includes/Pager.php

   1 <?php
   2 /**
   3  * @defgroup Pager Pager
   4  *
   5  * @file
   6  * @ingroup Pager
   7  */
   8
   9 /**
  10  * Basic pager interface.
  11  * @ingroup Pager
  12  */
  13 interface Pager {
  14         function getNavigationBar();
  15         function getBody();
  16 }
  17
  18 /**
  19  * IndexPager is an efficient pager which uses a (roughly unique) index in the
  20  * data set to implement paging, rather than a "LIMIT offset,limit" clause.
  21  * In MySQL, such a limit/offset clause requires counting through the
  22  * specified number of offset rows to find the desired data, which can be
  23  * expensive for large offsets.
  24  *
  25  * ReverseChronologicalPager is a child class of the abstract IndexPager, and
  26  * contains  some formatting and display code which is specific to the use of
  27  * timestamps as  indexes. Here is a synopsis of its operation:
  28  *
  29  *    * The query is specified by the offset, limit and direction (dir)
  30  *      parameters, in addition to any subclass-specific parameters.
  31  *    * The offset is the non-inclusive start of the DB query. A row with an
  32  *      index value equal to the offset will never be shown.
  33  *    * The query may either be done backwards, where the rows are returned by
  34  *      the database in the opposite order to which they are displayed to the
  35  *      user, or forwards. This is specified by the "dir" parameter, dir=prev
  36  *      means backwards, anything else means forwards. The offset value
  37  *      specifies the start of the database result set, which may be either
  38  *      the start or end of the displayed data set. This allows "previous"
  39  *      links to be implemented without knowledge of the index value at the
  40  *      start of the previous page.
  41  *    * An additional row beyond the user-specified limit is always requested.
  42  *      This allows us to tell whether we should display a "next" link in the
  43  *      case of forwards mode, or a "previous" link in the case of backwards
  44  *      mode. Determining whether to display the other link (the one for the
  45  *      page before the start of the database result set) can be done
  46  *      heuristically by examining the offset.
  47  *
  48  *    * An empty offset indicates that the offset condition should be omitted
  49  *      from the query. This naturally produces either the first page or the
  50  *      last page depending on the dir parameter.
  51  *
  52  *  Subclassing the pager to implement concrete functionality should be fairly
  53  *  simple, please see the examples in HistoryPage.php and
  54  *  SpecialIpblocklist.php. You just need to override formatRow(),
  55  *  getQueryInfo() and getIndexField(). Don't forget to call the parent
  56  *  constructor if you override it.
  57  *
  58  * @ingroup Pager
  59  */
  60 abstract class IndexPager implements Pager {
  61         public $mRequest;
  62         public $mLimitsShown = array( 20, 50, 100, 250, 500 );
  63         public $mDefaultLimit = 50;
  64         public $mOffset, $mLimit;
  65         public $mQueryDone = false;
  66         public $mDb;
  67         public $mPastTheEndRow;
  68
  69         /**
  70          * The index to actually be used for ordering.  This is a single string e-
  71          * ven if multiple orderings are supported.
  72          */
  73         protected $mIndexField;
  74         /** For pages that support multiple types of ordering, which one to use. */
  75         protected $mOrderType;
  76         /**
  77          * $mDefaultDirection gives the direction to use when sorting results:
  78          * false for ascending, true for descending.  If $mIsBackwards is set, we
  79          * start from the opposite end, but we still sort the page itself according
  80          * to $mDefaultDirection.  E.g., if $mDefaultDirection is false but we're
  81          * going backwards, we'll display the last page of results, but the last
  82          * result will be at the bottom, not the top.
  83          *
  84          * Like $mIndexField, $mDefaultDirection will be a single value even if the
  85          * class supports multiple default directions for different order types.
  86          */
  87         public $mDefaultDirection;
  88         public $mIsBackwards;
  89
  90         /** True if the current result set is the first one */
  91         public $mIsFirst;
  92
  93         /**
  94          * Result object for the query. Warning: seek before use.
  95          */
  96         public $mResult;
  97
  98         public function __construct() {
  99                 global $wgRequest, $wgUser;
 100                 $this->mRequest = $wgRequest;
 101
 102                 # NB: the offset is quoted, not validated. It is treated as an
 103                 # arbitrary string to support the widest variety of index types. Be
 104                 # careful outputting it into HTML!
 105                 $this->mOffset = $this->mRequest->getText( 'offset' );
 106
 107                 # Use consistent behavior for the limit options
 108                 $this->mDefaultLimit = intval( $wgUser->getOption( 'rclimit' ) );
 109                 list( $this->mLimit, /* $offset */ ) = $this->mRequest->getLimitOffset();
 110
 111                 $this->mIsBackwards = ( $this->mRequest->getVal( 'dir' ) == 'prev' );
 112                 $this->mDb = wfGetDB( DB_SLAVE );
 113
 114                 $index = $this->getIndexField();
 115                 $order = $this->mRequest->getVal( 'order' );
 116                 if( is_array( $index ) && isset( $index[$order] ) ) {
 117                         $this->mOrderType = $order;
 118                         $this->mIndexField = $index[$order];
 119                 } elseif( is_array( $index ) ) {
 120                         # First element is the default
 121                         reset( $index );
 122                         list( $this->mOrderType, $this->mIndexField ) = each( $index );
 123                 } else {
 124                         # $index is not an array
 125                         $this->mOrderType = null;
 126                         $this->mIndexField = $index;
 127                 }
 128
 129                 if( !isset( $this->mDefaultDirection ) ) {
 130                         $dir = $this->getDefaultDirections();
 131                         $this->mDefaultDirection = is_array( $dir )
 132                                 ? $dir[$this->mOrderType]
 133                                 : $dir;
 134                 }
 135         }
 136
 137         /**
 138          * Do the query, using information from the object context. This function
 139          * has been kept minimal to make it overridable if necessary, to allow for
 140          * result sets formed from multiple DB queries.
 141          */
 142         function doQuery() {
 143                 # Use the child class name for profiling
 144                 $fname = __METHOD__ . ' (' . get_class( $this ) . ')';
 145                 wfProfileIn( $fname );
 146
 147                 $descending = ( $this->mIsBackwards == $this->mDefaultDirection );
 148                 # Plus an extra row so that we can tell the "next" link should be shown
 149                 $queryLimit = $this->mLimit + 1;
 150
 151                 $this->mResult = $this->reallyDoQuery( $this->mOffset, $queryLimit, $descending );
 152                 $this->extractResultInfo( $this->mOffset, $queryLimit, $this->mResult );
 153                 $this->mQueryDone = true;
 154
 155                 $this->preprocessResults( $this->mResult );
 156                 $this->mResult->rewind(); // Paranoia
 157
 158                 wfProfileOut( $fname );
 159         }
 160
 161         /**
 162          * Return the result wrapper.
 163          */
 164         function getResult() {
 165                 return $this->mResult;
 166         }
 167
 168         /**
 169          * Set the offset from an other source than $wgRequest
 170          */
 171         function setOffset( $offset ) {
 172                 $this->mOffset = $offset;
 173         }
 174         /**
 175          * Set the limit from an other source than $wgRequest
 176          */
 177         function setLimit( $limit ) {
 178                 $this->mLimit = $limit;
 179         }
 180
 181         /**
 182          * Extract some useful data from the result object for use by
 183          * the navigation bar, put it into $this
 184          */
 185         function extractResultInfo( $offset, $limit, ResultWrapper $res ) {
 186                 $numRows = $res->numRows();
 187                 if ( $numRows ) {
 188                         $row = $res->fetchRow();
 189                         $firstIndex = $row[$this->mIndexField];
 190
 191                         # Discard the extra result row if there is one
 192                         if ( $numRows > $this->mLimit && $numRows > 1 ) {
 193                                 $res->seek( $numRows - 1 );
 194                                 $this->mPastTheEndRow = $res->fetchObject();
 195                                 $indexField = $this->mIndexField;
 196                                 $this->mPastTheEndIndex = $this->mPastTheEndRow->$indexField;
 197                                 $res->seek( $numRows - 2 );
 198                                 $row = $res->fetchRow();
 199                                 $lastIndex = $row[$this->mIndexField];
 200                         } else {
 201                                 $this->mPastTheEndRow = null;
 202                                 # Setting indexes to an empty string means that they will be
 203                                 # omitted if they would otherwise appear in URLs. It just so
 204                                 # happens that this  is the right thing to do in the standard
 205                                 # UI, in all the relevant cases.
 206                                 $this->mPastTheEndIndex = '';
 207                                 $res->seek( $numRows - 1 );
 208                                 $row = $res->fetchRow();
 209                                 $lastIndex = $row[$this->mIndexField];
 210                         }
 211                 } else {
 212                         $firstIndex = '';
 213                         $lastIndex = '';
 214                         $this->mPastTheEndRow = null;
 215                         $this->mPastTheEndIndex = '';
 216                 }
 217
 218                 if ( $this->mIsBackwards ) {
 219                         $this->mIsFirst = ( $numRows < $limit );
 220                         $this->mIsLast = ( $offset == '' );
 221                         $this->mLastShown = $firstIndex;
 222                         $this->mFirstShown = $lastIndex;
 223                 } else {
 224                         $this->mIsFirst = ( $offset == '' );
 225                         $this->mIsLast = ( $numRows < $limit );
 226                         $this->mLastShown = $lastIndex;
 227                         $this->mFirstShown = $firstIndex;
 228                 }
 229         }
 230
 231         /**
 232          * Do a query with specified parameters, rather than using the object
 233          * context
 234          *
 235          * @param string $offset Index offset, inclusive
 236          * @param integer $limit Exact query limit
 237          * @param boolean $descending Query direction, false for ascending, true for descending
 238          * @return ResultWrapper
 239          */
 240         function reallyDoQuery( $offset, $limit, $descending ) {
 241                 $fname = __METHOD__ . ' (' . get_class( $this ) . ')';
 242                 $info = $this->getQueryInfo();
 243                 $tables = $info['tables'];
 244                 $fields = $info['fields'];
 245                 $conds = isset( $info['conds'] ) ? $info['conds'] : array();
 246                 $options = isset( $info['options'] ) ? $info['options'] : array();
 247                 $join_conds = isset( $info['join_conds'] ) ? $info['join_conds'] : array();
 248                 if ( $descending ) {
 249                         $options['ORDER BY'] = $this->mIndexField;
 250                         $operator = '>';
 251                 } else {
 252                         $options['ORDER BY'] = $this->mIndexField . ' DESC';
 253                         $operator = '<';
 254                 }
 255                 if ( $offset != '' ) {
 256                         $conds[] = $this->mIndexField . $operator . $this->mDb->addQuotes( $offset );
 257                 }
 258                 $options['LIMIT'] = intval( $limit );
 259                 $res = $this->mDb->select( $tables, $fields, $conds, $fname, $options, $join_conds );
 260                 return new ResultWrapper( $this->mDb, $res );
 261         }
 262
 263         /**
 264          * Pre-process results; useful for performing batch existence checks, etc.
 265          *
 266          * @param ResultWrapper $result Result wrapper
 267          */
 268         protected function preprocessResults( $result ) {}
 269
 270         /**
 271          * Get the formatted result list. Calls getStartBody(), formatRow() and
 272          * getEndBody(), concatenates the results and returns them.
 273          */
 274         function getBody() {
 275                 if ( !$this->mQueryDone ) {
 276                         $this->doQuery();
 277                 }
 278                 # Don't use any extra rows returned by the query
 279                 $numRows = min( $this->mResult->numRows(), $this->mLimit );
 280
 281                 $s = $this->getStartBody();
 282                 if ( $numRows ) {
 283                         if ( $this->mIsBackwards ) {
 284                                 for ( $i = $numRows - 1; $i >= 0; $i-- ) {
 285                                         $this->mResult->seek( $i );
 286                                         $row = $this->mResult->fetchObject();
 287                                         $s .= $this->formatRow( $row );
 288                                 }
 289                         } else {
 290                                 $this->mResult->seek( 0 );
 291                                 for ( $i = 0; $i < $numRows; $i++ ) {
 292                                         $row = $this->mResult->fetchObject();
 293                                         $s .= $this->formatRow( $row );
 294                                 }
 295                         }
 296                 } else {
 297                         $s .= $this->getEmptyBody();
 298                 }
 299                 $s .= $this->getEndBody();
 300                 return $s;
 301         }
 302
 303         /**
 304          * Make a self-link
 305          */
 306         function makeLink($text, $query = null, $type=null) {
 307                 if ( $query === null ) {
 308                         return $text;
 309                 }
 310
 311                 $attrs = array();
 312                 if( in_array( $type, array( 'first', 'prev', 'next', 'last' ) ) ) {
 313                         # HTML5 rel attributes
 314                         $attrs['rel'] = $type;
 315                 }
 316
 317                 if( $type ) {
 318                         $attrs['class'] = "mw-{$type}link";
 319                 }
 320                 return $this->getSkin()->link( $this->getTitle(), $text,
 321                         $attrs, $query + $this->getDefaultQuery(), array('noclasses','known') );
 322         }
 323
 324         /**
 325          * Hook into getBody(), allows text to be inserted at the start. This
 326          * will be called even if there are no rows in the result set.
 327          */
 328         function getStartBody() {
 329                 return '';
 330         }
 331
 332         /**
 333          * Hook into getBody() for the end of the list
 334          */
 335         function getEndBody() {
 336                 return '';
 337         }
 338
 339         /**
 340          * Hook into getBody(), for the bit between the start and the
 341          * end when there are no rows
 342          */
 343         function getEmptyBody() {
 344                 return '';
 345         }
 346
 347         /**
 348          * Title used for self-links. Override this if you want to be able to
 349          * use a title other than $wgTitle
 350          */
 351         function getTitle() {
 352                 return $GLOBALS['wgTitle'];
 353         }
 354
 355         /**
 356          * Get the current skin. This can be overridden if necessary.
 357          */
 358         function getSkin() {
 359                 if ( !isset( $this->mSkin ) ) {
 360                         global $wgUser;
 361                         $this->mSkin = $wgUser->getSkin();
 362                 }
 363                 return $this->mSkin;
 364         }
 365
 366         /**
 367          * Get an array of query parameters that should be put into self-links.
 368          * By default, all parameters passed in the URL are used, except for a
 369          * short blacklist.
 370          */
 371         function getDefaultQuery() {
 372                 if ( !isset( $this->mDefaultQuery ) ) {
 373                         $this->mDefaultQuery = $_GET;
 374                         unset( $this->mDefaultQuery['title'] );
 375                         unset( $this->mDefaultQuery['dir'] );
 376                         unset( $this->mDefaultQuery['offset'] );
 377                         unset( $this->mDefaultQuery['limit'] );
 378                         unset( $this->mDefaultQuery['order'] );
 379                         unset( $this->mDefaultQuery['month'] );
 380                         unset( $this->mDefaultQuery['year'] );
 381                 }
 382                 return $this->mDefaultQuery;
 383         }
 384
 385         /**
 386          * Get the number of rows in the result set
 387          */
 388         function getNumRows() {
 389                 if ( !$this->mQueryDone ) {
 390                         $this->doQuery();
 391                 }
 392                 return $this->mResult->numRows();
 393         }
 394
 395         /**
 396          * Get a URL query array for the prev, next, first and last links.
 397          */
 398         function getPagingQueries() {
 399                 if ( !$this->mQueryDone ) {
 400                         $this->doQuery();
 401                 }
 402
 403                 # Don't announce the limit everywhere if it's the default
 404                 $urlLimit = $this->mLimit == $this->mDefaultLimit ? '' : $this->mLimit;
 405
 406                 if ( $this->mIsFirst ) {
 407                         $prev = false;
 408                         $first = false;
 409                 } else {
 410                         $prev = array( 'dir' => 'prev', 'offset' => $this->mFirstShown, 'limit' => $urlLimit );
 411                         $first = array( 'limit' => $urlLimit );
 412                 }
 413                 if ( $this->mIsLast ) {
 414                         $next = false;
 415                         $last = false;
 416                 } else {
 417                         $next = array( 'offset' => $this->mLastShown, 'limit' => $urlLimit );
 418                         $last = array( 'dir' => 'prev', 'limit' => $urlLimit );
 419                 }
 420                 return array( 'prev' => $prev, 'next' => $next, 'first' => $first, 'last' => $last );
 421         }
 422
 423         function isNavigationBarShown() {
 424                 if ( !$this->mQueryDone ) {
 425                         $this->doQuery();
 426                 }
 427                 // Hide navigation by default if there is nothing to page
 428                 return !($this->mIsFirst && $this->mIsLast);
 429         }
 430
 431         /**
 432          * Get paging links. If a link is disabled, the item from $disabledTexts
 433          * will be used. If there is no such item, the unlinked text from
 434          * $linkTexts will be used. Both $linkTexts and $disabledTexts are arrays
 435          * of HTML.
 436          */
 437         function getPagingLinks( $linkTexts, $disabledTexts = array() ) {
 438                 $queries = $this->getPagingQueries();
 439                 $links = array();
 440                 foreach ( $queries as $type => $query ) {
 441                         if ( $query !== false ) {
 442                                 $links[$type] = $this->makeLink( $linkTexts[$type], $queries[$type], $type );
 443                         } elseif ( isset( $disabledTexts[$type] ) ) {
 444                                 $links[$type] = $disabledTexts[$type];
 445                         } else {
 446                                 $links[$type] = $linkTexts[$type];
 447                         }
 448                 }
 449                 return $links;
 450         }
 451
 452         function getLimitLinks() {
 453                 global $wgLang;
 454                 $links = array();
 455                 if ( $this->mIsBackwards ) {
 456                         $offset = $this->mPastTheEndIndex;
 457                 } else {
 458                         $offset = $this->mOffset;
 459                 }
 460                 foreach ( $this->mLimitsShown as $limit ) {
 461                         $links[] = $this->makeLink( $wgLang->formatNum( $limit ),
 462                                 array( 'offset' => $offset, 'limit' => $limit ), 'num' );
 463                 }
 464                 return $links;
 465         }
 466
 467         /**
 468          * Abstract formatting function. This should return an HTML string
 469          * representing the result row $row. Rows will be concatenated and
 470          * returned by getBody()
 471          */
 472         abstract function formatRow( $row );
 473
 474         /**
 475          * This function should be overridden to provide all parameters
 476          * needed for the main paged query. It returns an associative
 477          * array with the following elements:
 478          *    tables => Table(s) for passing to Database::select()
 479          *    fields => Field(s) for passing to Database::select(), may be *
 480          *    conds => WHERE conditions
 481          *    options => option array
 482          *    join_conds => JOIN conditions
 483          */
 484         abstract function getQueryInfo();
 485
 486         /**
 487          * This function should be overridden to return the name of the index fi-
 488          * eld.  If the pager supports multiple orders, it may return an array of
 489          * 'querykey' => 'indexfield' pairs, so that a request with &count=querykey
 490          * will use indexfield to sort.  In this case, the first returned key is
 491          * the default.
 492          *
 493          * Needless to say, it's really not a good idea to use a non-unique index
 494          * for this!  That won't page right.
 495          */
 496         abstract function getIndexField();
 497
 498         /**
 499          * Return the default sorting direction: false for ascending, true for de-
 500          * scending.  You can also have an associative array of ordertype => dir,
 501          * if multiple order types are supported.  In this case getIndexField()
 502          * must return an array, and the keys of that must exactly match the keys
 503          * of this.
 504          *
 505          * For backward compatibility, this method's return value will be ignored
 506          * if $this->mDefaultDirection is already set when the constructor is
 507          * called, for instance if it's statically initialized.  In that case the
 508          * value of that variable (which must be a boolean) will be used.
 509          *
 510          * Note that despite its name, this does not return the value of the
 511          * $this->mDefaultDirection member variable.  That's the default for this
 512          * particular instantiation, which is a single value.  This is the set of
 513          * all defaults for the class.
 514          */
 515         protected function getDefaultDirections() { return false; }
 516 }
 517
 518
 519 /**
 520  * IndexPager with an alphabetic list and a formatted navigation bar
 521  * @ingroup Pager
 522  */
 523 abstract class AlphabeticPager extends IndexPager {
 524         /**
 525          * Shamelessly stolen bits from ReverseChronologicalPager,
 526          * didn't want to do class magic as may be still revamped
 527          */
 528         function getNavigationBar() {
 529                 global $wgLang;
 530
 531                 if ( !$this->isNavigationBarShown() ) return '';
 532
 533                 if( isset( $this->mNavigationBar ) ) {
 534                         return $this->mNavigationBar;
 535                 }
 536
 537                 $opts = array( 'parsemag', 'escapenoentities' );
 538                 $linkTexts = array(
 539                         'prev' => wfMsgExt( 'prevn', $opts, $wgLang->formatNum( $this->mLimit ) ),
 540                         'next' => wfMsgExt( 'nextn', $opts, $wgLang->formatNum($this->mLimit ) ),
 541                         'first' => wfMsgExt( 'page_first', $opts ),
 542                         'last' => wfMsgExt( 'page_last', $opts )
 543                 );
 544
 545                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 546                 $limitLinks = $this->getLimitLinks();
 547                 $limits = $wgLang->pipeList( $limitLinks );
 548
 549                 $this->mNavigationBar =
 550                         "(" . $wgLang->pipeList( array( $pagingLinks['first'], $pagingLinks['last'] ) ) . ") " .
 551                         wfMsgHtml( 'viewprevnext', $pagingLinks['prev'],
 552                         $pagingLinks['next'], $limits );
 553
 554                 if( !is_array( $this->getIndexField() ) ) {
 555                         # Early return to avoid undue nesting
 556                         return $this->mNavigationBar;
 557                 }
 558
 559                 $extra = '';
 560                 $first = true;
 561                 $msgs = $this->getOrderTypeMessages();
 562                 foreach( array_keys( $msgs ) as $order ) {
 563                         if( $first ) {
 564                                 $first = false;
 565                         } else {
 566                                 $extra .= wfMsgExt( 'pipe-separator' , 'escapenoentities' );
 567                         }
 568
 569                         if( $order == $this->mOrderType ) {
 570                                 $extra .= wfMsgHTML( $msgs[$order] );
 571                         } else {
 572                                 $extra .= $this->makeLink(
 573                                         wfMsgHTML( $msgs[$order] ),
 574                                         array( 'order' => $order )
 575                                 );
 576                         }
 577                 }
 578
 579                 if( $extra !== '' ) {
 580                         $this->mNavigationBar .= " ($extra)";
 581                 }
 582
 583                 return $this->mNavigationBar;
 584         }
 585
 586         /**
 587          * If this supports multiple order type messages, give the message key for
 588          * enabling each one in getNavigationBar.  The return type is an associa-
 589          * tive array whose keys must exactly match the keys of the array returned
 590          * by getIndexField(), and whose values are message keys.
 591          * @return array
 592          */
 593         protected function getOrderTypeMessages() {
 594                 return null;
 595         }
 596 }
 597
 598 /**
 599  * IndexPager with a formatted navigation bar
 600  * @ingroup Pager
 601  */
 602 abstract class ReverseChronologicalPager extends IndexPager {
 603         public $mDefaultDirection = true;
 604         public $mYear;
 605         public $mMonth;
 606
 607         function __construct() {
 608                 parent::__construct();
 609         }
 610
 611         function getNavigationBar() {
 612                 global $wgLang;
 613
 614                 if ( !$this->isNavigationBarShown() ) return '';
 615
 616                 if ( isset( $this->mNavigationBar ) ) {
 617                         return $this->mNavigationBar;
 618                 }
 619                 $nicenumber = $wgLang->formatNum( $this->mLimit );
 620                 $linkTexts = array(
 621                         'prev' => wfMsgExt( 'pager-newer-n', array( 'parsemag', 'escape' ), $nicenumber ),
 622                         'next' => wfMsgExt( 'pager-older-n', array( 'parsemag', 'escape' ), $nicenumber ),
 623                         'first' => wfMsgHtml( 'histlast' ),
 624                         'last' => wfMsgHtml( 'histfirst' )
 625                 );
 626
 627                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 628                 $limitLinks = $this->getLimitLinks();
 629                 $limits = $wgLang->pipeList( $limitLinks );
 630
 631                 $this->mNavigationBar = "({$pagingLinks['first']}" . wfMsgExt( 'pipe-separator' , 'escapenoentities' ) . "{$pagingLinks['last']}) " .
 632                         wfMsgHtml("viewprevnext", $pagingLinks['prev'], $pagingLinks['next'], $limits);
 633                 return $this->mNavigationBar;
 634         }
 635
 636         function getDateCond( $year, $month ) {
 637                 $year = intval($year);
 638                 $month = intval($month);
 639                 // Basic validity checks
 640                 $this->mYear = $year > 0 ? $year : false;
 641                 $this->mMonth = ($month > 0 && $month < 13) ? $month : false;
 642                 // Given an optional year and month, we need to generate a timestamp
 643                 // to use as "WHERE rev_timestamp <= result"
 644                 // Examples: year = 2006 equals < 20070101 (+000000)
 645                 // year=2005, month=1    equals < 20050201
 646                 // year=2005, month=12   equals < 20060101
 647                 if ( !$this->mYear && !$this->mMonth ) {
 648                         return;
 649                 }
 650                 if ( $this->mYear ) {
 651                         $year = $this->mYear;
 652                 } else {
 653                         // If no year given, assume the current one
 654                         $year = gmdate( 'Y' );
 655                         // If this month hasn't happened yet this year, go back to last year's month
 656                         if( $this->mMonth > gmdate( 'n' ) ) {
 657                                 $year--;
 658                         }
 659                 }
 660                 if ( $this->mMonth ) {
 661                         $month = $this->mMonth + 1;
 662                         // For December, we want January 1 of the next year
 663                         if ($month > 12) {
 664                                 $month = 1;
 665                                 $year++;
 666                         }
 667                 } else {
 668                         // No month implies we want up to the end of the year in question
 669                         $month = 1;
 670                         $year++;
 671                 }
 672                 // Y2K38 bug
 673                 if ( $year > 2032 ) {
 674                         $year = 2032;
 675                 }
 676                 $ymd = (int)sprintf( "%04d%02d01", $year, $month );
 677                 if ( $ymd > 20320101 ) {
 678                         $ymd = 20320101;
 679                 }
 680                 $this->mOffset = $this->mDb->timestamp( "${ymd}000000" );
 681         }
 682 }
 683
 684 /**
 685  * Table-based display with a user-selectable sort order
 686  * @ingroup Pager
 687  */
 688 abstract class TablePager extends IndexPager {
 689         var $mSort;
 690         var $mCurrentRow;
 691
 692         function __construct() {
 693                 global $wgRequest;
 694                 $this->mSort = $wgRequest->getText( 'sort' );
 695                 if ( !array_key_exists( $this->mSort, $this->getFieldNames() ) ) {
 696                         $this->mSort = $this->getDefaultSort();
 697                 }
 698                 if ( $wgRequest->getBool( 'asc' ) ) {
 699                         $this->mDefaultDirection = false;
 700                 } elseif ( $wgRequest->getBool( 'desc' ) ) {
 701                         $this->mDefaultDirection = true;
 702                 } /* Else leave it at whatever the class default is */
 703
 704                 parent::__construct();
 705         }
 706
 707         function getStartBody() {
 708                 global $wgStylePath;
 709                 $tableClass = htmlspecialchars( $this->getTableClass() );
 710                 $sortClass = htmlspecialchars( $this->getSortHeaderClass() );
 711
 712                 $s = "<table border='1' class=\"$tableClass\"><thead><tr>\n";
 713                 $fields = $this->getFieldNames();
 714
 715                 # Make table header
 716                 foreach ( $fields as $field => $name ) {
 717                         if ( strval( $name ) == '' ) {
 718                                 $s .= "<th>&nbsp;</th>\n";
 719                         } elseif ( $this->isFieldSortable( $field ) ) {
 720                                 $query = array( 'sort' => $field, 'limit' => $this->mLimit );
 721                                 if ( $field == $this->mSort ) {
 722                                         # This is the sorted column
 723                                         # Prepare a link that goes in the other sort order
 724                                         if ( $this->mDefaultDirection ) {
 725                                                 # Descending
 726                                                 $image = 'Arr_u.png';
 727                                                 $query['asc'] = '1';
 728                                                 $query['desc'] = '';
 729                                                 $alt = htmlspecialchars( wfMsg( 'descending_abbrev' ) );
 730                                         } else {
 731                                                 # Ascending
 732                                                 $image = 'Arr_d.png';
 733                                                 $query['asc'] = '';
 734                                                 $query['desc'] = '1';
 735                                                 $alt = htmlspecialchars( wfMsg( 'ascending_abbrev' ) );
 736                                         }
 737                                         $image = htmlspecialchars( "$wgStylePath/common/images/$image" );
 738                                         $link = $this->makeLink(
 739                                                 "<img width=\"12\" height=\"12\" alt=\"$alt\" src=\"$image\" />" .
 740                                                 htmlspecialchars( $name ), $query );
 741                                         $s .= "<th class=\"$sortClass\">$link</th>\n";
 742                                 } else {
 743                                         $s .= '<th>' . $this->makeLink( htmlspecialchars( $name ), $query ) . "</th>\n";
 744                                 }
 745                         } else {
 746                                 $s .= '<th>' . htmlspecialchars( $name ) . "</th>\n";
 747                         }
 748                 }
 749                 $s .= "</tr></thead><tbody>\n";
 750                 return $s;
 751         }
 752
 753         function getEndBody() {
 754                 return "</tbody></table>\n";
 755         }
 756
 757         function getEmptyBody() {
 758                 $colspan = count( $this->getFieldNames() );
 759                 $msgEmpty = wfMsgHtml( 'table_pager_empty' );
 760                 return "<tr><td colspan=\"$colspan\">$msgEmpty</td></tr>\n";
 761         }
 762
 763         function formatRow( $row ) {
 764                 $this->mCurrentRow = $row;      # In case formatValue etc need to know
 765                 $s = Xml::openElement( 'tr', $this->getRowAttrs($row) );
 766                 $fieldNames = $this->getFieldNames();
 767                 foreach ( $fieldNames as $field => $name ) {
 768                         $value = isset( $row->$field ) ? $row->$field : null;
 769                         $formatted = strval( $this->formatValue( $field, $value ) );
 770                         if ( $formatted == '' ) {
 771                                 $formatted = '&nbsp;';
 772                         }
 773                         $s .= Xml::tags( 'td', $this->getCellAttrs( $field, $value ), $formatted );
 774                 }
 775                 $s .= "</tr>\n";
 776                 return $s;
 777         }
 778
 779         /**
 780          * Get a class name to be applied to the given row.
 781          * @param object $row The database result row
 782          */
 783         function getRowClass( $row ) {
 784                 return '';
 785         }
 786
 787         /**
 788          * Get attributes to be applied to the given row.
 789          * @param object $row The database result row
 790          * @return associative array
 791          */
 792         function getRowAttrs( $row ) {
 793                 return array( 'class' => $this->getRowClass( $row ) );
 794         }
 795
 796         /**
 797          * Get any extra attributes to be applied to the given cell. Don't
 798          * take this as an excuse to hardcode styles; use classes and
 799          * CSS instead.  Row context is available in $this->mCurrentRow
 800          * @param $field The column
 801          * @param $value The cell contents
 802          * @return associative array
 803          */
 804         function getCellAttrs( $field, $value ) {
 805                 return array( 'class' => 'TablePager_col_' . $field );
 806         }
 807
 808         function getIndexField() {
 809                 return $this->mSort;
 810         }
 811
 812         function getTableClass() {
 813                 return 'TablePager';
 814         }
 815
 816         function getNavClass() {
 817                 return 'TablePager_nav';
 818         }
 819
 820         function getSortHeaderClass() {
 821                 return 'TablePager_sort';
 822         }
 823
 824         /**
 825          * A navigation bar with images
 826          */
 827         function getNavigationBar() {
 828                 global $wgStylePath, $wgContLang;
 829
 830                 if ( !$this->isNavigationBarShown() ) return '';
 831
 832                 $path = "$wgStylePath/common/images";
 833                 $labels = array(
 834                         'first' => 'table_pager_first',
 835                         'prev' => 'table_pager_prev',
 836                         'next' => 'table_pager_next',
 837                         'last' => 'table_pager_last',
 838                 );
 839                 $images = array(
 840                         'first' => 'arrow_first_25.png',
 841                         'prev' => 'arrow_left_25.png',
 842                         'next' => 'arrow_right_25.png',
 843                         'last' => 'arrow_last_25.png',
 844                 );
 845                 $disabledImages = array(
 846                         'first' => 'arrow_disabled_first_25.png',
 847                         'prev' => 'arrow_disabled_left_25.png',
 848                         'next' => 'arrow_disabled_right_25.png',
 849                         'last' => 'arrow_disabled_last_25.png',
 850                 );
 851                 if( $wgContLang->isRTL() ) {
 852                         $keys = array_keys( $labels );
 853                         $images = array_combine( $keys, array_reverse( $images ) );
 854                         $disabledImages = array_combine( $keys, array_reverse( $disabledImages ) );
 855                 }
 856
 857                 $linkTexts = array();
 858                 $disabledTexts = array();
 859                 foreach ( $labels as $type => $label ) {
 860                         $msgLabel = wfMsgHtml( $label );
 861                         $linkTexts[$type] = "<img src=\"$path/{$images[$type]}\" alt=\"$msgLabel\"/><br/>$msgLabel";
 862                         $disabledTexts[$type] = "<img src=\"$path/{$disabledImages[$type]}\" alt=\"$msgLabel\"/><br/>$msgLabel";
 863                 }
 864                 $links = $this->getPagingLinks( $linkTexts, $disabledTexts );
 865
 866                 $navClass = htmlspecialchars( $this->getNavClass() );
 867                 $s = "<table class=\"$navClass\" align=\"center\" cellpadding=\"3\"><tr>\n";
 868                 $cellAttrs = 'valign="top" align="center" width="' . 100 / count( $links ) . '%"';
 869                 foreach ( $labels as $type => $label ) {
 870                         $s .= "<td $cellAttrs>{$links[$type]}</td>\n";
 871                 }
 872                 $s .= "</tr></table>\n";
 873                 return $s;
 874         }
 875
 876         /**
 877          * Get a <select> element which has options for each of the allowed limits
 878          */
 879         function getLimitSelect() {
 880                 global $wgLang;
 881                 $s = "<select name=\"limit\">";
 882                 foreach ( $this->mLimitsShown as $key => $value ) {
 883                         # The pair is either $index => $limit, in which case the $value
 884                         # will be numeric, or $limit => $text, in which case the $value
 885                         # will be a string.
 886                         if( is_int( $value ) ){
 887                                 $limit = $value;
 888                                 $text = $wgLang->formatNum( $limit );
 889                         } else {
 890                                 $limit = $key;
 891                                 $text = $value;
 892                         }
 893                         $selected = ( $limit == $this->mLimit ? 'selected="selected"' : '' );
 894                         $s .= "<option value=\"$limit\" $selected>$text</option>\n";
 895                 }
 896                 $s .= "</select>";
 897                 return $s;
 898         }
 899
 900         /**
 901          * Get <input type="hidden"> elements for use in a method="get" form.
 902          * Resubmits all defined elements of the $_GET array, except for a
 903          * blacklist, passed in the $blacklist parameter.
 904          */
 905         function getHiddenFields( $blacklist = array() ) {
 906                 $blacklist = (array)$blacklist;
 907                 $query = $_GET;
 908                 foreach ( $blacklist as $name ) {
 909                         unset( $query[$name] );
 910                 }
 911                 $s = '';
 912                 foreach ( $query as $name => $value ) {
 913                         $encName = htmlspecialchars( $name );
 914                         $encValue = htmlspecialchars( $value );
 915                         $s .= "<input type=\"hidden\" name=\"$encName\" value=\"$encValue\"/>\n";
 916                 }
 917                 return $s;
 918         }
 919
 920         /**
 921          * Get a form containing a limit selection dropdown
 922          */
 923         function getLimitForm() {
 924                 global $wgScript;
 925
 926                 # Make the select with some explanatory text
 927                 $msgSubmit = wfMsgHtml( 'table_pager_limit_submit' );
 928                 return
 929                         Xml::openElement( 'form', array( 'method' => 'get', 'action' => $wgScript ) ) . "\n" .
 930                         wfMsgHtml( 'table_pager_limit', $this->getLimitSelect() ) .
 931                         "\n<input type=\"submit\" value=\"$msgSubmit\"/>\n" .
 932                         $this->getHiddenFields( array( 'limit' ) ) .
 933                         "</form>\n";
 934         }
 935
 936         /**
 937          * Return true if the named field should be sortable by the UI, false
 938          * otherwise
 939          *
 940          * @param string $field
 941          */
 942         abstract function isFieldSortable( $field );
 943
 944         /**
 945          * Format a table cell. The return value should be HTML, but use an empty
 946          * string not &nbsp; for empty cells. Do not include the <td> and </td>.
 947          *
 948          * The current result row is available as $this->mCurrentRow, in case you
 949          * need more context.
 950          *
 951          * @param string $name The database field name
 952          * @param string $value The value retrieved from the database
 953          */
 954         abstract function formatValue( $name, $value );
 955
 956         /**
 957          * The database field name used as a default sort order
 958          */
 959         abstract function getDefaultSort();
 960
 961         /**
 962          * An array mapping database field names to a textual description of the
 963          * field name, for use in the table header. The description should be plain
 964          * text, it will be HTML-escaped later.
 965          */
 966         abstract function getFieldNames();
 967 }