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
  71          * even if multiple orderings are supported.
  72          */
  73         protected $mIndexField;
  74         /** For pages that support multiple types of ordering, which one to use.
  75          */
  76         protected $mOrderType;
  77         /**
  78          * $mDefaultDirection gives the direction to use when sorting results:
  79          * false for ascending, true for descending.  If $mIsBackwards is set, we
  80          * start from the opposite end, but we still sort the page itself according
  81          * to $mDefaultDirection.  E.g., if $mDefaultDirection is false but we're
  82          * going backwards, we'll display the last page of results, but the last
  83          * result will be at the bottom, not the top.
  84          *
  85          * Like $mIndexField, $mDefaultDirection will be a single value even if the
  86          * class supports multiple default directions for different order types.
  87          */
  88         public $mDefaultDirection;
  89         public $mIsBackwards;
  90
  91         /** True if the current result set is the first one */
  92         public $mIsFirst;
  93
  94         /**
  95          * Result object for the query. Warning: seek before use.
  96          */
  97         public $mResult;
  98
  99         public function __construct() {
 100                 global $wgRequest, $wgUser;
 101                 $this->mRequest = $wgRequest;
 102
 103                 # NB: the offset is quoted, not validated. It is treated as an
 104                 # arbitrary string to support the widest variety of index types. Be
 105                 # careful outputting it into HTML!
 106                 $this->mOffset = $this->mRequest->getText( 'offset' );
 107
 108                 # Use consistent behavior for the limit options
 109                 $this->mDefaultLimit = intval( $wgUser->getOption( 'rclimit' ) );
 110                 list( $this->mLimit, /* $offset */ ) = $this->mRequest->getLimitOffset();
 111
 112                 $this->mIsBackwards = ( $this->mRequest->getVal( 'dir' ) == 'prev' );
 113                 $this->mDb = wfGetDB( DB_SLAVE );
 114
 115                 $index = $this->getIndexField();
 116                 $order = $this->mRequest->getVal( 'order' );
 117                 if( is_array( $index ) && isset( $index[$order] ) ) {
 118                         $this->mOrderType = $order;
 119                         $this->mIndexField = $index[$order];
 120                 } elseif( is_array( $index ) ) {
 121                         # First element is the default
 122                         reset( $index );
 123                         list( $this->mOrderType, $this->mIndexField ) = each( $index );
 124                 } else {
 125                         # $index is not an array
 126                         $this->mOrderType = null;
 127                         $this->mIndexField = $index;
 128                 }
 129
 130                 if( !isset( $this->mDefaultDirection ) ) {
 131                         $dir = $this->getDefaultDirections();
 132                         $this->mDefaultDirection = is_array( $dir )
 133                                 ? $dir[$this->mOrderType]
 134                                 : $dir;
 135                 }
 136         }
 137
 138         /**
 139          * Do the query, using information from the object context. This function
 140          * has been kept minimal to make it overridable if necessary, to allow for
 141          * result sets formed from multiple DB queries.
 142          */
 143         function doQuery() {
 144                 # Use the child class name for profiling
 145                 $fname = __METHOD__ . ' (' . get_class( $this ) . ')';
 146                 wfProfileIn( $fname );
 147
 148                 $descending = ( $this->mIsBackwards == $this->mDefaultDirection );
 149                 # Plus an extra row so that we can tell the "next" link should be shown
 150                 $queryLimit = $this->mLimit + 1;
 151
 152                 $this->mResult = $this->reallyDoQuery(
 153                         $this->mOffset,
 154                         $queryLimit,
 155                         $descending
 156                 );
 157                 $this->extractResultInfo( $this->mOffset, $queryLimit, $this->mResult );
 158                 $this->mQueryDone = true;
 159
 160                 $this->preprocessResults( $this->mResult );
 161                 $this->mResult->rewind(); // Paranoia
 162
 163                 wfProfileOut( $fname );
 164         }
 165
 166         /**
 167          * Return the result wrapper.
 168          */
 169         function getResult() {
 170                 return $this->mResult;
 171         }
 172
 173         /**
 174          * Set the offset from an other source than $wgRequest
 175          */
 176         function setOffset( $offset ) {
 177                 $this->mOffset = $offset;
 178         }
 179         /**
 180          * Set the limit from an other source than $wgRequest
 181          */
 182         function setLimit( $limit ) {
 183                 $this->mLimit = $limit;
 184         }
 185
 186         /**
 187          * Extract some useful data from the result object for use by
 188          * the navigation bar, put it into $this
 189          */
 190         function extractResultInfo( $offset, $limit, ResultWrapper $res ) {
 191                 $numRows = $res->numRows();
 192                 if ( $numRows ) {
 193                         $row = $res->fetchRow();
 194                         $firstIndex = $row[$this->mIndexField];
 195
 196                         # Discard the extra result row if there is one
 197                         if ( $numRows > $this->mLimit && $numRows > 1 ) {
 198                                 $res->seek( $numRows - 1 );
 199                                 $this->mPastTheEndRow = $res->fetchObject();
 200                                 $indexField = $this->mIndexField;
 201                                 $this->mPastTheEndIndex = $this->mPastTheEndRow->$indexField;
 202                                 $res->seek( $numRows - 2 );
 203                                 $row = $res->fetchRow();
 204                                 $lastIndex = $row[$this->mIndexField];
 205                         } else {
 206                                 $this->mPastTheEndRow = null;
 207                                 # Setting indexes to an empty string means that they will be
 208                                 # omitted if they would otherwise appear in URLs. It just so
 209                                 # happens that this  is the right thing to do in the standard
 210                                 # UI, in all the relevant cases.
 211                                 $this->mPastTheEndIndex = '';
 212                                 $res->seek( $numRows - 1 );
 213                                 $row = $res->fetchRow();
 214                                 $lastIndex = $row[$this->mIndexField];
 215                         }
 216                 } else {
 217                         $firstIndex = '';
 218                         $lastIndex = '';
 219                         $this->mPastTheEndRow = null;
 220                         $this->mPastTheEndIndex = '';
 221                 }
 222
 223                 if ( $this->mIsBackwards ) {
 224                         $this->mIsFirst = ( $numRows < $limit );
 225                         $this->mIsLast = ( $offset == '' );
 226                         $this->mLastShown = $firstIndex;
 227                         $this->mFirstShown = $lastIndex;
 228                 } else {
 229                         $this->mIsFirst = ( $offset == '' );
 230                         $this->mIsLast = ( $numRows < $limit );
 231                         $this->mLastShown = $lastIndex;
 232                         $this->mFirstShown = $firstIndex;
 233                 }
 234         }
 235
 236         /**
 237          * Get some text to go in brackets in the "function name" part of the SQL comment
 238          */
 239         function getSqlComment() {
 240                 return get_class( $this );
 241         }
 242
 243         /**
 244          * Do a query with specified parameters, rather than using the object
 245          * context
 246          *
 247          * @param string $offset Index offset, inclusive
 248          * @param integer $limit Exact query limit
 249          * @param boolean $descending Query direction, false for ascending, true for descending
 250          * @return ResultWrapper
 251          */
 252         function reallyDoQuery( $offset, $limit, $descending ) {
 253                 $fname = __METHOD__ . ' (' . $this->getSqlComment() . ')';
 254                 $info = $this->getQueryInfo();
 255                 $tables = $info['tables'];
 256                 $fields = $info['fields'];
 257                 $conds = isset( $info['conds'] ) ? $info['conds'] : array();
 258                 $options = isset( $info['options'] ) ? $info['options'] : array();
 259                 $join_conds = isset( $info['join_conds'] ) ? $info['join_conds'] : array();
 260                 if ( $descending ) {
 261                         $options['ORDER BY'] = $this->mIndexField;
 262                         $operator = '>';
 263                 } else {
 264                         $options['ORDER BY'] = $this->mIndexField . ' DESC';
 265                         $operator = '<';
 266                 }
 267                 if ( $offset != '' ) {
 268                         $conds[] = $this->mIndexField . $operator . $this->mDb->addQuotes( $offset );
 269                 }
 270                 $options['LIMIT'] = intval( $limit );
 271                 $res = $this->mDb->select( $tables, $fields, $conds, $fname, $options, $join_conds );
 272                 return new ResultWrapper( $this->mDb, $res );
 273         }
 274
 275         /**
 276          * Pre-process results; useful for performing batch existence checks, etc.
 277          *
 278          * @param ResultWrapper $result Result wrapper
 279          */
 280         protected function preprocessResults( $result ) {}
 281
 282         /**
 283          * Get the formatted result list. Calls getStartBody(), formatRow() and
 284          * getEndBody(), concatenates the results and returns them.
 285          */
 286         function getBody() {
 287                 if ( !$this->mQueryDone ) {
 288                         $this->doQuery();
 289                 }
 290                 # Don't use any extra rows returned by the query
 291                 $numRows = min( $this->mResult->numRows(), $this->mLimit );
 292
 293                 $s = $this->getStartBody();
 294                 if ( $numRows ) {
 295                         if ( $this->mIsBackwards ) {
 296                                 for ( $i = $numRows - 1; $i >= 0; $i-- ) {
 297                                         $this->mResult->seek( $i );
 298                                         $row = $this->mResult->fetchObject();
 299                                         $s .= $this->formatRow( $row );
 300                                 }
 301                         } else {
 302                                 $this->mResult->seek( 0 );
 303                                 for ( $i = 0; $i < $numRows; $i++ ) {
 304                                         $row = $this->mResult->fetchObject();
 305                                         $s .= $this->formatRow( $row );
 306                                 }
 307                         }
 308                 } else {
 309                         $s .= $this->getEmptyBody();
 310                 }
 311                 $s .= $this->getEndBody();
 312                 return $s;
 313         }
 314
 315         /**
 316          * Make a self-link
 317          */
 318         function makeLink($text, $query = null, $type=null) {
 319                 if ( $query === null ) {
 320                         return $text;
 321                 }
 322
 323                 $attrs = array();
 324                 if( in_array( $type, array( 'first', 'prev', 'next', 'last' ) ) ) {
 325                         # HTML5 rel attributes
 326                         $attrs['rel'] = $type;
 327                 }
 328
 329                 if( $type ) {
 330                         $attrs['class'] = "mw-{$type}link";
 331                 }
 332                 return $this->getSkin()->link(
 333                         $this->getTitle(),
 334                         $text,
 335                         $attrs,
 336                         $query + $this->getDefaultQuery(),
 337                         array( 'noclasses', 'known' )
 338                 );
 339         }
 340
 341         /**
 342          * Hook into getBody(), allows text to be inserted at the start. This
 343          * will be called even if there are no rows in the result set.
 344          */
 345         function getStartBody() {
 346                 return '';
 347         }
 348
 349         /**
 350          * Hook into getBody() for the end of the list
 351          */
 352         function getEndBody() {
 353                 return '';
 354         }
 355
 356         /**
 357          * Hook into getBody(), for the bit between the start and the
 358          * end when there are no rows
 359          */
 360         function getEmptyBody() {
 361                 return '';
 362         }
 363
 364         /**
 365          * Title used for self-links. Override this if you want to be able to
 366          * use a title other than $wgTitle
 367          */
 368         function getTitle() {
 369                 return $GLOBALS['wgTitle'];
 370         }
 371
 372         /**
 373          * Get the current skin. This can be overridden if necessary.
 374          */
 375         function getSkin() {
 376                 if ( !isset( $this->mSkin ) ) {
 377                         global $wgUser;
 378                         $this->mSkin = $wgUser->getSkin();
 379                 }
 380                 return $this->mSkin;
 381         }
 382
 383         /**
 384          * Get an array of query parameters that should be put into self-links.
 385          * By default, all parameters passed in the URL are used, except for a
 386          * short blacklist.
 387          */
 388         function getDefaultQuery() {
 389                 if ( !isset( $this->mDefaultQuery ) ) {
 390                         $this->mDefaultQuery = $_GET;
 391                         unset( $this->mDefaultQuery['title'] );
 392                         unset( $this->mDefaultQuery['dir'] );
 393                         unset( $this->mDefaultQuery['offset'] );
 394                         unset( $this->mDefaultQuery['limit'] );
 395                         unset( $this->mDefaultQuery['order'] );
 396                         unset( $this->mDefaultQuery['month'] );
 397                         unset( $this->mDefaultQuery['year'] );
 398                 }
 399                 return $this->mDefaultQuery;
 400         }
 401
 402         /**
 403          * Get the number of rows in the result set
 404          */
 405         function getNumRows() {
 406                 if ( !$this->mQueryDone ) {
 407                         $this->doQuery();
 408                 }
 409                 return $this->mResult->numRows();
 410         }
 411
 412         /**
 413          * Get a URL query array for the prev, next, first and last links.
 414          */
 415         function getPagingQueries() {
 416                 if ( !$this->mQueryDone ) {
 417                         $this->doQuery();
 418                 }
 419
 420                 # Don't announce the limit everywhere if it's the default
 421                 $urlLimit = $this->mLimit == $this->mDefaultLimit ? '' : $this->mLimit;
 422
 423                 if ( $this->mIsFirst ) {
 424                         $prev = false;
 425                         $first = false;
 426                 } else {
 427                         $prev = array(
 428                                 'dir' => 'prev',
 429                                 'offset' => $this->mFirstShown,
 430                                 'limit' => $urlLimit
 431                         );
 432                         $first = array( 'limit' => $urlLimit );
 433                 }
 434                 if ( $this->mIsLast ) {
 435                         $next = false;
 436                         $last = false;
 437                 } else {
 438                         $next = array( 'offset' => $this->mLastShown, 'limit' => $urlLimit );
 439                         $last = array( 'dir' => 'prev', 'limit' => $urlLimit );
 440                 }
 441                 return array(
 442                         'prev' => $prev,
 443                         'next' => $next,
 444                         'first' => $first,
 445                         'last' => $last
 446                 );
 447         }
 448
 449         function isNavigationBarShown() {
 450                 if ( !$this->mQueryDone ) {
 451                         $this->doQuery();
 452                 }
 453                 // Hide navigation by default if there is nothing to page
 454                 return !($this->mIsFirst && $this->mIsLast);
 455         }
 456
 457         /**
 458          * Get paging links. If a link is disabled, the item from $disabledTexts
 459          * will be used. If there is no such item, the unlinked text from
 460          * $linkTexts will be used. Both $linkTexts and $disabledTexts are arrays
 461          * of HTML.
 462          */
 463         function getPagingLinks( $linkTexts, $disabledTexts = array() ) {
 464                 $queries = $this->getPagingQueries();
 465                 $links = array();
 466                 foreach ( $queries as $type => $query ) {
 467                         if ( $query !== false ) {
 468                                 $links[$type] = $this->makeLink(
 469                                         $linkTexts[$type],
 470                                         $queries[$type],
 471                                         $type
 472                                 );
 473                         } elseif ( isset( $disabledTexts[$type] ) ) {
 474                                 $links[$type] = $disabledTexts[$type];
 475                         } else {
 476                                 $links[$type] = $linkTexts[$type];
 477                         }
 478                 }
 479                 return $links;
 480         }
 481
 482         function getLimitLinks() {
 483                 global $wgLang;
 484                 $links = array();
 485                 if ( $this->mIsBackwards ) {
 486                         $offset = $this->mPastTheEndIndex;
 487                 } else {
 488                         $offset = $this->mOffset;
 489                 }
 490                 foreach ( $this->mLimitsShown as $limit ) {
 491                         $links[] = $this->makeLink(
 492                                 $wgLang->formatNum( $limit ),
 493                                 array( 'offset' => $offset, 'limit' => $limit ),
 494                                 'num'
 495                         );
 496                 }
 497                 return $links;
 498         }
 499
 500         /**
 501          * Abstract formatting function. This should return an HTML string
 502          * representing the result row $row. Rows will be concatenated and
 503          * returned by getBody()
 504          */
 505         abstract function formatRow( $row );
 506
 507         /**
 508          * This function should be overridden to provide all parameters
 509          * needed for the main paged query. It returns an associative
 510          * array with the following elements:
 511          *    tables => Table(s) for passing to Database::select()
 512          *    fields => Field(s) for passing to Database::select(), may be *
 513          *    conds => WHERE conditions
 514          *    options => option array
 515          *    join_conds => JOIN conditions
 516          */
 517         abstract function getQueryInfo();
 518
 519         /**
 520          * This function should be overridden to return the name of the index fi-
 521          * eld.  If the pager supports multiple orders, it may return an array of
 522          * 'querykey' => 'indexfield' pairs, so that a request with &count=querykey
 523          * will use indexfield to sort.  In this case, the first returned key is
 524          * the default.
 525          *
 526          * Needless to say, it's really not a good idea to use a non-unique index
 527          * for this!  That won't page right.
 528          */
 529         abstract function getIndexField();
 530
 531         /**
 532          * Return the default sorting direction: false for ascending, true for de-
 533          * scending.  You can also have an associative array of ordertype => dir,
 534          * if multiple order types are supported.  In this case getIndexField()
 535          * must return an array, and the keys of that must exactly match the keys
 536          * of this.
 537          *
 538          * For backward compatibility, this method's return value will be ignored
 539          * if $this->mDefaultDirection is already set when the constructor is
 540          * called, for instance if it's statically initialized.  In that case the
 541          * value of that variable (which must be a boolean) will be used.
 542          *
 543          * Note that despite its name, this does not return the value of the
 544          * $this->mDefaultDirection member variable.  That's the default for this
 545          * particular instantiation, which is a single value.  This is the set of
 546          * all defaults for the class.
 547          */
 548         protected function getDefaultDirections() { return false; }
 549 }
 550
 551
 552 /**
 553  * IndexPager with an alphabetic list and a formatted navigation bar
 554  * @ingroup Pager
 555  */
 556 abstract class AlphabeticPager extends IndexPager {
 557         /**
 558          * Shamelessly stolen bits from ReverseChronologicalPager,
 559          * didn't want to do class magic as may be still revamped
 560          */
 561         function getNavigationBar() {
 562                 global $wgLang;
 563
 564                 if ( !$this->isNavigationBarShown() ) return '';
 565
 566                 if( isset( $this->mNavigationBar ) ) {
 567                         return $this->mNavigationBar;
 568                 }
 569
 570                 $opts = array( 'parsemag', 'escapenoentities' );
 571                 $linkTexts = array(
 572                         'prev' => wfMsgExt(
 573                                 'prevn',
 574                                 $opts,
 575                                 $wgLang->formatNum( $this->mLimit )
 576                         ),
 577                         'next' => wfMsgExt(
 578                                 'nextn',
 579                                 $opts,
 580                                 $wgLang->formatNum($this->mLimit )
 581                         ),
 582                         'first' => wfMsgExt( 'page_first', $opts ),
 583                         'last' => wfMsgExt( 'page_last', $opts )
 584                 );
 585
 586                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 587                 $limitLinks = $this->getLimitLinks();
 588                 $limits = $wgLang->pipeList( $limitLinks );
 589
 590                 $this->mNavigationBar =
 591                         "(" . $wgLang->pipeList(
 592                                 array( $pagingLinks['first'],
 593                                 $pagingLinks['last'] )
 594                         ) . ") " .
 595                         wfMsgHtml( 'viewprevnext', $pagingLinks['prev'],
 596                         $pagingLinks['next'], $limits );
 597
 598                 if( !is_array( $this->getIndexField() ) ) {
 599                         # Early return to avoid undue nesting
 600                         return $this->mNavigationBar;
 601                 }
 602
 603                 $extra = '';
 604                 $first = true;
 605                 $msgs = $this->getOrderTypeMessages();
 606                 foreach( array_keys( $msgs ) as $order ) {
 607                         if( $first ) {
 608                                 $first = false;
 609                         } else {
 610                                 $extra .= wfMsgExt( 'pipe-separator' , 'escapenoentities' );
 611                         }
 612
 613                         if( $order == $this->mOrderType ) {
 614                                 $extra .= wfMsgHTML( $msgs[$order] );
 615                         } else {
 616                                 $extra .= $this->makeLink(
 617                                         wfMsgHTML( $msgs[$order] ),
 618                                         array( 'order' => $order )
 619                                 );
 620                         }
 621                 }
 622
 623                 if( $extra !== '' ) {
 624                         $this->mNavigationBar .= " ($extra)";
 625                 }
 626
 627                 return $this->mNavigationBar;
 628         }
 629
 630         /**
 631          * If this supports multiple order type messages, give the message key for
 632          * enabling each one in getNavigationBar.  The return type is an associa-
 633          * tive array whose keys must exactly match the keys of the array returned
 634          * by getIndexField(), and whose values are message keys.
 635          * @return array
 636          */
 637         protected function getOrderTypeMessages() {
 638                 return null;
 639         }
 640 }
 641
 642 /**
 643  * IndexPager with a formatted navigation bar
 644  * @ingroup Pager
 645  */
 646 abstract class ReverseChronologicalPager extends IndexPager {
 647         public $mDefaultDirection = true;
 648         public $mYear;
 649         public $mMonth;
 650
 651         function __construct() {
 652                 parent::__construct();
 653         }
 654
 655         function getNavigationBar() {
 656                 global $wgLang;
 657
 658                 if ( !$this->isNavigationBarShown() ) return '';
 659
 660                 if ( isset( $this->mNavigationBar ) ) {
 661                         return $this->mNavigationBar;
 662                 }
 663                 $nicenumber = $wgLang->formatNum( $this->mLimit );
 664                 $linkTexts = array(
 665                         'prev' => wfMsgExt(
 666                                 'pager-newer-n',
 667                                 array( 'parsemag', 'escape' ),
 668                                 $nicenumber
 669                         ),
 670                         'next' => wfMsgExt(
 671                                 'pager-older-n',
 672                                 array( 'parsemag', 'escape' ),
 673                                 $nicenumber
 674                         ),
 675                         'first' => wfMsgHtml( 'histlast' ),
 676                         'last' => wfMsgHtml( 'histfirst' )
 677                 );
 678
 679                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 680                 $limitLinks = $this->getLimitLinks();
 681                 $limits = $wgLang->pipeList( $limitLinks );
 682
 683                 $this->mNavigationBar = "({$pagingLinks['first']}" .
 684                         wfMsgExt( 'pipe-separator' , 'escapenoentities' ) .
 685                         "{$pagingLinks['last']}) " .
 686                         wfMsgHTML(
 687                                 'viewprevnext',
 688                                 $pagingLinks['prev'], $pagingLinks['next'],
 689                                 $limits
 690                         );
 691                 return $this->mNavigationBar;
 692         }
 693
 694         function getDateCond( $year, $month ) {
 695                 $year = intval($year);
 696                 $month = intval($month);
 697                 // Basic validity checks
 698                 $this->mYear = $year > 0 ? $year : false;
 699                 $this->mMonth = ($month > 0 && $month < 13) ? $month : false;
 700                 // Given an optional year and month, we need to generate a timestamp
 701                 // to use as "WHERE rev_timestamp <= result"
 702                 // Examples: year = 2006 equals < 20070101 (+000000)
 703                 // year=2005, month=1    equals < 20050201
 704                 // year=2005, month=12   equals < 20060101
 705                 if ( !$this->mYear && !$this->mMonth ) {
 706                         return;
 707                 }
 708                 if ( $this->mYear ) {
 709                         $year = $this->mYear;
 710                 } else {
 711                         // If no year given, assume the current one
 712                         $year = gmdate( 'Y' );
 713                         // If this month hasn't happened yet this year, go back to last year's month
 714                         if( $this->mMonth > gmdate( 'n' ) ) {
 715                                 $year--;
 716                         }
 717                 }
 718                 if ( $this->mMonth ) {
 719                         $month = $this->mMonth + 1;
 720                         // For December, we want January 1 of the next year
 721                         if ($month > 12) {
 722                                 $month = 1;
 723                                 $year++;
 724                         }
 725                 } else {
 726                         // No month implies we want up to the end of the year in question
 727                         $month = 1;
 728                         $year++;
 729                 }
 730                 // Y2K38 bug
 731                 if ( $year > 2032 ) {
 732                         $year = 2032;
 733                 }
 734                 $ymd = (int)sprintf( "%04d%02d01", $year, $month );
 735                 if ( $ymd > 20320101 ) {
 736                         $ymd = 20320101;
 737                 }
 738                 $this->mOffset = $this->mDb->timestamp( "${ymd}000000" );
 739         }
 740 }
 741
 742 /**
 743  * Table-based display with a user-selectable sort order
 744  * @ingroup Pager
 745  */
 746 abstract class TablePager extends IndexPager {
 747         var $mSort;
 748         var $mCurrentRow;
 749
 750         function __construct() {
 751                 global $wgRequest;
 752                 $this->mSort = $wgRequest->getText( 'sort' );
 753                 if ( !array_key_exists( $this->mSort, $this->getFieldNames() ) ) {
 754                         $this->mSort = $this->getDefaultSort();
 755                 }
 756                 if ( $wgRequest->getBool( 'asc' ) ) {
 757                         $this->mDefaultDirection = false;
 758                 } elseif ( $wgRequest->getBool( 'desc' ) ) {
 759                         $this->mDefaultDirection = true;
 760                 } /* Else leave it at whatever the class default is */
 761
 762                 parent::__construct();
 763         }
 764
 765         function getStartBody() {
 766                 global $wgStylePath;
 767                 $tableClass = htmlspecialchars( $this->getTableClass() );
 768                 $sortClass = htmlspecialchars( $this->getSortHeaderClass() );
 769
 770                 $s = "<table border='1' class=\"$tableClass\"><thead><tr>\n";
 771                 $fields = $this->getFieldNames();
 772
 773                 # Make table header
 774                 foreach ( $fields as $field => $name ) {
 775                         if ( strval( $name ) == '' ) {
 776                                 $s .= "<th>&nbsp;</th>\n";
 777                         } elseif ( $this->isFieldSortable( $field ) ) {
 778                                 $query = array( 'sort' => $field, 'limit' => $this->mLimit );
 779                                 if ( $field == $this->mSort ) {
 780                                         # This is the sorted column
 781                                         # Prepare a link that goes in the other sort order
 782                                         if ( $this->mDefaultDirection ) {
 783                                                 # Descending
 784                                                 $image = 'Arr_u.png';
 785                                                 $query['asc'] = '1';
 786                                                 $query['desc'] = '';
 787                                                 $alt = htmlspecialchars( wfMsg( 'descending_abbrev' ) );
 788                                         } else {
 789                                                 # Ascending
 790                                                 $image = 'Arr_d.png';
 791                                                 $query['asc'] = '';
 792                                                 $query['desc'] = '1';
 793                                                 $alt = htmlspecialchars( wfMsg( 'ascending_abbrev' ) );
 794                                         }
 795                                         $image = htmlspecialchars( "$wgStylePath/common/images/$image" );
 796                                         $link = $this->makeLink(
 797                                                 "<img width=\"12\" height=\"12\" alt=\"$alt\" src=\"$image\" />" .
 798                                                 htmlspecialchars( $name ), $query );
 799                                         $s .= "<th class=\"$sortClass\">$link</th>\n";
 800                                 } else {
 801                                         $s .= '<th>' . $this->makeLink( htmlspecialchars( $name ), $query ) . "</th>\n";
 802                                 }
 803                         } else {
 804                                 $s .= '<th>' . htmlspecialchars( $name ) . "</th>\n";
 805                         }
 806                 }
 807                 $s .= "</tr></thead><tbody>\n";
 808                 return $s;
 809         }
 810
 811         function getEndBody() {
 812                 return "</tbody></table>\n";
 813         }
 814
 815         function getEmptyBody() {
 816                 $colspan = count( $this->getFieldNames() );
 817                 $msgEmpty = wfMsgHtml( 'table_pager_empty' );
 818                 return "<tr><td colspan=\"$colspan\">$msgEmpty</td></tr>\n";
 819         }
 820
 821         function formatRow( $row ) {
 822                 $this->mCurrentRow = $row;      # In case formatValue etc need to know
 823                 $s = Xml::openElement( 'tr', $this->getRowAttrs($row) );
 824                 $fieldNames = $this->getFieldNames();
 825                 foreach ( $fieldNames as $field => $name ) {
 826                         $value = isset( $row->$field ) ? $row->$field : null;
 827                         $formatted = strval( $this->formatValue( $field, $value ) );
 828                         if ( $formatted == '' ) {
 829                                 $formatted = '&nbsp;';
 830                         }
 831                         $s .= Xml::tags( 'td', $this->getCellAttrs( $field, $value ), $formatted );
 832                 }
 833                 $s .= "</tr>\n";
 834                 return $s;
 835         }
 836
 837         /**
 838          * Get a class name to be applied to the given row.
 839          * @param object $row The database result row
 840          */
 841         function getRowClass( $row ) {
 842                 return '';
 843         }
 844
 845         /**
 846          * Get attributes to be applied to the given row.
 847          * @param object $row The database result row
 848          * @return associative array
 849          */
 850         function getRowAttrs( $row ) {
 851                 return array( 'class' => $this->getRowClass( $row ) );
 852         }
 853
 854         /**
 855          * Get any extra attributes to be applied to the given cell. Don't
 856          * take this as an excuse to hardcode styles; use classes and
 857          * CSS instead.  Row context is available in $this->mCurrentRow
 858          * @param $field The column
 859          * @param $value The cell contents
 860          * @return associative array
 861          */
 862         function getCellAttrs( $field, $value ) {
 863                 return array( 'class' => 'TablePager_col_' . $field );
 864         }
 865
 866         function getIndexField() {
 867                 return $this->mSort;
 868         }
 869
 870         function getTableClass() {
 871                 return 'TablePager';
 872         }
 873
 874         function getNavClass() {
 875                 return 'TablePager_nav';
 876         }
 877
 878         function getSortHeaderClass() {
 879                 return 'TablePager_sort';
 880         }
 881
 882         /**
 883          * A navigation bar with images
 884          */
 885         function getNavigationBar() {
 886                 global $wgStylePath, $wgContLang;
 887
 888                 if ( !$this->isNavigationBarShown() ) return '';
 889
 890                 $path = "$wgStylePath/common/images";
 891                 $labels = array(
 892                         'first' => 'table_pager_first',
 893                         'prev' => 'table_pager_prev',
 894                         'next' => 'table_pager_next',
 895                         'last' => 'table_pager_last',
 896                 );
 897                 $images = array(
 898                         'first' => 'arrow_first_25.png',
 899                         'prev' => 'arrow_left_25.png',
 900                         'next' => 'arrow_right_25.png',
 901                         'last' => 'arrow_last_25.png',
 902                 );
 903                 $disabledImages = array(
 904                         'first' => 'arrow_disabled_first_25.png',
 905                         'prev' => 'arrow_disabled_left_25.png',
 906                         'next' => 'arrow_disabled_right_25.png',
 907                         'last' => 'arrow_disabled_last_25.png',
 908                 );
 909                 if( $wgContLang->isRTL() ) {
 910                         $keys = array_keys( $labels );
 911                         $images = array_combine( $keys, array_reverse( $images ) );
 912                         $disabledImages = array_combine( $keys, array_reverse( $disabledImages ) );
 913                 }
 914
 915                 $linkTexts = array();
 916                 $disabledTexts = array();
 917                 foreach ( $labels as $type => $label ) {
 918                         $msgLabel = wfMsgHtml( $label );
 919                         $linkTexts[$type] = "<img src=\"$path/{$images[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
 920                         $disabledTexts[$type] = "<img src=\"$path/{$disabledImages[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
 921                 }
 922                 $links = $this->getPagingLinks( $linkTexts, $disabledTexts );
 923
 924                 $navClass = htmlspecialchars( $this->getNavClass() );
 925                 $s = "<table class=\"$navClass\" align=\"center\" cellpadding=\"3\"><tr>\n";
 926                 $cellAttrs = 'valign="top" align="center" width="' . 100 / count( $links ) . '%"';
 927                 foreach ( $labels as $type => $label ) {
 928                         $s .= "<td $cellAttrs>{$links[$type]}</td>\n";
 929                 }
 930                 $s .= "</tr></table>\n";
 931                 return $s;
 932         }
 933
 934         /**
 935          * Get a <select> element which has options for each of the allowed limits
 936          */
 937         function getLimitSelect() {
 938                 global $wgLang;
 939                 $s = "<select name=\"limit\">";
 940                 foreach ( $this->mLimitsShown as $key => $value ) {
 941                         # The pair is either $index => $limit, in which case the $value
 942                         # will be numeric, or $limit => $text, in which case the $value
 943                         # will be a string.
 944                         if( is_int( $value ) ){
 945                                 $limit = $value;
 946                                 $text = $wgLang->formatNum( $limit );
 947                         } else {
 948                                 $limit = $key;
 949                                 $text = $value;
 950                         }
 951                         $selected = ( $limit == $this->mLimit ? 'selected="selected"' : '' );
 952                         $s .= "<option value=\"$limit\" $selected>$text</option>\n";
 953                 }
 954                 $s .= "</select>";
 955                 return $s;
 956         }
 957
 958         /**
 959          * Get <input type="hidden"> elements for use in a method="get" form.
 960          * Resubmits all defined elements of the $_GET array, except for a
 961          * blacklist, passed in the $blacklist parameter.
 962          */
 963         function getHiddenFields( $blacklist = array() ) {
 964                 $blacklist = (array)$blacklist;
 965                 $query = $_GET;
 966                 foreach ( $blacklist as $name ) {
 967                         unset( $query[$name] );
 968                 }
 969                 $s = '';
 970                 foreach ( $query as $name => $value ) {
 971                         $encName = htmlspecialchars( $name );
 972                         $encValue = htmlspecialchars( $value );
 973                         $s .= "<input type=\"hidden\" name=\"$encName\" value=\"$encValue\"/>\n";
 974                 }
 975                 return $s;
 976         }
 977
 978         /**
 979          * Get a form containing a limit selection dropdown
 980          */
 981         function getLimitForm() {
 982                 global $wgScript;
 983
 984                 # Make the select with some explanatory text
 985                 $msgSubmit = wfMsgHtml( 'table_pager_limit_submit' );
 986                 return
 987                         Xml::openElement(
 988                                 'form',
 989                                 array(
 990                                         'method' => 'get',
 991                                         'action' => $wgScript
 992                                 )
 993                         ) . "\n" .
 994                         wfMsgHtml( 'table_pager_limit', $this->getLimitSelect() ) .
 995                         "\n<input type=\"submit\" value=\"$msgSubmit\"/>\n" .
 996                         $this->getHiddenFields( array( 'limit' ) ) .
 997                         "</form>\n";
 998         }
 999
1000         /**
1001          * Return true if the named field should be sortable by the UI, false
1002          * otherwise
1003          *
1004          * @param string $field
1005          */
1006         abstract function isFieldSortable( $field );
1007
1008         /**
1009          * Format a table cell. The return value should be HTML, but use an empty
1010          * string not &nbsp; for empty cells. Do not include the <td> and </td>.
1011          *
1012          * The current result row is available as $this->mCurrentRow, in case you
1013          * need more context.
1014          *
1015          * @param string $name The database field name
1016          * @param string $value The value retrieved from the database
1017          */
1018         abstract function formatValue( $name, $value );
1019
1020         /**
1021          * The database field name used as a default sort order
1022          */
1023         abstract function getDefaultSort();
1024
1025         /**
1026          * An array mapping database field names to a textual description of the
1027          * field name, for use in the table header. The description should be plain
1028          * text, it will be HTML-escaped later.
1029          */
1030         abstract function getFieldNames();
1031 }