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 ResultWrapper 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          * @param $offset String: index offset, inclusive
 191          * @param $limit Integer: exact query limit
 192          * @param $res ResultWrapper
 193          */
 194         function extractResultInfo( $offset, $limit, ResultWrapper $res ) {
 195                 $numRows = $res->numRows();
 196                 if ( $numRows ) {
 197                         # Remove any table prefix from index field
 198                         $parts = explode( '.', $this->mIndexField );
 199                         $indexColumn = end( $parts );
 200
 201                         $row = $res->fetchRow();
 202                         $firstIndex = $row[$indexColumn];
 203
 204                         # Discard the extra result row if there is one
 205                         if ( $numRows > $this->mLimit && $numRows > 1 ) {
 206                                 $res->seek( $numRows - 1 );
 207                                 $this->mPastTheEndRow = $res->fetchObject();
 208                                 $indexField = $this->mIndexField;
 209                                 $this->mPastTheEndIndex = $this->mPastTheEndRow->$indexField;
 210                                 $res->seek( $numRows - 2 );
 211                                 $row = $res->fetchRow();
 212                                 $lastIndex = $row[$indexColumn];
 213                         } else {
 214                                 $this->mPastTheEndRow = null;
 215                                 # Setting indexes to an empty string means that they will be
 216                                 # omitted if they would otherwise appear in URLs. It just so
 217                                 # happens that this  is the right thing to do in the standard
 218                                 # UI, in all the relevant cases.
 219                                 $this->mPastTheEndIndex = '';
 220                                 $res->seek( $numRows - 1 );
 221                                 $row = $res->fetchRow();
 222                                 $lastIndex = $row[$indexColumn];
 223                         }
 224                 } else {
 225                         $firstIndex = '';
 226                         $lastIndex = '';
 227                         $this->mPastTheEndRow = null;
 228                         $this->mPastTheEndIndex = '';
 229                 }
 230
 231                 if ( $this->mIsBackwards ) {
 232                         $this->mIsFirst = ( $numRows < $limit );
 233                         $this->mIsLast = ( $offset == '' );
 234                         $this->mLastShown = $firstIndex;
 235                         $this->mFirstShown = $lastIndex;
 236                 } else {
 237                         $this->mIsFirst = ( $offset == '' );
 238                         $this->mIsLast = ( $numRows < $limit );
 239                         $this->mLastShown = $lastIndex;
 240                         $this->mFirstShown = $firstIndex;
 241                 }
 242         }
 243
 244         /**
 245          * Get some text to go in brackets in the "function name" part of the SQL comment
 246          *
 247          * @return String
 248          */
 249         function getSqlComment() {
 250                 return get_class( $this );
 251         }
 252
 253         /**
 254          * Do a query with specified parameters, rather than using the object
 255          * context
 256          *
 257          * @param $offset String: index offset, inclusive
 258          * @param $limit Integer: exact query limit
 259          * @param $descending Boolean: query direction, false for ascending, true for descending
 260          * @return ResultWrapper
 261          */
 262         function reallyDoQuery( $offset, $limit, $descending ) {
 263                 $fname = __METHOD__ . ' (' . $this->getSqlComment() . ')';
 264                 $info = $this->getQueryInfo();
 265                 $tables = $info['tables'];
 266                 $fields = $info['fields'];
 267                 $conds = isset( $info['conds'] ) ? $info['conds'] : array();
 268                 $options = isset( $info['options'] ) ? $info['options'] : array();
 269                 $join_conds = isset( $info['join_conds'] ) ? $info['join_conds'] : array();
 270                 if ( $descending ) {
 271                         $options['ORDER BY'] = $this->mIndexField;
 272                         $operator = '>';
 273                 } else {
 274                         $options['ORDER BY'] = $this->mIndexField . ' DESC';
 275                         $operator = '<';
 276                 }
 277                 if ( $offset != '' ) {
 278                         $conds[] = $this->mIndexField . $operator . $this->mDb->addQuotes( $offset );
 279                 }
 280                 $options['LIMIT'] = intval( $limit );
 281                 $res = $this->mDb->select( $tables, $fields, $conds, $fname, $options, $join_conds );
 282                 return new ResultWrapper( $this->mDb, $res );
 283         }
 284
 285         /**
 286          * Pre-process results; useful for performing batch existence checks, etc.
 287          *
 288          * @param $result ResultWrapper
 289          */
 290         protected function preprocessResults( $result ) {}
 291
 292         /**
 293          * Get the formatted result list. Calls getStartBody(), formatRow() and
 294          * getEndBody(), concatenates the results and returns them.
 295          *
 296          * @return String
 297          */
 298         function getBody() {
 299                 if ( !$this->mQueryDone ) {
 300                         $this->doQuery();
 301                 }
 302                 # Don't use any extra rows returned by the query
 303                 $numRows = min( $this->mResult->numRows(), $this->mLimit );
 304
 305                 $s = $this->getStartBody();
 306                 if ( $numRows ) {
 307                         if ( $this->mIsBackwards ) {
 308                                 for ( $i = $numRows - 1; $i >= 0; $i-- ) {
 309                                         $this->mResult->seek( $i );
 310                                         $row = $this->mResult->fetchObject();
 311                                         $s .= $this->formatRow( $row );
 312                                 }
 313                         } else {
 314                                 $this->mResult->seek( 0 );
 315                                 for ( $i = 0; $i < $numRows; $i++ ) {
 316                                         $row = $this->mResult->fetchObject();
 317                                         $s .= $this->formatRow( $row );
 318                                 }
 319                         }
 320                 } else {
 321                         $s .= $this->getEmptyBody();
 322                 }
 323                 $s .= $this->getEndBody();
 324                 return $s;
 325         }
 326
 327         /**
 328          * Make a self-link
 329          *
 330          * @param $text String: text displayed on the link
 331          * @param $query Array: associative array of paramter to be in the query string
 332          * @param $type String: value of the "rel" attribute
 333          * @return String: HTML fragment
 334          */
 335         function makeLink($text, $query = null, $type=null) {
 336                 if ( $query === null ) {
 337                         return $text;
 338                 }
 339
 340                 $attrs = array();
 341                 if( in_array( $type, array( 'first', 'prev', 'next', 'last' ) ) ) {
 342                         # HTML5 rel attributes
 343                         $attrs['rel'] = $type;
 344                 }
 345
 346                 if( $type ) {
 347                         $attrs['class'] = "mw-{$type}link";
 348                 }
 349                 return $this->getSkin()->link(
 350                         $this->getTitle(),
 351                         $text,
 352                         $attrs,
 353                         $query + $this->getDefaultQuery(),
 354                         array( 'noclasses', 'known' )
 355                 );
 356         }
 357
 358         /**
 359          * Hook into getBody(), allows text to be inserted at the start. This
 360          * will be called even if there are no rows in the result set.
 361          *
 362          * @return String
 363          */
 364         function getStartBody() {
 365                 return '';
 366         }
 367
 368         /**
 369          * Hook into getBody() for the end of the list
 370          *
 371          * @return String
 372          */
 373         function getEndBody() {
 374                 return '';
 375         }
 376
 377         /**
 378          * Hook into getBody(), for the bit between the start and the
 379          * end when there are no rows
 380          *
 381          * @return String
 382          */
 383         function getEmptyBody() {
 384                 return '';
 385         }
 386
 387         /**
 388          * Title used for self-links. Override this if you want to be able to
 389          * use a title other than $wgTitle
 390          *
 391          * @return Title object
 392          */
 393         function getTitle() {
 394                 return $GLOBALS['wgTitle'];
 395         }
 396
 397         /**
 398          * Get the current skin. This can be overridden if necessary.
 399          *
 400          * @return Skin object
 401          */
 402         function getSkin() {
 403                 if ( !isset( $this->mSkin ) ) {
 404                         global $wgUser;
 405                         $this->mSkin = $wgUser->getSkin();
 406                 }
 407                 return $this->mSkin;
 408         }
 409
 410         /**
 411          * Get an array of query parameters that should be put into self-links.
 412          * By default, all parameters passed in the URL are used, except for a
 413          * short blacklist.
 414          *
 415          * @return Associative array
 416          */
 417         function getDefaultQuery() {
 418                 if ( !isset( $this->mDefaultQuery ) ) {
 419                         $this->mDefaultQuery = $_GET;
 420                         unset( $this->mDefaultQuery['title'] );
 421                         unset( $this->mDefaultQuery['dir'] );
 422                         unset( $this->mDefaultQuery['offset'] );
 423                         unset( $this->mDefaultQuery['limit'] );
 424                         unset( $this->mDefaultQuery['order'] );
 425                         unset( $this->mDefaultQuery['month'] );
 426                         unset( $this->mDefaultQuery['year'] );
 427                 }
 428                 return $this->mDefaultQuery;
 429         }
 430
 431         /**
 432          * Get the number of rows in the result set
 433          *
 434          * @return Integer
 435          */
 436         function getNumRows() {
 437                 if ( !$this->mQueryDone ) {
 438                         $this->doQuery();
 439                 }
 440                 return $this->mResult->numRows();
 441         }
 442
 443         /**
 444          * Get a URL query array for the prev, next, first and last links.
 445          *
 446          * @return Array
 447          */
 448         function getPagingQueries() {
 449                 if ( !$this->mQueryDone ) {
 450                         $this->doQuery();
 451                 }
 452
 453                 # Don't announce the limit everywhere if it's the default
 454                 $urlLimit = $this->mLimit == $this->mDefaultLimit ? '' : $this->mLimit;
 455
 456                 if ( $this->mIsFirst ) {
 457                         $prev = false;
 458                         $first = false;
 459                 } else {
 460                         $prev = array(
 461                                 'dir' => 'prev',
 462                                 'offset' => $this->mFirstShown,
 463                                 'limit' => $urlLimit
 464                         );
 465                         $first = array( 'limit' => $urlLimit );
 466                 }
 467                 if ( $this->mIsLast ) {
 468                         $next = false;
 469                         $last = false;
 470                 } else {
 471                         $next = array( 'offset' => $this->mLastShown, 'limit' => $urlLimit );
 472                         $last = array( 'dir' => 'prev', 'limit' => $urlLimit );
 473                 }
 474                 return array(
 475                         'prev' => $prev,
 476                         'next' => $next,
 477                         'first' => $first,
 478                         'last' => $last
 479                 );
 480         }
 481
 482         /**
 483          * Returns whether to show the "navigation bar"
 484          *
 485          * @return Boolean
 486          */
 487         function isNavigationBarShown() {
 488                 if ( !$this->mQueryDone ) {
 489                         $this->doQuery();
 490                 }
 491                 // Hide navigation by default if there is nothing to page
 492                 return !($this->mIsFirst && $this->mIsLast);
 493         }
 494
 495         /**
 496          * Get paging links. If a link is disabled, the item from $disabledTexts
 497          * will be used. If there is no such item, the unlinked text from
 498          * $linkTexts will be used. Both $linkTexts and $disabledTexts are arrays
 499          * of HTML.
 500          *
 501          * @return Array
 502          */
 503         function getPagingLinks( $linkTexts, $disabledTexts = array() ) {
 504                 $queries = $this->getPagingQueries();
 505                 $links = array();
 506                 foreach ( $queries as $type => $query ) {
 507                         if ( $query !== false ) {
 508                                 $links[$type] = $this->makeLink(
 509                                         $linkTexts[$type],
 510                                         $queries[$type],
 511                                         $type
 512                                 );
 513                         } elseif ( isset( $disabledTexts[$type] ) ) {
 514                                 $links[$type] = $disabledTexts[$type];
 515                         } else {
 516                                 $links[$type] = $linkTexts[$type];
 517                         }
 518                 }
 519                 return $links;
 520         }
 521
 522         function getLimitLinks() {
 523                 global $wgLang;
 524                 $links = array();
 525                 if ( $this->mIsBackwards ) {
 526                         $offset = $this->mPastTheEndIndex;
 527                 } else {
 528                         $offset = $this->mOffset;
 529                 }
 530                 foreach ( $this->mLimitsShown as $limit ) {
 531                         $links[] = $this->makeLink(
 532                                 $wgLang->formatNum( $limit ),
 533                                 array( 'offset' => $offset, 'limit' => $limit ),
 534                                 'num'
 535                         );
 536                 }
 537                 return $links;
 538         }
 539
 540         /**
 541          * Abstract formatting function. This should return an HTML string
 542          * representing the result row $row. Rows will be concatenated and
 543          * returned by getBody()
 544          *
 545          * @param $row Object: database row
 546          * @return String
 547          */
 548         abstract function formatRow( $row );
 549
 550         /**
 551          * This function should be overridden to provide all parameters
 552          * needed for the main paged query. It returns an associative
 553          * array with the following elements:
 554          *    tables => Table(s) for passing to Database::select()
 555          *    fields => Field(s) for passing to Database::select(), may be *
 556          *    conds => WHERE conditions
 557          *    options => option array
 558          *    join_conds => JOIN conditions
 559          *
 560          * @return Array
 561          */
 562         abstract function getQueryInfo();
 563
 564         /**
 565          * This function should be overridden to return the name of the index fi-
 566          * eld.  If the pager supports multiple orders, it may return an array of
 567          * 'querykey' => 'indexfield' pairs, so that a request with &count=querykey
 568          * will use indexfield to sort.  In this case, the first returned key is
 569          * the default.
 570          *
 571          * Needless to say, it's really not a good idea to use a non-unique index
 572          * for this!  That won't page right.
 573          */
 574         abstract function getIndexField();
 575
 576         /**
 577          * Return the default sorting direction: false for ascending, true for de-
 578          * scending.  You can also have an associative array of ordertype => dir,
 579          * if multiple order types are supported.  In this case getIndexField()
 580          * must return an array, and the keys of that must exactly match the keys
 581          * of this.
 582          *
 583          * For backward compatibility, this method's return value will be ignored
 584          * if $this->mDefaultDirection is already set when the constructor is
 585          * called, for instance if it's statically initialized.  In that case the
 586          * value of that variable (which must be a boolean) will be used.
 587          *
 588          * Note that despite its name, this does not return the value of the
 589          * $this->mDefaultDirection member variable.  That's the default for this
 590          * particular instantiation, which is a single value.  This is the set of
 591          * all defaults for the class.
 592          *
 593          * @return Boolean
 594          */
 595         protected function getDefaultDirections() { return false; }
 596 }
 597
 598
 599 /**
 600  * IndexPager with an alphabetic list and a formatted navigation bar
 601  * @ingroup Pager
 602  */
 603 abstract class AlphabeticPager extends IndexPager {
 604         /**
 605          * Shamelessly stolen bits from ReverseChronologicalPager,
 606          * didn't want to do class magic as may be still revamped
 607          */
 608         function getNavigationBar() {
 609                 global $wgLang;
 610
 611                 if ( !$this->isNavigationBarShown() ) return '';
 612
 613                 if( isset( $this->mNavigationBar ) ) {
 614                         return $this->mNavigationBar;
 615                 }
 616
 617                 $opts = array( 'parsemag', 'escapenoentities' );
 618                 $linkTexts = array(
 619                         'prev' => wfMsgExt(
 620                                 'prevn',
 621                                 $opts,
 622                                 $wgLang->formatNum( $this->mLimit )
 623                         ),
 624                         'next' => wfMsgExt(
 625                                 'nextn',
 626                                 $opts,
 627                                 $wgLang->formatNum($this->mLimit )
 628                         ),
 629                         'first' => wfMsgExt( 'page_first', $opts ),
 630                         'last' => wfMsgExt( 'page_last', $opts )
 631                 );
 632
 633                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 634                 $limitLinks = $this->getLimitLinks();
 635                 $limits = $wgLang->pipeList( $limitLinks );
 636
 637                 $this->mNavigationBar =
 638                         "(" . $wgLang->pipeList(
 639                                 array( $pagingLinks['first'],
 640                                 $pagingLinks['last'] )
 641                         ) . ") " .
 642                         wfMsgHtml( 'viewprevnext', $pagingLinks['prev'],
 643                         $pagingLinks['next'], $limits );
 644
 645                 if( !is_array( $this->getIndexField() ) ) {
 646                         # Early return to avoid undue nesting
 647                         return $this->mNavigationBar;
 648                 }
 649
 650                 $extra = '';
 651                 $first = true;
 652                 $msgs = $this->getOrderTypeMessages();
 653                 foreach( array_keys( $msgs ) as $order ) {
 654                         if( $first ) {
 655                                 $first = false;
 656                         } else {
 657                                 $extra .= wfMsgExt( 'pipe-separator' , 'escapenoentities' );
 658                         }
 659
 660                         if( $order == $this->mOrderType ) {
 661                                 $extra .= wfMsgHTML( $msgs[$order] );
 662                         } else {
 663                                 $extra .= $this->makeLink(
 664                                         wfMsgHTML( $msgs[$order] ),
 665                                         array( 'order' => $order )
 666                                 );
 667                         }
 668                 }
 669
 670                 if( $extra !== '' ) {
 671                         $this->mNavigationBar .= " ($extra)";
 672                 }
 673
 674                 return $this->mNavigationBar;
 675         }
 676
 677         /**
 678          * If this supports multiple order type messages, give the message key for
 679          * enabling each one in getNavigationBar.  The return type is an associa-
 680          * tive array whose keys must exactly match the keys of the array returned
 681          * by getIndexField(), and whose values are message keys.
 682          *
 683          * @return Array
 684          */
 685         protected function getOrderTypeMessages() {
 686                 return null;
 687         }
 688 }
 689
 690 /**
 691  * IndexPager with a formatted navigation bar
 692  * @ingroup Pager
 693  */
 694 abstract class ReverseChronologicalPager extends IndexPager {
 695         public $mDefaultDirection = true;
 696         public $mYear;
 697         public $mMonth;
 698
 699         function __construct() {
 700                 parent::__construct();
 701         }
 702
 703         function getNavigationBar() {
 704                 global $wgLang;
 705
 706                 if ( !$this->isNavigationBarShown() ) return '';
 707
 708                 if ( isset( $this->mNavigationBar ) ) {
 709                         return $this->mNavigationBar;
 710                 }
 711                 $nicenumber = $wgLang->formatNum( $this->mLimit );
 712                 $linkTexts = array(
 713                         'prev' => wfMsgExt(
 714                                 'pager-newer-n',
 715                                 array( 'parsemag', 'escape' ),
 716                                 $nicenumber
 717                         ),
 718                         'next' => wfMsgExt(
 719                                 'pager-older-n',
 720                                 array( 'parsemag', 'escape' ),
 721                                 $nicenumber
 722                         ),
 723                         'first' => wfMsgHtml( 'histlast' ),
 724                         'last' => wfMsgHtml( 'histfirst' )
 725                 );
 726
 727                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 728                 $limitLinks = $this->getLimitLinks();
 729                 $limits = $wgLang->pipeList( $limitLinks );
 730
 731                 $this->mNavigationBar = "({$pagingLinks['first']}" .
 732                         wfMsgExt( 'pipe-separator' , 'escapenoentities' ) .
 733                         "{$pagingLinks['last']}) " .
 734                         wfMsgHTML(
 735                                 'viewprevnext',
 736                                 $pagingLinks['prev'], $pagingLinks['next'],
 737                                 $limits
 738                         );
 739                 return $this->mNavigationBar;
 740         }
 741
 742         function getDateCond( $year, $month ) {
 743                 $year = intval($year);
 744                 $month = intval($month);
 745                 // Basic validity checks
 746                 $this->mYear = $year > 0 ? $year : false;
 747                 $this->mMonth = ($month > 0 && $month < 13) ? $month : false;
 748                 // Given an optional year and month, we need to generate a timestamp
 749                 // to use as "WHERE rev_timestamp <= result"
 750                 // Examples: year = 2006 equals < 20070101 (+000000)
 751                 // year=2005, month=1    equals < 20050201
 752                 // year=2005, month=12   equals < 20060101
 753                 if ( !$this->mYear && !$this->mMonth ) {
 754                         return;
 755                 }
 756                 if ( $this->mYear ) {
 757                         $year = $this->mYear;
 758                 } else {
 759                         // If no year given, assume the current one
 760                         $year = gmdate( 'Y' );
 761                         // If this month hasn't happened yet this year, go back to last year's month
 762                         if( $this->mMonth > gmdate( 'n' ) ) {
 763                                 $year--;
 764                         }
 765                 }
 766                 if ( $this->mMonth ) {
 767                         $month = $this->mMonth + 1;
 768                         // For December, we want January 1 of the next year
 769                         if ($month > 12) {
 770                                 $month = 1;
 771                                 $year++;
 772                         }
 773                 } else {
 774                         // No month implies we want up to the end of the year in question
 775                         $month = 1;
 776                         $year++;
 777                 }
 778                 // Y2K38 bug
 779                 if ( $year > 2032 ) {
 780                         $year = 2032;
 781                 }
 782                 $ymd = (int)sprintf( "%04d%02d01", $year, $month );
 783                 if ( $ymd > 20320101 ) {
 784                         $ymd = 20320101;
 785                 }
 786                 $this->mOffset = $this->mDb->timestamp( "${ymd}000000" );
 787         }
 788 }
 789
 790 /**
 791  * Table-based display with a user-selectable sort order
 792  * @ingroup Pager
 793  */
 794 abstract class TablePager extends IndexPager {
 795         var $mSort;
 796         var $mCurrentRow;
 797
 798         function __construct() {
 799                 global $wgRequest;
 800                 $this->mSort = $wgRequest->getText( 'sort' );
 801                 if ( !array_key_exists( $this->mSort, $this->getFieldNames() ) ) {
 802                         $this->mSort = $this->getDefaultSort();
 803                 }
 804                 if ( $wgRequest->getBool( 'asc' ) ) {
 805                         $this->mDefaultDirection = false;
 806                 } elseif ( $wgRequest->getBool( 'desc' ) ) {
 807                         $this->mDefaultDirection = true;
 808                 } /* Else leave it at whatever the class default is */
 809
 810                 parent::__construct();
 811         }
 812
 813         function getStartBody() {
 814                 global $wgStylePath;
 815                 $tableClass = htmlspecialchars( $this->getTableClass() );
 816                 $sortClass = htmlspecialchars( $this->getSortHeaderClass() );
 817
 818                 $s = "<table border='1' class=\"$tableClass\"><thead><tr>\n";
 819                 $fields = $this->getFieldNames();
 820
 821                 # Make table header
 822                 foreach ( $fields as $field => $name ) {
 823                         if ( strval( $name ) == '' ) {
 824                                 $s .= "<th>&#160;</th>\n";
 825                         } elseif ( $this->isFieldSortable( $field ) ) {
 826                                 $query = array( 'sort' => $field, 'limit' => $this->mLimit );
 827                                 if ( $field == $this->mSort ) {
 828                                         # This is the sorted column
 829                                         # Prepare a link that goes in the other sort order
 830                                         if ( $this->mDefaultDirection ) {
 831                                                 # Descending
 832                                                 $image = 'Arr_u.png';
 833                                                 $query['asc'] = '1';
 834                                                 $query['desc'] = '';
 835                                                 $alt = htmlspecialchars( wfMsg( 'descending_abbrev' ) );
 836                                         } else {
 837                                                 # Ascending
 838                                                 $image = 'Arr_d.png';
 839                                                 $query['asc'] = '';
 840                                                 $query['desc'] = '1';
 841                                                 $alt = htmlspecialchars( wfMsg( 'ascending_abbrev' ) );
 842                                         }
 843                                         $image = htmlspecialchars( "$wgStylePath/common/images/$image" );
 844                                         $link = $this->makeLink(
 845                                                 "<img width=\"12\" height=\"12\" alt=\"$alt\" src=\"$image\" />" .
 846                                                 htmlspecialchars( $name ), $query );
 847                                         $s .= "<th class=\"$sortClass\">$link</th>\n";
 848                                 } else {
 849                                         $s .= '<th>' . $this->makeLink( htmlspecialchars( $name ), $query ) . "</th>\n";
 850                                 }
 851                         } else {
 852                                 $s .= '<th>' . htmlspecialchars( $name ) . "</th>\n";
 853                         }
 854                 }
 855                 $s .= "</tr></thead><tbody>\n";
 856                 return $s;
 857         }
 858
 859         function getEndBody() {
 860                 return "</tbody></table>\n";
 861         }
 862
 863         function getEmptyBody() {
 864                 $colspan = count( $this->getFieldNames() );
 865                 $msgEmpty = wfMsgHtml( 'table_pager_empty' );
 866                 return "<tr><td colspan=\"$colspan\">$msgEmpty</td></tr>\n";
 867         }
 868
 869         function formatRow( $row ) {
 870                 $this->mCurrentRow = $row;      # In case formatValue etc need to know
 871                 $s = Xml::openElement( 'tr', $this->getRowAttrs($row) );
 872                 $fieldNames = $this->getFieldNames();
 873                 foreach ( $fieldNames as $field => $name ) {
 874                         $value = isset( $row->$field ) ? $row->$field : null;
 875                         $formatted = strval( $this->formatValue( $field, $value ) );
 876                         if ( $formatted == '' ) {
 877                                 $formatted = '&#160;';
 878                         }
 879                         $s .= Xml::tags( 'td', $this->getCellAttrs( $field, $value ), $formatted );
 880                 }
 881                 $s .= "</tr>\n";
 882                 return $s;
 883         }
 884
 885         /**
 886          * Get a class name to be applied to the given row.
 887          *
 888          * @param $row Object: the database result row
 889          * @return String
 890          */
 891         function getRowClass( $row ) {
 892                 return '';
 893         }
 894
 895         /**
 896          * Get attributes to be applied to the given row.
 897          *
 898          * @param $row Object: the database result row
 899          * @return Associative array
 900          */
 901         function getRowAttrs( $row ) {
 902                 return array( 'class' => $this->getRowClass( $row ) );
 903         }
 904
 905         /**
 906          * Get any extra attributes to be applied to the given cell. Don't
 907          * take this as an excuse to hardcode styles; use classes and
 908          * CSS instead.  Row context is available in $this->mCurrentRow
 909          *
 910          * @param $field The column
 911          * @param $value The cell contents
 912          * @return Associative array
 913          */
 914         function getCellAttrs( $field, $value ) {
 915                 return array( 'class' => 'TablePager_col_' . $field );
 916         }
 917
 918         function getIndexField() {
 919                 return $this->mSort;
 920         }
 921
 922         function getTableClass() {
 923                 return 'TablePager';
 924         }
 925
 926         function getNavClass() {
 927                 return 'TablePager_nav';
 928         }
 929
 930         function getSortHeaderClass() {
 931                 return 'TablePager_sort';
 932         }
 933
 934         /**
 935          * A navigation bar with images
 936          */
 937         function getNavigationBar() {
 938                 global $wgStylePath, $wgContLang;
 939
 940                 if ( !$this->isNavigationBarShown() ) {
 941                         return '';
 942                 }
 943
 944                 $path = "$wgStylePath/common/images";
 945                 $labels = array(
 946                         'first' => 'table_pager_first',
 947                         'prev' => 'table_pager_prev',
 948                         'next' => 'table_pager_next',
 949                         'last' => 'table_pager_last',
 950                 );
 951                 $images = array(
 952                         'first' => 'arrow_first_25.png',
 953                         'prev' => 'arrow_left_25.png',
 954                         'next' => 'arrow_right_25.png',
 955                         'last' => 'arrow_last_25.png',
 956                 );
 957                 $disabledImages = array(
 958                         'first' => 'arrow_disabled_first_25.png',
 959                         'prev' => 'arrow_disabled_left_25.png',
 960                         'next' => 'arrow_disabled_right_25.png',
 961                         'last' => 'arrow_disabled_last_25.png',
 962                 );
 963                 if( $wgContLang->isRTL() ) {
 964                         $keys = array_keys( $labels );
 965                         $images = array_combine( $keys, array_reverse( $images ) );
 966                         $disabledImages = array_combine( $keys, array_reverse( $disabledImages ) );
 967                 }
 968
 969                 $linkTexts = array();
 970                 $disabledTexts = array();
 971                 foreach ( $labels as $type => $label ) {
 972                         $msgLabel = wfMsgHtml( $label );
 973                         $linkTexts[$type] = "<img src=\"$path/{$images[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
 974                         $disabledTexts[$type] = "<img src=\"$path/{$disabledImages[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
 975                 }
 976                 $links = $this->getPagingLinks( $linkTexts, $disabledTexts );
 977
 978                 $navClass = htmlspecialchars( $this->getNavClass() );
 979                 $s = "<table class=\"$navClass\" align=\"center\" cellpadding=\"3\"><tr>\n";
 980                 $cellAttrs = 'valign="top" align="center" width="' . 100 / count( $links ) . '%"';
 981                 foreach ( $labels as $type => $label ) {
 982                         $s .= "<td $cellAttrs>{$links[$type]}</td>\n";
 983                 }
 984                 $s .= "</tr></table>\n";
 985                 return $s;
 986         }
 987
 988         /**
 989          * Get a <select> element which has options for each of the allowed limits
 990          *
 991          * @return String: HTML fragment
 992          */
 993         function getLimitSelect() {
 994                 global $wgLang;
 995
 996                 # Add the current limit from the query string
 997                 # to avoid that the limit is lost after clicking Go next time
 998                 if ( !in_array( $this->mLimit, $this->mLimitsShown ) ) {
 999                         $this->mLimitsShown[] = $this->mLimit;
1000                         sort( $this->mLimitsShown );
1001                 }
1002                 $s = Html::openElement( 'select', array( 'name' => 'limit' ) ) . "\n";
1003                 foreach ( $this->mLimitsShown as $key => $value ) {
1004                         # The pair is either $index => $limit, in which case the $value
1005                         # will be numeric, or $limit => $text, in which case the $value
1006                         # will be a string.
1007                         if( is_int( $value ) ){
1008                                 $limit = $value;
1009                                 $text = $wgLang->formatNum( $limit );
1010                         } else {
1011                                 $limit = $key;
1012                                 $text = $value;
1013                         }
1014                         $s .= Xml::option( $text, $limit, $limit == $this->mLimit ) . "\n";
1015                 }
1016                 $s .= Html::closeElement( 'select' );
1017                 return $s;
1018         }
1019
1020         /**
1021          * Get <input type="hidden"> elements for use in a method="get" form.
1022          * Resubmits all defined elements of the $_GET array, except for a
1023          * blacklist, passed in the $blacklist parameter.
1024          *
1025          * @return String: HTML fragment
1026          */
1027         function getHiddenFields( $blacklist = array() ) {
1028                 $blacklist = (array)$blacklist;
1029                 $query = $_GET;
1030                 foreach ( $blacklist as $name ) {
1031                         unset( $query[$name] );
1032                 }
1033                 $s = '';
1034                 foreach ( $query as $name => $value ) {
1035                         $encName = htmlspecialchars( $name );
1036                         $encValue = htmlspecialchars( $value );
1037                         $s .= "<input type=\"hidden\" name=\"$encName\" value=\"$encValue\"/>\n";
1038                 }
1039                 return $s;
1040         }
1041
1042         /**
1043          * Get a form containing a limit selection dropdown
1044          *
1045          * @return String: HTML fragment
1046          */
1047         function getLimitForm() {
1048                 global $wgScript;
1049
1050                 return Xml::openElement(
1051                         'form',
1052                         array(
1053                                 'method' => 'get',
1054                                 'action' => $wgScript
1055                         ) ) . "\n" . $this->getLimitDropdown() . "</form>\n";
1056         }
1057
1058         /**
1059          * Gets a limit selection dropdown
1060          *
1061          * @return string
1062          */
1063         function getLimitDropdown() {
1064                 # Make the select with some explanatory text
1065                 $msgSubmit = wfMsgHtml( 'table_pager_limit_submit' );
1066
1067                 return wfMsgHtml( 'table_pager_limit', $this->getLimitSelect() ) .
1068                         "\n<input type=\"submit\" value=\"$msgSubmit\"/>\n" .
1069                         $this->getHiddenFields( array( 'limit' ) );
1070         }
1071
1072         /**
1073          * Return true if the named field should be sortable by the UI, false
1074          * otherwise
1075          *
1076          * @param $field String
1077          */
1078         abstract function isFieldSortable( $field );
1079
1080         /**
1081          * Format a table cell. The return value should be HTML, but use an empty
1082          * string not &#160; for empty cells. Do not include the <td> and </td>.
1083          *
1084          * The current result row is available as $this->mCurrentRow, in case you
1085          * need more context.
1086          *
1087          * @param $name String: the database field name
1088          * @param $value String: the value retrieved from the database
1089          */
1090         abstract function formatValue( $name, $value );
1091
1092         /**
1093          * The database field name used as a default sort order
1094          */
1095         abstract function getDefaultSort();
1096
1097         /**
1098          * An array mapping database field names to a textual description of the
1099          * field name, for use in the table header. The description should be plain
1100          * text, it will be HTML-escaped later.
1101          */
1102         abstract function getFieldNames();
1103 }