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  *  SpecialBlockList.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 extends ContextSource 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 column,
  71          * for one ordering, even if multiple orderings are supported.
  72          */
  73         protected $mIndexField;
  74         /**
  75          * An array of secondary columns to order by. These fields are not part of the offset.
  76          * This is a column list for one ordering, even if multiple orderings are supported.
  77          */
  78         protected $mExtraSortFields;
  79         /** For pages that support multiple types of ordering, which one to use.
  80          */
  81         protected $mOrderType;
  82         /**
  83          * $mDefaultDirection gives the direction to use when sorting results:
  84          * false for ascending, true for descending.  If $mIsBackwards is set, we
  85          * start from the opposite end, but we still sort the page itself according
  86          * to $mDefaultDirection.  E.g., if $mDefaultDirection is false but we're
  87          * going backwards, we'll display the last page of results, but the last
  88          * result will be at the bottom, not the top.
  89          *
  90          * Like $mIndexField, $mDefaultDirection will be a single value even if the
  91          * class supports multiple default directions for different order types.
  92          */
  93         public $mDefaultDirection;
  94         public $mIsBackwards;
  95
  96         /** True if the current result set is the first one */
  97         public $mIsFirst;
  98
  99         /**
 100          * Result object for the query. Warning: seek before use.
 101          *
 102          * @var ResultWrapper
 103          */
 104         public $mResult;
 105
 106         public function __construct( RequestContext $context = null ) {
 107                 if ( $context ) {
 108                         $this->setContext( $context );
 109                 }
 110
 111                 $this->mRequest = $this->getRequest();
 112
 113                 # NB: the offset is quoted, not validated. It is treated as an
 114                 # arbitrary string to support the widest variety of index types. Be
 115                 # careful outputting it into HTML!
 116                 $this->mOffset = $this->mRequest->getText( 'offset' );
 117
 118                 # Use consistent behavior for the limit options
 119                 $this->mDefaultLimit = intval( $this->getUser()->getOption( 'rclimit' ) );
 120                 list( $this->mLimit, /* $offset */ ) = $this->mRequest->getLimitOffset();
 121
 122                 $this->mIsBackwards = ( $this->mRequest->getVal( 'dir' ) == 'prev' );
 123                 $this->mDb = wfGetDB( DB_SLAVE );
 124
 125                 $index = $this->getIndexField(); // column to sort on
 126                 $extraSort = $this->getExtraSortFields(); // extra columns to sort on for query planning
 127                 $order = $this->mRequest->getVal( 'order' );
 128                 if( is_array( $index ) && isset( $index[$order] ) ) {
 129                         $this->mOrderType = $order;
 130                         $this->mIndexField = $index[$order];
 131                         $this->mExtraSortFields = isset( $extraSort[$order] )
 132                                 ? (array)$extraSort[$order]
 133                                 : array();
 134                 } elseif( is_array( $index ) ) {
 135                         # First element is the default
 136                         reset( $index );
 137                         list( $this->mOrderType, $this->mIndexField ) = each( $index );
 138                         $this->mExtraSortFields = isset( $extraSort[$this->mOrderType] )
 139                                 ? (array)$extraSort[$this->mOrderType]
 140                                 : array();
 141                 } else {
 142                         # $index is not an array
 143                         $this->mOrderType = null;
 144                         $this->mIndexField = $index;
 145                         $this->mExtraSortFields = (array)$extraSort;
 146                 }
 147
 148                 if( !isset( $this->mDefaultDirection ) ) {
 149                         $dir = $this->getDefaultDirections();
 150                         $this->mDefaultDirection = is_array( $dir )
 151                                 ? $dir[$this->mOrderType]
 152                                 : $dir;
 153                 }
 154         }
 155
 156         /**
 157          * Do the query, using information from the object context. This function
 158          * has been kept minimal to make it overridable if necessary, to allow for
 159          * result sets formed from multiple DB queries.
 160          */
 161         public function doQuery() {
 162                 # Use the child class name for profiling
 163                 $fname = __METHOD__ . ' (' . get_class( $this ) . ')';
 164                 wfProfileIn( $fname );
 165
 166                 $descending = ( $this->mIsBackwards == $this->mDefaultDirection );
 167                 # Plus an extra row so that we can tell the "next" link should be shown
 168                 $queryLimit = $this->mLimit + 1;
 169
 170                 $this->mResult = $this->reallyDoQuery(
 171                         $this->mOffset,
 172                         $queryLimit,
 173                         $descending
 174                 );
 175                 $this->extractResultInfo( $this->mOffset, $queryLimit, $this->mResult );
 176                 $this->mQueryDone = true;
 177
 178                 $this->preprocessResults( $this->mResult );
 179                 $this->mResult->rewind(); // Paranoia
 180
 181                 wfProfileOut( $fname );
 182         }
 183
 184         /**
 185          * @return ResultWrapper The result wrapper.
 186          */
 187         function getResult() {
 188                 return $this->mResult;
 189         }
 190
 191         /**
 192          * Set the offset from an other source than the request
 193          */
 194         function setOffset( $offset ) {
 195                 $this->mOffset = $offset;
 196         }
 197         /**
 198          * Set the limit from an other source than the request
 199          */
 200         function setLimit( $limit ) {
 201                 $this->mLimit = $limit;
 202         }
 203
 204         /**
 205          * Extract some useful data from the result object for use by
 206          * the navigation bar, put it into $this
 207          *
 208          * @param $offset String: index offset, inclusive
 209          * @param $limit Integer: exact query limit
 210          * @param $res ResultWrapper
 211          */
 212         function extractResultInfo( $offset, $limit, ResultWrapper $res ) {
 213                 $numRows = $res->numRows();
 214                 if ( $numRows ) {
 215                         # Remove any table prefix from index field
 216                         $parts = explode( '.', $this->mIndexField );
 217                         $indexColumn = end( $parts );
 218
 219                         $row = $res->fetchRow();
 220                         $firstIndex = $row[$indexColumn];
 221
 222                         # Discard the extra result row if there is one
 223                         if ( $numRows > $this->mLimit && $numRows > 1 ) {
 224                                 $res->seek( $numRows - 1 );
 225                                 $this->mPastTheEndRow = $res->fetchObject();
 226                                 $indexField = $this->mIndexField;
 227                                 $this->mPastTheEndIndex = $this->mPastTheEndRow->$indexField;
 228                                 $res->seek( $numRows - 2 );
 229                                 $row = $res->fetchRow();
 230                                 $lastIndex = $row[$indexColumn];
 231                         } else {
 232                                 $this->mPastTheEndRow = null;
 233                                 # Setting indexes to an empty string means that they will be
 234                                 # omitted if they would otherwise appear in URLs. It just so
 235                                 # happens that this  is the right thing to do in the standard
 236                                 # UI, in all the relevant cases.
 237                                 $this->mPastTheEndIndex = '';
 238                                 $res->seek( $numRows - 1 );
 239                                 $row = $res->fetchRow();
 240                                 $lastIndex = $row[$indexColumn];
 241                         }
 242                 } else {
 243                         $firstIndex = '';
 244                         $lastIndex = '';
 245                         $this->mPastTheEndRow = null;
 246                         $this->mPastTheEndIndex = '';
 247                 }
 248
 249                 if ( $this->mIsBackwards ) {
 250                         $this->mIsFirst = ( $numRows < $limit );
 251                         $this->mIsLast = ( $offset == '' );
 252                         $this->mLastShown = $firstIndex;
 253                         $this->mFirstShown = $lastIndex;
 254                 } else {
 255                         $this->mIsFirst = ( $offset == '' );
 256                         $this->mIsLast = ( $numRows < $limit );
 257                         $this->mLastShown = $lastIndex;
 258                         $this->mFirstShown = $firstIndex;
 259                 }
 260         }
 261
 262         /**
 263          * Get some text to go in brackets in the "function name" part of the SQL comment
 264          *
 265          * @return String
 266          */
 267         function getSqlComment() {
 268                 return get_class( $this );
 269         }
 270
 271         /**
 272          * Do a query with specified parameters, rather than using the object
 273          * context
 274          *
 275          * @param $offset String: index offset, inclusive
 276          * @param $limit Integer: exact query limit
 277          * @param $descending Boolean: query direction, false for ascending, true for descending
 278          * @return ResultWrapper
 279          */
 280         function reallyDoQuery( $offset, $limit, $descending ) {
 281                 $fname = __METHOD__ . ' (' . $this->getSqlComment() . ')';
 282                 $info = $this->getQueryInfo();
 283                 $tables = $info['tables'];
 284                 $fields = $info['fields'];
 285                 $conds = isset( $info['conds'] ) ? $info['conds'] : array();
 286                 $options = isset( $info['options'] ) ? $info['options'] : array();
 287                 $join_conds = isset( $info['join_conds'] ) ? $info['join_conds'] : array();
 288                 $sortColumns = array_merge( array( $this->mIndexField ), $this->mExtraSortFields );
 289                 if ( $descending ) {
 290                         $options['ORDER BY'] = implode( ',', $sortColumns );
 291                         $operator = '>';
 292                 } else {
 293                         $orderBy = array();
 294                         foreach ( $sortColumns as $col ) {
 295                                 $orderBy[] = $col . ' DESC';
 296                         }
 297                         $options['ORDER BY'] = implode( ',', $orderBy );
 298                         $operator = '<';
 299                 }
 300                 if ( $offset != '' ) {
 301                         $conds[] = $this->mIndexField . $operator . $this->mDb->addQuotes( $offset );
 302                 }
 303                 $options['LIMIT'] = intval( $limit );
 304                 $res = $this->mDb->select( $tables, $fields, $conds, $fname, $options, $join_conds );
 305                 return new ResultWrapper( $this->mDb, $res );
 306         }
 307
 308         /**
 309          * Pre-process results; useful for performing batch existence checks, etc.
 310          *
 311          * @param $result ResultWrapper
 312          */
 313         protected function preprocessResults( $result ) {}
 314
 315         /**
 316          * Get the formatted result list. Calls getStartBody(), formatRow() and
 317          * getEndBody(), concatenates the results and returns them.
 318          *
 319          * @return String
 320          */
 321         function getBody() {
 322                 if ( !$this->mQueryDone ) {
 323                         $this->doQuery();
 324                 }
 325                 # Don't use any extra rows returned by the query
 326                 $numRows = min( $this->mResult->numRows(), $this->mLimit );
 327
 328                 $s = $this->getStartBody();
 329                 if ( $numRows ) {
 330                         if ( $this->mIsBackwards ) {
 331                                 for ( $i = $numRows - 1; $i >= 0; $i-- ) {
 332                                         $this->mResult->seek( $i );
 333                                         $row = $this->mResult->fetchObject();
 334                                         $s .= $this->formatRow( $row );
 335                                 }
 336                         } else {
 337                                 $this->mResult->seek( 0 );
 338                                 for ( $i = 0; $i < $numRows; $i++ ) {
 339                                         $row = $this->mResult->fetchObject();
 340                                         $s .= $this->formatRow( $row );
 341                                 }
 342                         }
 343                 } else {
 344                         $s .= $this->getEmptyBody();
 345                 }
 346                 $s .= $this->getEndBody();
 347                 return $s;
 348         }
 349
 350         /**
 351          * Make a self-link
 352          *
 353          * @param $text String: text displayed on the link
 354          * @param $query Array: associative array of paramter to be in the query string
 355          * @param $type String: value of the "rel" attribute
 356          * @return String: HTML fragment
 357          */
 358         function makeLink($text, $query = null, $type=null) {
 359                 if ( $query === null ) {
 360                         return $text;
 361                 }
 362
 363                 $attrs = array();
 364                 if( in_array( $type, array( 'first', 'prev', 'next', 'last' ) ) ) {
 365                         # HTML5 rel attributes
 366                         $attrs['rel'] = $type;
 367                 }
 368
 369                 if( $type ) {
 370                         $attrs['class'] = "mw-{$type}link";
 371                 }
 372                 return Linker::linkKnown(
 373                         $this->getTitle(),
 374                         $text,
 375                         $attrs,
 376                         $query + $this->getDefaultQuery()
 377                 );
 378         }
 379
 380         /**
 381          * Hook into getBody(), allows text to be inserted at the start. This
 382          * will be called even if there are no rows in the result set.
 383          *
 384          * @return String
 385          */
 386         function getStartBody() {
 387                 return '';
 388         }
 389
 390         /**
 391          * Hook into getBody() for the end of the list
 392          *
 393          * @return String
 394          */
 395         function getEndBody() {
 396                 return '';
 397         }
 398
 399         /**
 400          * Hook into getBody(), for the bit between the start and the
 401          * end when there are no rows
 402          *
 403          * @return String
 404          */
 405         function getEmptyBody() {
 406                 return '';
 407         }
 408
 409         /**
 410          * Get an array of query parameters that should be put into self-links.
 411          * By default, all parameters passed in the URL are used, except for a
 412          * short blacklist.
 413          *
 414          * @return Associative array
 415          */
 416         function getDefaultQuery() {
 417                 if ( !isset( $this->mDefaultQuery ) ) {
 418                         $this->mDefaultQuery = $this->getRequest()->getQueryValues();
 419                         unset( $this->mDefaultQuery['title'] );
 420                         unset( $this->mDefaultQuery['dir'] );
 421                         unset( $this->mDefaultQuery['offset'] );
 422                         unset( $this->mDefaultQuery['limit'] );
 423                         unset( $this->mDefaultQuery['order'] );
 424                         unset( $this->mDefaultQuery['month'] );
 425                         unset( $this->mDefaultQuery['year'] );
 426                 }
 427                 return $this->mDefaultQuery;
 428         }
 429
 430         /**
 431          * Get the number of rows in the result set
 432          *
 433          * @return Integer
 434          */
 435         function getNumRows() {
 436                 if ( !$this->mQueryDone ) {
 437                         $this->doQuery();
 438                 }
 439                 return $this->mResult->numRows();
 440         }
 441
 442         /**
 443          * Get a URL query array for the prev, next, first and last links.
 444          *
 445          * @return Array
 446          */
 447         function getPagingQueries() {
 448                 if ( !$this->mQueryDone ) {
 449                         $this->doQuery();
 450                 }
 451
 452                 # Don't announce the limit everywhere if it's the default
 453                 $urlLimit = $this->mLimit == $this->mDefaultLimit ? '' : $this->mLimit;
 454
 455                 if ( $this->mIsFirst ) {
 456                         $prev = false;
 457                         $first = false;
 458                 } else {
 459                         $prev = array(
 460                                 'dir' => 'prev',
 461                                 'offset' => $this->mFirstShown,
 462                                 'limit' => $urlLimit
 463                         );
 464                         $first = array( 'limit' => $urlLimit );
 465                 }
 466                 if ( $this->mIsLast ) {
 467                         $next = false;
 468                         $last = false;
 469                 } else {
 470                         $next = array( 'offset' => $this->mLastShown, 'limit' => $urlLimit );
 471                         $last = array( 'dir' => 'prev', 'limit' => $urlLimit );
 472                 }
 473                 return array(
 474                         'prev' => $prev,
 475                         'next' => $next,
 476                         'first' => $first,
 477                         'last' => $last
 478                 );
 479         }
 480
 481         /**
 482          * Returns whether to show the "navigation bar"
 483          *
 484          * @return Boolean
 485          */
 486         function isNavigationBarShown() {
 487                 if ( !$this->mQueryDone ) {
 488                         $this->doQuery();
 489                 }
 490                 // Hide navigation by default if there is nothing to page
 491                 return !($this->mIsFirst && $this->mIsLast);
 492         }
 493
 494         /**
 495          * Get paging links. If a link is disabled, the item from $disabledTexts
 496          * will be used. If there is no such item, the unlinked text from
 497          * $linkTexts will be used. Both $linkTexts and $disabledTexts are arrays
 498          * of HTML.
 499          *
 500          * @return Array
 501          */
 502         function getPagingLinks( $linkTexts, $disabledTexts = array() ) {
 503                 $queries = $this->getPagingQueries();
 504                 $links = array();
 505                 foreach ( $queries as $type => $query ) {
 506                         if ( $query !== false ) {
 507                                 $links[$type] = $this->makeLink(
 508                                         $linkTexts[$type],
 509                                         $queries[$type],
 510                                         $type
 511                                 );
 512                         } elseif ( isset( $disabledTexts[$type] ) ) {
 513                                 $links[$type] = $disabledTexts[$type];
 514                         } else {
 515                                 $links[$type] = $linkTexts[$type];
 516                         }
 517                 }
 518                 return $links;
 519         }
 520
 521         function getLimitLinks() {
 522                 $links = array();
 523                 if ( $this->mIsBackwards ) {
 524                         $offset = $this->mPastTheEndIndex;
 525                 } else {
 526                         $offset = $this->mOffset;
 527                 }
 528                 foreach ( $this->mLimitsShown as $limit ) {
 529                         $links[] = $this->makeLink(
 530                                 $this->getLang()->formatNum( $limit ),
 531                                 array( 'offset' => $offset, 'limit' => $limit ),
 532                                 'num'
 533                         );
 534                 }
 535                 return $links;
 536         }
 537
 538         /**
 539          * Abstract formatting function. This should return an HTML string
 540          * representing the result row $row. Rows will be concatenated and
 541          * returned by getBody()
 542          *
 543          * @param $row Object: database row
 544          * @return String
 545          */
 546         abstract function formatRow( $row );
 547
 548         /**
 549          * This function should be overridden to provide all parameters
 550          * needed for the main paged query. It returns an associative
 551          * array with the following elements:
 552          *    tables => Table(s) for passing to Database::select()
 553          *    fields => Field(s) for passing to Database::select(), may be *
 554          *    conds => WHERE conditions
 555          *    options => option array
 556          *    join_conds => JOIN conditions
 557          *
 558          * @return Array
 559          */
 560         abstract function getQueryInfo();
 561
 562         /**
 563          * This function should be overridden to return the name of the index fi-
 564          * eld.  If the pager supports multiple orders, it may return an array of
 565          * 'querykey' => 'indexfield' pairs, so that a request with &count=querykey
 566          * will use indexfield to sort.  In this case, the first returned key is
 567          * the default.
 568          *
 569          * Needless to say, it's really not a good idea to use a non-unique index
 570          * for this!  That won't page right.
 571          *
 572          * @return string|Array
 573          */
 574         abstract function getIndexField();
 575
 576         /**
 577          * This function should be overridden to return the names of secondary columns
 578          * to order by in addition to the column in getIndexField(). These fields will
 579          * not be used in the pager offset or in any links for users.
 580          *
 581          * If getIndexField() returns an array of 'querykey' => 'indexfield' pairs then
 582          * this must return a corresponding array of 'querykey' => array( fields...) pairs
 583          * in order for a request with &count=querykey to use array( fields...) to sort.
 584          *
 585          * This is useful for pagers that GROUP BY a unique column (say page_id)
 586          * and ORDER BY another (say page_len). Using GROUP BY and ORDER BY both on
 587          * page_len,page_id avoids temp tables (given a page_len index). This would
 588          * also work if page_id was non-unique but we had a page_len,page_id index.
 589          *
 590          * @return Array
 591          */
 592         protected function getExtraSortFields() { return array(); }
 593
 594         /**
 595          * Return the default sorting direction: false for ascending, true for de-
 596          * scending.  You can also have an associative array of ordertype => dir,
 597          * if multiple order types are supported.  In this case getIndexField()
 598          * must return an array, and the keys of that must exactly match the keys
 599          * of this.
 600          *
 601          * For backward compatibility, this method's return value will be ignored
 602          * if $this->mDefaultDirection is already set when the constructor is
 603          * called, for instance if it's statically initialized.  In that case the
 604          * value of that variable (which must be a boolean) will be used.
 605          *
 606          * Note that despite its name, this does not return the value of the
 607          * $this->mDefaultDirection member variable.  That's the default for this
 608          * particular instantiation, which is a single value.  This is the set of
 609          * all defaults for the class.
 610          *
 611          * @return Boolean
 612          */
 613         protected function getDefaultDirections() { return false; }
 614 }
 615
 616
 617 /**
 618  * IndexPager with an alphabetic list and a formatted navigation bar
 619  * @ingroup Pager
 620  */
 621 abstract class AlphabeticPager extends IndexPager {
 622         /**
 623          * Shamelessly stolen bits from ReverseChronologicalPager,
 624          * didn't want to do class magic as may be still revamped
 625          */
 626         function getNavigationBar() {
 627                 if ( !$this->isNavigationBarShown() ) return '';
 628
 629                 if( isset( $this->mNavigationBar ) ) {
 630                         return $this->mNavigationBar;
 631                 }
 632
 633                 $lang = $this->getLang();
 634
 635                 $opts = array( 'parsemag', 'escapenoentities' );
 636                 $linkTexts = array(
 637                         'prev' => wfMsgExt(
 638                                 'prevn',
 639                                 $opts,
 640                                 $lang->formatNum( $this->mLimit )
 641                         ),
 642                         'next' => wfMsgExt(
 643                                 'nextn',
 644                                 $opts,
 645                                 $lang->formatNum($this->mLimit )
 646                         ),
 647                         'first' => wfMsgExt( 'page_first', $opts ),
 648                         'last' => wfMsgExt( 'page_last', $opts )
 649                 );
 650
 651                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 652                 $limitLinks = $this->getLimitLinks();
 653                 $limits = $lang->pipeList( $limitLinks );
 654
 655                 $this->mNavigationBar =
 656                         "(" . $lang->pipeList(
 657                                 array( $pagingLinks['first'],
 658                                 $pagingLinks['last'] )
 659                         ) . ") " .
 660                         wfMsgHtml( 'viewprevnext', $pagingLinks['prev'],
 661                         $pagingLinks['next'], $limits );
 662
 663                 if( !is_array( $this->getIndexField() ) ) {
 664                         # Early return to avoid undue nesting
 665                         return $this->mNavigationBar;
 666                 }
 667
 668                 $extra = '';
 669                 $first = true;
 670                 $msgs = $this->getOrderTypeMessages();
 671                 foreach( array_keys( $msgs ) as $order ) {
 672                         if( $first ) {
 673                                 $first = false;
 674                         } else {
 675                                 $extra .= wfMsgExt( 'pipe-separator' , 'escapenoentities' );
 676                         }
 677
 678                         if( $order == $this->mOrderType ) {
 679                                 $extra .= wfMsgHTML( $msgs[$order] );
 680                         } else {
 681                                 $extra .= $this->makeLink(
 682                                         wfMsgHTML( $msgs[$order] ),
 683                                         array( 'order' => $order )
 684                                 );
 685                         }
 686                 }
 687
 688                 if( $extra !== '' ) {
 689                         $this->mNavigationBar .= " ($extra)";
 690                 }
 691
 692                 return $this->mNavigationBar;
 693         }
 694
 695         /**
 696          * If this supports multiple order type messages, give the message key for
 697          * enabling each one in getNavigationBar.  The return type is an associa-
 698          * tive array whose keys must exactly match the keys of the array returned
 699          * by getIndexField(), and whose values are message keys.
 700          *
 701          * @return Array
 702          */
 703         protected function getOrderTypeMessages() {
 704                 return null;
 705         }
 706 }
 707
 708 /**
 709  * IndexPager with a formatted navigation bar
 710  * @ingroup Pager
 711  */
 712 abstract class ReverseChronologicalPager extends IndexPager {
 713         public $mDefaultDirection = true;
 714         public $mYear;
 715         public $mMonth;
 716
 717         function getNavigationBar() {
 718                 if ( !$this->isNavigationBarShown() ) {
 719                         return '';
 720                 }
 721
 722                 if ( isset( $this->mNavigationBar ) ) {
 723                         return $this->mNavigationBar;
 724                 }
 725
 726                 $nicenumber = $this->getLang()->formatNum( $this->mLimit );
 727                 $linkTexts = array(
 728                         'prev' => wfMsgExt(
 729                                 'pager-newer-n',
 730                                 array( 'parsemag', 'escape' ),
 731                                 $nicenumber
 732                         ),
 733                         'next' => wfMsgExt(
 734                                 'pager-older-n',
 735                                 array( 'parsemag', 'escape' ),
 736                                 $nicenumber
 737                         ),
 738                         'first' => wfMsgHtml( 'histlast' ),
 739                         'last' => wfMsgHtml( 'histfirst' )
 740                 );
 741
 742                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 743                 $limitLinks = $this->getLimitLinks();
 744                 $limits = $this->getLang()->pipeList( $limitLinks );
 745
 746                 $this->mNavigationBar = "({$pagingLinks['first']}" .
 747                         wfMsgExt( 'pipe-separator' , 'escapenoentities' ) .
 748                         "{$pagingLinks['last']}) " .
 749                         wfMsgHTML(
 750                                 'viewprevnext',
 751                                 $pagingLinks['prev'], $pagingLinks['next'],
 752                                 $limits
 753                         );
 754                 return $this->mNavigationBar;
 755         }
 756
 757         function getDateCond( $year, $month ) {
 758                 $year = intval($year);
 759                 $month = intval($month);
 760                 // Basic validity checks
 761                 $this->mYear = $year > 0 ? $year : false;
 762                 $this->mMonth = ($month > 0 && $month < 13) ? $month : false;
 763                 // Given an optional year and month, we need to generate a timestamp
 764                 // to use as "WHERE rev_timestamp <= result"
 765                 // Examples: year = 2006 equals < 20070101 (+000000)
 766                 // year=2005, month=1    equals < 20050201
 767                 // year=2005, month=12   equals < 20060101
 768                 if ( !$this->mYear && !$this->mMonth ) {
 769                         return;
 770                 }
 771                 if ( $this->mYear ) {
 772                         $year = $this->mYear;
 773                 } else {
 774                         // If no year given, assume the current one
 775                         $year = gmdate( 'Y' );
 776                         // If this month hasn't happened yet this year, go back to last year's month
 777                         if( $this->mMonth > gmdate( 'n' ) ) {
 778                                 $year--;
 779                         }
 780                 }
 781                 if ( $this->mMonth ) {
 782                         $month = $this->mMonth + 1;
 783                         // For December, we want January 1 of the next year
 784                         if ($month > 12) {
 785                                 $month = 1;
 786                                 $year++;
 787                         }
 788                 } else {
 789                         // No month implies we want up to the end of the year in question
 790                         $month = 1;
 791                         $year++;
 792                 }
 793                 // Y2K38 bug
 794                 if ( $year > 2032 ) {
 795                         $year = 2032;
 796                 }
 797                 $ymd = (int)sprintf( "%04d%02d01", $year, $month );
 798                 if ( $ymd > 20320101 ) {
 799                         $ymd = 20320101;
 800                 }
 801                 $this->mOffset = $this->mDb->timestamp( "${ymd}000000" );
 802         }
 803 }
 804
 805 /**
 806  * Table-based display with a user-selectable sort order
 807  * @ingroup Pager
 808  */
 809 abstract class TablePager extends IndexPager {
 810         var $mSort;
 811         var $mCurrentRow;
 812
 813         function __construct( RequestContext $context = null ) {
 814                 if ( $context ) {
 815                         $this->setContext( $context );
 816                 }
 817
 818                 $this->mSort = $this->getRequest()->getText( 'sort' );
 819                 if ( !array_key_exists( $this->mSort, $this->getFieldNames() ) ) {
 820                         $this->mSort = $this->getDefaultSort();
 821                 }
 822                 if ( $this->getRequest()->getBool( 'asc' ) ) {
 823                         $this->mDefaultDirection = false;
 824                 } elseif ( $this->getRequest()->getBool( 'desc' ) ) {
 825                         $this->mDefaultDirection = true;
 826                 } /* Else leave it at whatever the class default is */
 827
 828                 parent::__construct();
 829         }
 830
 831         function getStartBody() {
 832                 global $wgStylePath;
 833                 $tableClass = htmlspecialchars( $this->getTableClass() );
 834                 $sortClass = htmlspecialchars( $this->getSortHeaderClass() );
 835
 836                 $s = "<table style='border:1;' class=\"mw-datatable $tableClass\"><thead><tr>\n";
 837                 $fields = $this->getFieldNames();
 838
 839                 # Make table header
 840                 foreach ( $fields as $field => $name ) {
 841                         if ( strval( $name ) == '' ) {
 842                                 $s .= "<th>&#160;</th>\n";
 843                         } elseif ( $this->isFieldSortable( $field ) ) {
 844                                 $query = array( 'sort' => $field, 'limit' => $this->mLimit );
 845                                 if ( $field == $this->mSort ) {
 846                                         # This is the sorted column
 847                                         # Prepare a link that goes in the other sort order
 848                                         if ( $this->mDefaultDirection ) {
 849                                                 # Descending
 850                                                 $image = 'Arr_d.png';
 851                                                 $query['asc'] = '1';
 852                                                 $query['desc'] = '';
 853                                                 $alt = htmlspecialchars( wfMsg( 'descending_abbrev' ) );
 854                                         } else {
 855                                                 # Ascending
 856                                                 $image = 'Arr_u.png';
 857                                                 $query['asc'] = '';
 858                                                 $query['desc'] = '1';
 859                                                 $alt = htmlspecialchars( wfMsg( 'ascending_abbrev' ) );
 860                                         }
 861                                         $image = htmlspecialchars( "$wgStylePath/common/images/$image" );
 862                                         $link = $this->makeLink(
 863                                                 "<img width=\"12\" height=\"12\" alt=\"$alt\" src=\"$image\" />" .
 864                                                 htmlspecialchars( $name ), $query );
 865                                         $s .= "<th class=\"$sortClass\">$link</th>\n";
 866                                 } else {
 867                                         $s .= '<th>' . $this->makeLink( htmlspecialchars( $name ), $query ) . "</th>\n";
 868                                 }
 869                         } else {
 870                                 $s .= '<th>' . htmlspecialchars( $name ) . "</th>\n";
 871                         }
 872                 }
 873                 $s .= "</tr></thead><tbody>\n";
 874                 return $s;
 875         }
 876
 877         function getEndBody() {
 878                 return "</tbody></table>\n";
 879         }
 880
 881         function getEmptyBody() {
 882                 $colspan = count( $this->getFieldNames() );
 883                 $msgEmpty = wfMsgHtml( 'table_pager_empty' );
 884                 return "<tr><td colspan=\"$colspan\">$msgEmpty</td></tr>\n";
 885         }
 886
 887         function formatRow( $row ) {
 888                 $this->mCurrentRow = $row;      # In case formatValue etc need to know
 889                 $s = Xml::openElement( 'tr', $this->getRowAttrs($row) );
 890                 $fieldNames = $this->getFieldNames();
 891                 foreach ( $fieldNames as $field => $name ) {
 892                         $value = isset( $row->$field ) ? $row->$field : null;
 893                         $formatted = strval( $this->formatValue( $field, $value ) );
 894                         if ( $formatted == '' ) {
 895                                 $formatted = '&#160;';
 896                         }
 897                         $s .= Xml::tags( 'td', $this->getCellAttrs( $field, $value ), $formatted );
 898                 }
 899                 $s .= "</tr>\n";
 900                 return $s;
 901         }
 902
 903         /**
 904          * Get a class name to be applied to the given row.
 905          *
 906          * @param $row Object: the database result row
 907          * @return String
 908          */
 909         function getRowClass( $row ) {
 910                 return '';
 911         }
 912
 913         /**
 914          * Get attributes to be applied to the given row.
 915          *
 916          * @param $row Object: the database result row
 917          * @return Associative array
 918          */
 919         function getRowAttrs( $row ) {
 920                 $class = $this->getRowClass( $row );
 921                 if ( $class === '' ) {
 922                         // Return an empty array to avoid clutter in HTML like class=""
 923                         return array();
 924                 } else {
 925                         return array( 'class' => $this->getRowClass( $row ) );
 926                 }
 927         }
 928
 929         /**
 930          * Get any extra attributes to be applied to the given cell. Don't
 931          * take this as an excuse to hardcode styles; use classes and
 932          * CSS instead.  Row context is available in $this->mCurrentRow
 933          *
 934          * @param $field The column
 935          * @param $value The cell contents
 936          * @return Associative array
 937          */
 938         function getCellAttrs( $field, $value ) {
 939                 return array( 'class' => 'TablePager_col_' . $field );
 940         }
 941
 942         function getIndexField() {
 943                 return $this->mSort;
 944         }
 945
 946         function getTableClass() {
 947                 return 'TablePager';
 948         }
 949
 950         function getNavClass() {
 951                 return 'TablePager_nav';
 952         }
 953
 954         function getSortHeaderClass() {
 955                 return 'TablePager_sort';
 956         }
 957
 958         /**
 959          * A navigation bar with images
 960          */
 961         function getNavigationBar() {
 962                 global $wgStylePath;
 963
 964                 if ( !$this->isNavigationBarShown() ) {
 965                         return '';
 966                 }
 967
 968                 $path = "$wgStylePath/common/images";
 969                 $labels = array(
 970                         'first' => 'table_pager_first',
 971                         'prev' => 'table_pager_prev',
 972                         'next' => 'table_pager_next',
 973                         'last' => 'table_pager_last',
 974                 );
 975                 $images = array(
 976                         'first' => 'arrow_first_25.png',
 977                         'prev' => 'arrow_left_25.png',
 978                         'next' => 'arrow_right_25.png',
 979                         'last' => 'arrow_last_25.png',
 980                 );
 981                 $disabledImages = array(
 982                         'first' => 'arrow_disabled_first_25.png',
 983                         'prev' => 'arrow_disabled_left_25.png',
 984                         'next' => 'arrow_disabled_right_25.png',
 985                         'last' => 'arrow_disabled_last_25.png',
 986                 );
 987                 if( $this->getLang()->isRTL() ) {
 988                         $keys = array_keys( $labels );
 989                         $images = array_combine( $keys, array_reverse( $images ) );
 990                         $disabledImages = array_combine( $keys, array_reverse( $disabledImages ) );
 991                 }
 992
 993                 $linkTexts = array();
 994                 $disabledTexts = array();
 995                 foreach ( $labels as $type => $label ) {
 996                         $msgLabel = wfMsgHtml( $label );
 997                         $linkTexts[$type] = "<img src=\"$path/{$images[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
 998                         $disabledTexts[$type] = "<img src=\"$path/{$disabledImages[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
 999                 }
1000                 $links = $this->getPagingLinks( $linkTexts, $disabledTexts );
1001
1002                 $navClass = htmlspecialchars( $this->getNavClass() );
1003                 $s = "<table class=\"$navClass\"><tr>\n";
1004                 $width = 100 / count( $links ) . '%';
1005                 foreach ( $labels as $type => $label ) {
1006                         $s .= "<td style='width:$width;'>{$links[$type]}</td>\n";
1007                 }
1008                 $s .= "</tr></table>\n";
1009                 return $s;
1010         }
1011
1012         /**
1013          * Get a <select> element which has options for each of the allowed limits
1014          *
1015          * @return String: HTML fragment
1016          */
1017         function getLimitSelect() {
1018                 # Add the current limit from the query string
1019                 # to avoid that the limit is lost after clicking Go next time
1020                 if ( !in_array( $this->mLimit, $this->mLimitsShown ) ) {
1021                         $this->mLimitsShown[] = $this->mLimit;
1022                         sort( $this->mLimitsShown );
1023                 }
1024                 $s = Html::openElement( 'select', array( 'name' => 'limit' ) ) . "\n";
1025                 foreach ( $this->mLimitsShown as $key => $value ) {
1026                         # The pair is either $index => $limit, in which case the $value
1027                         # will be numeric, or $limit => $text, in which case the $value
1028                         # will be a string.
1029                         if( is_int( $value ) ){
1030                                 $limit = $value;
1031                                 $text = $this->getLang()->formatNum( $limit );
1032                         } else {
1033                                 $limit = $key;
1034                                 $text = $value;
1035                         }
1036                         $s .= Xml::option( $text, $limit, $limit == $this->mLimit ) . "\n";
1037                 }
1038                 $s .= Html::closeElement( 'select' );
1039                 return $s;
1040         }
1041
1042         /**
1043          * Get <input type="hidden"> elements for use in a method="get" form.
1044          * Resubmits all defined elements of the query string, except for a
1045          * blacklist, passed in the $blacklist parameter.
1046          *
1047          * @return String: HTML fragment
1048          */
1049         function getHiddenFields( $blacklist = array() ) {
1050                 $blacklist = (array)$blacklist;
1051                 $query = $this->getRequest()->getQueryValues();
1052                 foreach ( $blacklist as $name ) {
1053                         unset( $query[$name] );
1054                 }
1055                 $s = '';
1056                 foreach ( $query as $name => $value ) {
1057                         $encName = htmlspecialchars( $name );
1058                         $encValue = htmlspecialchars( $value );
1059                         $s .= "<input type=\"hidden\" name=\"$encName\" value=\"$encValue\"/>\n";
1060                 }
1061                 return $s;
1062         }
1063
1064         /**
1065          * Get a form containing a limit selection dropdown
1066          *
1067          * @return String: HTML fragment
1068          */
1069         function getLimitForm() {
1070                 global $wgScript;
1071
1072                 return Xml::openElement(
1073                         'form',
1074                         array(
1075                                 'method' => 'get',
1076                                 'action' => $wgScript
1077                         ) ) . "\n" . $this->getLimitDropdown() . "</form>\n";
1078         }
1079
1080         /**
1081          * Gets a limit selection dropdown
1082          *
1083          * @return string
1084          */
1085         function getLimitDropdown() {
1086                 # Make the select with some explanatory text
1087                 $msgSubmit = wfMsgHtml( 'table_pager_limit_submit' );
1088
1089                 return wfMsgHtml( 'table_pager_limit', $this->getLimitSelect() ) .
1090                         "\n<input type=\"submit\" value=\"$msgSubmit\"/>\n" .
1091                         $this->getHiddenFields( array( 'limit' ) );
1092         }
1093
1094         /**
1095          * Return true if the named field should be sortable by the UI, false
1096          * otherwise
1097          *
1098          * @param $field String
1099          */
1100         abstract function isFieldSortable( $field );
1101
1102         /**
1103          * Format a table cell. The return value should be HTML, but use an empty
1104          * string not &#160; for empty cells. Do not include the <td> and </td>.
1105          *
1106          * The current result row is available as $this->mCurrentRow, in case you
1107          * need more context.
1108          *
1109          * @param $name String: the database field name
1110          * @param $value String: the value retrieved from the database
1111          */
1112         abstract function formatValue( $name, $value );
1113
1114         /**
1115          * The database field name used as a default sort order
1116          */
1117         abstract function getDefaultSort();
1118
1119         /**
1120          * An array mapping database field names to a textual description of the
1121          * field name, for use in the table header. The description should be plain
1122          * text, it will be HTML-escaped later.
1123          */
1124         abstract function getFieldNames();
1125 }