the action to
 831          * @param int $tagCount For deletion only, how many usages the tag had before
 832          * it was deleted.
 833          * @param array $logEntryTags Change tags to apply to the entry
 834          * that will be created in the tag management log
 835          * @return int ID of the inserted log entry
 836          * @since 1.25
 837          */
 838         protected static function logTagManagementAction( $action, $tag, $reason,
 839                 User $user, $tagCount = null, array $logEntryTags = []
 840         ) {
 841                 $dbw = wfGetDB( DB_MASTER );
 842
 843                 $logEntry = new ManualLogEntry( 'managetags', $action );
 844                 $logEntry->setPerformer( $user );
 845                 // target page is not relevant, but it has to be set, so we just put in
 846                 // the title of Special:Tags
 847                 $logEntry->setTarget( Title::newFromText( 'Special:Tags' ) );
 848                 $logEntry->setComment( $reason );
 849
 850                 $params = [ '4::tag' => $tag ];
 851                 if ( !is_null( $tagCount ) ) {
 852                         $params['5:number:count'] = $tagCount;
 853                 }
 854                 $logEntry->setParameters( $params );
 855                 $logEntry->setRelations( [ 'Tag' => $tag ] );
 856                 $logEntry->setTags( $logEntryTags );
 857
 858                 $logId = $logEntry->insert( $dbw );
 859                 $logEntry->publish( $logId );
 860                 return $logId;
 861         }
 862
 863         /**
 864          * Is it OK to allow the user to activate this tag?
 865          *
 866          * @param string $tag Tag that you are interested in activating
 867          * @param User|null $user User whose permission you wish to check, or null if
 868          * you don't care (e.g. maintenance scripts)
 869          * @return Status
 870          * @since 1.25
 871          */
 872         public static function canActivateTag( $tag, User $user = null ) {
 873                 if ( !is_null( $user ) ) {
 874                         if ( !$user->isAllowed( 'managechangetags' ) ) {
 875                                 return Status::newFatal( 'tags-manage-no-permission' );
 876                         } elseif ( $user->isBlocked() ) {
 877                                 return Status::newFatal( 'tags-manage-blocked', $user->getName() );
 878                         }
 879                 }
 880
 881                 // defined tags cannot be activated (a defined tag is either extension-
 882                 // defined, in which case the extension chooses whether or not to active it;
 883                 // or user-defined, in which case it is considered active)
 884                 $definedTags = self::listDefinedTags();
 885                 if ( in_array( $tag, $definedTags ) ) {
 886                         return Status::newFatal( 'tags-activate-not-allowed', $tag );
 887                 }
 888
 889                 // non-existing tags cannot be activated
 890                 $tagUsage = self::tagUsageStatistics();
 891                 if ( !isset( $tagUsage[$tag] ) ) { // we already know the tag is undefined
 892                         return Status::newFatal( 'tags-activate-not-found', $tag );
 893                 }
 894
 895                 return Status::newGood();
 896         }
 897
 898         /**
 899          * Activates a tag, checking whether it is allowed first, and adding a log
 900          * entry afterwards.
 901          *
 902          * Includes a call to ChangeTag::canActivateTag(), so your code doesn't need
 903          * to do that.
 904          *
 905          * @param string $tag
 906          * @param string $reason
 907          * @param User $user Who to give credit for the action
 908          * @param bool $ignoreWarnings Can be used for API interaction, default false
 909          * @param array $logEntryTags Change tags to apply to the entry
 910          * that will be created in the tag management log
 911          * @return Status If successful, the Status contains the ID of the added log
 912          * entry as its value
 913          * @since 1.25
 914          */
 915         public static function activateTagWithChecks( $tag, $reason, User $user,
 916                 $ignoreWarnings = false, array $logEntryTags = []
 917         ) {
 918                 // are we allowed to do this?
 919                 $result = self::canActivateTag( $tag, $user );
 920                 if ( $ignoreWarnings ? !$result->isOK() : !$result->isGood() ) {
 921                         $result->value = null;
 922                         return $result;
 923                 }
 924
 925                 // do it!
 926                 self::defineTag( $tag );
 927
 928                 // log it
 929                 $logId = self::logTagManagementAction( 'activate', $tag, $reason, $user,
 930                         null, $logEntryTags );
 931
 932                 return Status::newGood( $logId );
 933         }
 934
 935         /**
 936          * Is it OK to allow the user to deactivate this tag?
 937          *
 938          * @param string $tag Tag that you are interested in deactivating
 939          * @param User|null $user User whose permission you wish to check, or null if
 940          * you don't care (e.g. maintenance scripts)
 941          * @return Status
 942          * @since 1.25
 943          */
 944         public static function canDeactivateTag( $tag, User $user = null ) {
 945                 if ( !is_null( $user ) ) {
 946                         if ( !$user->isAllowed( 'managechangetags' ) ) {
 947                                 return Status::newFatal( 'tags-manage-no-permission' );
 948                         } elseif ( $user->isBlocked() ) {
 949                                 return Status::newFatal( 'tags-manage-blocked', $user->getName() );
 950                         }
 951                 }
 952
 953                 // only explicitly-defined tags can be deactivated
 954                 $explicitlyDefinedTags = self::listExplicitlyDefinedTags();
 955                 if ( !in_array( $tag, $explicitlyDefinedTags ) ) {
 956                         return Status::newFatal( 'tags-deactivate-not-allowed', $tag );
 957                 }
 958                 return Status::newGood();
 959         }
 960
 961         /**
 962          * Deactivates a tag, checking whether it is allowed first, and adding a log
 963          * entry afterwards.
 964          *
 965          * Includes a call to ChangeTag::canDeactivateTag(), so your code doesn't need
 966          * to do that.
 967          *
 968          * @param string $tag
 969          * @param string $reason
 970          * @param User $user Who to give credit for the action
 971          * @param bool $ignoreWarnings Can be used for API interaction, default false
 972          * @param array $logEntryTags Change tags to apply to the entry
 973          * that will be created in the tag management log
 974          * @return Status If successful, the Status contains the ID of the added log
 975          * entry as its value
 976          * @since 1.25
 977          */
 978         public static function deactivateTagWithChecks( $tag, $reason, User $user,
 979                 $ignoreWarnings = false, array $logEntryTags = []
 980         ) {
 981                 // are we allowed to do this?
 982                 $result = self::canDeactivateTag( $tag, $user );
 983                 if ( $ignoreWarnings ? !$result->isOK() : !$result->isGood() ) {
 984                         $result->value = null;
 985                         return $result;
 986                 }
 987
 988                 // do it!
 989                 self::undefineTag( $tag );
 990
 991                 // log it
 992                 $logId = self::logTagManagementAction( 'deactivate', $tag, $reason, $user,
 993                         null, $logEntryTags );
 994
 995                 return Status::newGood( $logId );
 996         }
 997
 998         /**
 999          * Is the tag name valid?
1000          *
1001          * @param string $tag Tag that you are interested in creating
1002          * @return Status
1003          * @since 1.30
1004          */
1005         public static function isTagNameValid( $tag ) {
1006                 // no empty tags
1007                 if ( $tag === '' ) {
1008                         return Status::newFatal( 'tags-create-no-name' );
1009                 }
1010
1011                 // tags cannot contain commas (used as a delimiter in tag_summary table),
1012                 // pipe (used as a delimiter between multiple tags in
1013                 // SpecialRecentchanges and friends), or slashes (would break tag description messages in
1014                 // MediaWiki namespace)
1015                 if ( strpos( $tag, ',' ) !== false || strpos( $tag, '|' ) !== false
1016                         || strpos( $tag, '/' ) !== false ) {
1017                         return Status::newFatal( 'tags-create-invalid-chars' );
1018                 }
1019
1020                 // could the MediaWiki namespace description messages be created?
1021                 $title = Title::makeTitleSafe( NS_MEDIAWIKI, "Tag-$tag-description" );
1022                 if ( is_null( $title ) ) {
1023                         return Status::newFatal( 'tags-create-invalid-title-chars' );
1024                 }
1025
1026                 return Status::newGood();
1027         }
1028
1029         /**
1030          * Is it OK to allow the user to create this tag?
1031          *
1032          * @param string $tag Tag that you are interested in creating
1033          * @param User|null $user User whose permission you wish to check, or null if
1034          * you don't care (e.g. maintenance scripts)
1035          * @return Status
1036          * @since 1.25
1037          */
1038         public static function canCreateTag( $tag, User $user = null ) {
1039                 if ( !is_null( $user ) ) {
1040                         if ( !$user->isAllowed( 'managechangetags' ) ) {
1041                                 return Status::newFatal( 'tags-manage-no-permission' );
1042                         } elseif ( $user->isBlocked() ) {
1043                                 return Status::newFatal( 'tags-manage-blocked', $user->getName() );
1044                         }
1045                 }
1046
1047                 $status = self::isTagNameValid( $tag );
1048                 if ( !$status->isGood() ) {
1049                         return $status;
1050                 }
1051
1052                 // does the tag already exist?
1053                 $tagUsage = self::tagUsageStatistics();
1054                 if ( isset( $tagUsage[$tag] ) || in_array( $tag, self::listDefinedTags() ) ) {
1055                         return Status::newFatal( 'tags-create-already-exists', $tag );
1056                 }
1057
1058                 // check with hooks
1059                 $canCreateResult = Status::newGood();
1060                 Hooks::run( 'ChangeTagCanCreate', [ $tag, $user, &$canCreateResult ] );
1061                 return $canCreateResult;
1062         }
1063
1064         /**
1065          * Creates a tag by adding a row to the `valid_tag` table.
1066          *
1067          * Includes a call to ChangeTag::canDeleteTag(), so your code doesn't need to
1068          * do that.
1069          *
1070          * @param string $tag
1071          * @param string $reason
1072          * @param User $user Who to give credit for the action
1073          * @param bool $ignoreWarnings Can be used for API interaction, default false
1074          * @param array $logEntryTags Change tags to apply to the entry
1075          * that will be created in the tag management log
1076          * @return Status If successful, the Status contains the ID of the added log
1077          * entry as its value
1078          * @since 1.25
1079          */
1080         public static function createTagWithChecks( $tag, $reason, User $user,
1081                 $ignoreWarnings = false, array $logEntryTags = []
1082         ) {
1083                 // are we allowed to do this?
1084                 $result = self::canCreateTag( $tag, $user );
1085                 if ( $ignoreWarnings ? !$result->isOK() : !$result->isGood() ) {
1086                         $result->value = null;
1087                         return $result;
1088                 }
1089
1090                 // do it!
1091                 self::defineTag( $tag );
1092
1093                 // log it
1094                 $logId = self::logTagManagementAction( 'create', $tag, $reason, $user,
1095                         null, $logEntryTags );
1096
1097                 return Status::newGood( $logId );
1098         }
1099
1100         /**
1101          * Permanently removes all traces of a tag from the DB. Good for removing
1102          * misspelt or temporary tags.
1103          *
1104          * This function should be directly called by maintenance scripts only, never
1105          * by user-facing code. See deleteTagWithChecks() for functionality that can
1106          * safely be exposed to users.
1107          *
1108          * @param string $tag Tag to remove
1109          * @return Status The returned status will be good unless a hook changed it
1110          * @since 1.25
1111          */
1112         public static function deleteTagEverywhere( $tag ) {
1113                 $dbw = wfGetDB( DB_MASTER );
1114                 $dbw->startAtomic( __METHOD__ );
1115
1116                 // delete from valid_tag
1117                 self::undefineTag( $tag );
1118
1119                 // find out which revisions use this tag, so we can delete from tag_summary
1120                 $result = $dbw->select( 'change_tag',
1121                         [ 'ct_rc_id', 'ct_log_id', 'ct_rev_id', 'ct_tag' ],
1122                         [ 'ct_tag' => $tag ],
1123                         __METHOD__ );
1124                 foreach ( $result as $row ) {
1125                         // remove the tag from the relevant row of tag_summary
1126                         $tagsToAdd = [];
1127                         $tagsToRemove = [ $tag ];
1128                         self::updateTagSummaryRow( $tagsToAdd, $tagsToRemove, $row->ct_rc_id,
1129                                 $row->ct_rev_id, $row->ct_log_id );
1130                 }
1131
1132                 // delete from change_tag
1133                 $dbw->delete( 'change_tag', [ 'ct_tag' => $tag ], __METHOD__ );
1134
1135                 $dbw->endAtomic( __METHOD__ );
1136
1137                 // give extensions a chance
1138                 $status = Status::newGood();
1139                 Hooks::run( 'ChangeTagAfterDelete', [ $tag, &$status ] );
1140                 // let's not allow error results, as the actual tag deletion succeeded
1141                 if ( !$status->isOK() ) {
1142                         wfDebug( 'ChangeTagAfterDelete error condition downgraded to warning' );
1143                         $status->setOK( true );
1144                 }
1145
1146                 // clear the memcache of defined tags
1147                 self::purgeTagCacheAll();
1148
1149                 return $status;
1150         }
1151
1152         /**
1153          * Is it OK to allow the user to delete this tag?
1154          *
1155          * @param string $tag Tag that you are interested in deleting
1156          * @param User|null $user User whose permission you wish to check, or null if
1157          * you don't care (e.g. maintenance scripts)
1158          * @return Status
1159          * @since 1.25
1160          */
1161         public static function canDeleteTag( $tag, User $user = null ) {
1162                 $tagUsage = self::tagUsageStatistics();
1163
1164                 if ( !is_null( $user ) ) {
1165                         if ( !$user->isAllowed( 'deletechangetags' ) ) {
1166                                 return Status::newFatal( 'tags-delete-no-permission' );
1167                         } elseif ( $user->isBlocked() ) {
1168                                 return Status::newFatal( 'tags-manage-blocked', $user->getName() );
1169                         }
1170                 }
1171
1172                 if ( !isset( $tagUsage[$tag] ) && !in_array( $tag, self::listDefinedTags() ) ) {
1173                         return Status::newFatal( 'tags-delete-not-found', $tag );
1174                 }
1175
1176                 if ( isset( $tagUsage[$tag] ) && $tagUsage[$tag] > self::MAX_DELETE_USES ) {
1177                         return Status::newFatal( 'tags-delete-too-many-uses', $tag, self::MAX_DELETE_USES );
1178                 }
1179
1180                 $softwareDefined = self::listSoftwareDefinedTags();
1181                 if ( in_array( $tag, $softwareDefined ) ) {
1182                         // extension-defined tags can't be deleted unless the extension
1183                         // specifically allows it
1184                         $status = Status::newFatal( 'tags-delete-not-allowed' );
1185                 } else {
1186                         // user-defined tags are deletable unless otherwise specified
1187                         $status = Status::newGood();
1188                 }
1189
1190                 Hooks::run( 'ChangeTagCanDelete', [ $tag, $user, &$status ] );
1191                 return $status;
1192         }
1193
1194         /**
1195          * Deletes a tag, checking whether it is allowed first, and adding a log entry
1196          * afterwards.
1197          *
1198          * Includes a call to ChangeTag::canDeleteTag(), so your code doesn't need to
1199          * do that.
1200          *
1201          * @param string $tag
1202          * @param string $reason
1203          * @param User $user Who to give credit for the action
1204          * @param bool $ignoreWarnings Can be used for API interaction, default false
1205          * @param array $logEntryTags Change tags to apply to the entry
1206          * that will be created in the tag management log
1207          * @return Status If successful, the Status contains the ID of the added log
1208          * entry as its value
1209          * @since 1.25
1210          */
1211         public static function deleteTagWithChecks( $tag, $reason, User $user,
1212                 $ignoreWarnings = false, array $logEntryTags = []
1213         ) {
1214                 // are we allowed to do this?
1215                 $result = self::canDeleteTag( $tag, $user );
1216                 if ( $ignoreWarnings ? !$result->isOK() : !$result->isGood() ) {
1217                         $result->value = null;
1218                         return $result;
1219                 }
1220
1221                 // store the tag usage statistics
1222                 $tagUsage = self::tagUsageStatistics();
1223                 $hitcount = isset( $tagUsage[$tag] ) ? $tagUsage[$tag] : 0;
1224
1225                 // do it!
1226                 $deleteResult = self::deleteTagEverywhere( $tag );
1227                 if ( !$deleteResult->isOK() ) {
1228                         return $deleteResult;
1229                 }
1230
1231                 // log it
1232                 $logId = self::logTagManagementAction( 'delete', $tag, $reason, $user,
1233                         $hitcount, $logEntryTags );
1234
1235                 $deleteResult->value = $logId;
1236                 return $deleteResult;
1237         }
1238
1239         /**
1240          * Lists those tags which core or extensions report as being "active".
1241          *
1242          * @return array
1243          * @since 1.25
1244          */
1245         public static function listSoftwareActivatedTags() {
1246                 // core active tags
1247                 $tags = self::getSoftwareTags();
1248                 if ( !Hooks::isRegistered( 'ChangeTagsListActive' ) ) {
1249                         return $tags;
1250                 }
1251                 $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
1252                 return $cache->getWithSetCallback(
1253                         $cache->makeKey( 'active-tags' ),
1254                         WANObjectCache::TTL_MINUTE * 5,
1255                         function ( $oldValue, &$ttl, array &$setOpts ) use ( $tags ) {
1256                                 $setOpts += Database::getCacheSetOptions( wfGetDB( DB_REPLICA ) );
1257
1258                                 // Ask extensions which tags they consider active
1259                                 Hooks::run( 'ChangeTagsListActive', [ &$tags ] );
1260                                 return $tags;
1261                         },
1262                         [
1263                                 'checkKeys' => [ $cache->makeKey( 'active-tags' ) ],
1264                                 'lockTSE' => WANObjectCache::TTL_MINUTE * 5,
1265                                 'pcTTL' => WANObjectCache::TTL_PROC_LONG
1266                         ]
1267                 );
1268         }
1269
1270         /**
1271          * @see listSoftwareActivatedTags
1272          * @deprecated since 1.28 call listSoftwareActivatedTags directly
1273          * @return array
1274          */
1275         public static function listExtensionActivatedTags() {
1276                 wfDeprecated( __METHOD__, '1.28' );
1277                 return self::listSoftwareActivatedTags();
1278         }
1279
1280         /**
1281          * Basically lists defined tags which count even if they aren't applied to anything.
1282          * It returns a union of the results of listExplicitlyDefinedTags() and
1283          * listExtensionDefinedTags().
1284          *
1285          * @return string[] Array of strings: tags
1286          */
1287         public static function listDefinedTags() {
1288                 $tags1 = self::listExplicitlyDefinedTags();
1289                 $tags2 = self::listSoftwareDefinedTags();
1290                 return array_values( array_unique( array_merge( $tags1, $tags2 ) ) );
1291         }
1292
1293         /**
1294          * Lists tags explicitly defined in the `valid_tag` table of the database.
1295          * Tags in table 'change_tag' which are not in table 'valid_tag' are not
1296          * included.
1297          *
1298          * Tries memcached first.
1299          *
1300          * @return string[] Array of strings: tags
1301          * @since 1.25
1302          */
1303         public static function listExplicitlyDefinedTags() {
1304                 $fname = __METHOD__;
1305
1306                 $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
1307                 return $cache->getWithSetCallback(
1308                         $cache->makeKey( 'valid-tags-db' ),
1309                         WANObjectCache::TTL_MINUTE * 5,
1310                         function ( $oldValue, &$ttl, array &$setOpts ) use ( $fname ) {
1311                                 $dbr = wfGetDB( DB_REPLICA );
1312
1313                                 $setOpts += Database::getCacheSetOptions( $dbr );
1314
1315                                 $tags = $dbr->selectFieldValues( 'valid_tag', 'vt_tag', [], $fname );
1316
1317                                 return array_filter( array_unique( $tags ) );
1318                         },
1319                         [
1320                                 'checkKeys' => [ $cache->makeKey( 'valid-tags-db' ) ],
1321                                 'lockTSE' => WANObjectCache::TTL_MINUTE * 5,
1322                                 'pcTTL' => WANObjectCache::TTL_PROC_LONG
1323                         ]
1324                 );
1325         }
1326
1327         /**
1328          * Lists tags defined by core or extensions using the ListDefinedTags hook.
1329          * Extensions need only define those tags they deem to be in active use.
1330          *
1331          * Tries memcached first.
1332          *
1333          * @return string[] Array of strings: tags
1334          * @since 1.25
1335          */
1336         public static function listSoftwareDefinedTags() {
1337                 // core defined tags
1338                 $tags = self::getSoftwareTags( true );
1339                 if ( !Hooks::isRegistered( 'ListDefinedTags' ) ) {
1340                         return $tags;
1341                 }
1342                 $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
1343                 return $cache->getWithSetCallback(
1344                         $cache->makeKey( 'valid-tags-hook' ),
1345                         WANObjectCache::TTL_MINUTE * 5,
1346                         function ( $oldValue, &$ttl, array &$setOpts ) use ( $tags ) {
1347                                 $setOpts += Database::getCacheSetOptions( wfGetDB( DB_REPLICA ) );
1348
1349                                 Hooks::run( 'ListDefinedTags', [ &$tags ] );
1350                                 return array_filter( array_unique( $tags ) );
1351                         },
1352                         [
1353                                 'checkKeys' => [ $cache->makeKey( 'valid-tags-hook' ) ],
1354                                 'lockTSE' => WANObjectCache::TTL_MINUTE * 5,
1355                                 'pcTTL' => WANObjectCache::TTL_PROC_LONG
1356                         ]
1357                 );
1358         }
1359
1360         /**
1361          * Call listSoftwareDefinedTags directly
1362          *
1363          * @see listSoftwareDefinedTags
1364          * @deprecated since 1.28
1365          * @return array
1366          */
1367         public static function listExtensionDefinedTags() {
1368                 wfDeprecated( __METHOD__, '1.28' );
1369                 return self::listSoftwareDefinedTags();
1370         }
1371
1372         /**
1373          * Invalidates the short-term cache of defined tags used by the
1374          * list*DefinedTags functions, as well as the tag statistics cache.
1375          * @since 1.25
1376          */
1377         public static function purgeTagCacheAll() {
1378                 $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
1379
1380                 $cache->touchCheckKey( $cache->makeKey( 'active-tags' ) );
1381                 $cache->touchCheckKey( $cache->makeKey( 'valid-tags-db' ) );
1382                 $cache->touchCheckKey( $cache->makeKey( 'valid-tags-hook' ) );
1383
1384                 self::purgeTagUsageCache();
1385         }
1386
1387         /**
1388          * Invalidates the tag statistics cache only.
1389          * @since 1.25
1390          */
1391         public static function purgeTagUsageCache() {
1392                 $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
1393
1394                 $cache->touchCheckKey( $cache->makeKey( 'change-tag-statistics' ) );
1395         }
1396
1397         /**
1398          * Returns a map of any tags used on the wiki to number of edits
1399          * tagged with them, ordered descending by the hitcount.
1400          * This does not include tags defined somewhere that have never been applied.
1401          *
1402          * Keeps a short-term cache in memory, so calling this multiple times in the
1403          * same request should be fine.
1404          *
1405          * @return array Array of string => int
1406          */
1407         public static function tagUsageStatistics() {
1408                 $fname = __METHOD__;
1409                 $cache = MediaWikiServices::getInstance()->getMainWANObjectCache();
1410                 return $cache->getWithSetCallback(
1411                         $cache->makeKey( 'change-tag-statistics' ),
1412                         WANObjectCache::TTL_MINUTE * 5,
1413                         function ( $oldValue, &$ttl, array &$setOpts ) use ( $fname ) {
1414                                 $dbr = wfGetDB( DB_REPLICA, 'vslow' );
1415
1416                                 $setOpts += Database::getCacheSetOptions( $dbr );
1417
1418                                 $res = $dbr->select(
1419                                         'change_tag',
1420                                         [ 'ct_tag', 'hitcount' => 'count(*)' ],
1421                                         [],
1422                                         $fname,
1423                                         [ 'GROUP BY' => 'ct_tag', 'ORDER BY' => 'hitcount DESC' ]
1424                                 );
1425
1426                                 $out = [];
1427                                 foreach ( $res as $row ) {
1428                                         $out[$row->ct_tag] = $row->hitcount;
1429                                 }
1430
1431                                 return $out;
1432                         },
1433                         [
1434                                 'checkKeys' => [ $cache->makeKey( 'change-tag-statistics' ) ],
1435                                 'lockTSE' => WANObjectCache::TTL_MINUTE * 5,
1436                                 'pcTTL' => WANObjectCache::TTL_PROC_LONG
1437                         ]
1438                 );
1439         }
1440
1441         /**
1442          * Indicate whether change tag editing UI is relevant
1443          *
1444          * Returns true if the user has the necessary right and there are any
1445          * editable tags defined.
1446          *
1447          * This intentionally doesn't check "any addable || any deletable", because
1448          * it seems like it would be more confusing than useful if the checkboxes
1449          * suddenly showed up because some abuse filter stopped defining a tag and
1450          * then suddenly disappeared when someone deleted all uses of that tag.
1451          *
1452          * @param User $user
1453          * @return bool
1454          */
1455         public static function showTagEditingUI( User $user ) {
1456                 return $user->isAllowed( 'changetags' ) && (bool)self::listExplicitlyDefinedTags();
1457         }
1458 }