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