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