includes/Pager.php

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