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