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         public $mIsLast;
  99
 100         protected $mLastShown, $mFirstShown, $mPastTheEndIndex, $mDefaultQuery, $mNavigationBar;
 101
 102         /**
 103          * Result object for the query. Warning: seek before use.
 104          *
 105          * @var ResultWrapper
 106          */
 107         public $mResult;
 108
 109         public function __construct( IContextSource $context = null ) {
 110                 if ( $context ) {
 111                         $this->setContext( $context );
 112                 }
 113
 114                 $this->mRequest = $this->getRequest();
 115
 116                 # NB: the offset is quoted, not validated. It is treated as an
 117                 # arbitrary string to support the widest variety of index types. Be
 118                 # careful outputting it into HTML!
 119                 $this->mOffset = $this->mRequest->getText( 'offset' );
 120
 121                 # Use consistent behavior for the limit options
 122                 $this->mDefaultLimit = intval( $this->getUser()->getOption( 'rclimit' ) );
 123                 list( $this->mLimit, /* $offset */ ) = $this->mRequest->getLimitOffset();
 124
 125                 $this->mIsBackwards = ( $this->mRequest->getVal( 'dir' ) == 'prev' );
 126                 $this->mDb = wfGetDB( DB_SLAVE );
 127
 128                 $index = $this->getIndexField(); // column to sort on
 129                 $extraSort = $this->getExtraSortFields(); // extra columns to sort on for query planning
 130                 $order = $this->mRequest->getVal( 'order' );
 131                 if( is_array( $index ) && isset( $index[$order] ) ) {
 132                         $this->mOrderType = $order;
 133                         $this->mIndexField = $index[$order];
 134                         $this->mExtraSortFields = isset( $extraSort[$order] )
 135                                 ? (array)$extraSort[$order]
 136                                 : array();
 137                 } elseif( is_array( $index ) ) {
 138                         # First element is the default
 139                         reset( $index );
 140                         list( $this->mOrderType, $this->mIndexField ) = each( $index );
 141                         $this->mExtraSortFields = isset( $extraSort[$this->mOrderType] )
 142                                 ? (array)$extraSort[$this->mOrderType]
 143                                 : array();
 144                 } else {
 145                         # $index is not an array
 146                         $this->mOrderType = null;
 147                         $this->mIndexField = $index;
 148                         $this->mExtraSortFields = (array)$extraSort;
 149                 }
 150
 151                 if( !isset( $this->mDefaultDirection ) ) {
 152                         $dir = $this->getDefaultDirections();
 153                         $this->mDefaultDirection = is_array( $dir )
 154                                 ? $dir[$this->mOrderType]
 155                                 : $dir;
 156                 }
 157         }
 158
 159         /**
 160          * Do the query, using information from the object context. This function
 161          * has been kept minimal to make it overridable if necessary, to allow for
 162          * result sets formed from multiple DB queries.
 163          */
 164         public function doQuery() {
 165                 # Use the child class name for profiling
 166                 $fname = __METHOD__ . ' (' . get_class( $this ) . ')';
 167                 wfProfileIn( $fname );
 168
 169                 $descending = ( $this->mIsBackwards == $this->mDefaultDirection );
 170                 # Plus an extra row so that we can tell the "next" link should be shown
 171                 $queryLimit = $this->mLimit + 1;
 172
 173                 $this->mResult = $this->reallyDoQuery(
 174                         $this->mOffset,
 175                         $queryLimit,
 176                         $descending
 177                 );
 178                 $this->extractResultInfo( $this->mOffset, $queryLimit, $this->mResult );
 179                 $this->mQueryDone = true;
 180
 181                 $this->preprocessResults( $this->mResult );
 182                 $this->mResult->rewind(); // Paranoia
 183
 184                 wfProfileOut( $fname );
 185         }
 186
 187         /**
 188          * @return ResultWrapper The result wrapper.
 189          */
 190         function getResult() {
 191                 return $this->mResult;
 192         }
 193
 194         /**
 195          * Set the offset from an other source than the request
 196          *
 197          * @param $offset Int|String
 198          */
 199         function setOffset( $offset ) {
 200                 $this->mOffset = $offset;
 201         }
 202         /**
 203          * Set the limit from an other source than the request
 204          *
 205          * @param $limit Int|String
 206          */
 207         function setLimit( $limit ) {
 208                 $this->mLimit = $limit;
 209         }
 210
 211         /**
 212          * Extract some useful data from the result object for use by
 213          * the navigation bar, put it into $this
 214          *
 215          * @param $offset String: index offset, inclusive
 216          * @param $limit Integer: exact query limit
 217          * @param $res ResultWrapper
 218          */
 219         function extractResultInfo( $offset, $limit, ResultWrapper $res ) {
 220                 $numRows = $res->numRows();
 221                 if ( $numRows ) {
 222                         # Remove any table prefix from index field
 223                         $parts = explode( '.', $this->mIndexField );
 224                         $indexColumn = end( $parts );
 225
 226                         $row = $res->fetchRow();
 227                         $firstIndex = $row[$indexColumn];
 228
 229                         # Discard the extra result row if there is one
 230                         if ( $numRows > $this->mLimit && $numRows > 1 ) {
 231                                 $res->seek( $numRows - 1 );
 232                                 $this->mPastTheEndRow = $res->fetchObject();
 233                                 $indexField = $this->mIndexField;
 234                                 $this->mPastTheEndIndex = $this->mPastTheEndRow->$indexField;
 235                                 $res->seek( $numRows - 2 );
 236                                 $row = $res->fetchRow();
 237                                 $lastIndex = $row[$indexColumn];
 238                         } else {
 239                                 $this->mPastTheEndRow = null;
 240                                 # Setting indexes to an empty string means that they will be
 241                                 # omitted if they would otherwise appear in URLs. It just so
 242                                 # happens that this  is the right thing to do in the standard
 243                                 # UI, in all the relevant cases.
 244                                 $this->mPastTheEndIndex = '';
 245                                 $res->seek( $numRows - 1 );
 246                                 $row = $res->fetchRow();
 247                                 $lastIndex = $row[$indexColumn];
 248                         }
 249                 } else {
 250                         $firstIndex = '';
 251                         $lastIndex = '';
 252                         $this->mPastTheEndRow = null;
 253                         $this->mPastTheEndIndex = '';
 254                 }
 255
 256                 if ( $this->mIsBackwards ) {
 257                         $this->mIsFirst = ( $numRows < $limit );
 258                         $this->mIsLast = ( $offset == '' );
 259                         $this->mLastShown = $firstIndex;
 260                         $this->mFirstShown = $lastIndex;
 261                 } else {
 262                         $this->mIsFirst = ( $offset == '' );
 263                         $this->mIsLast = ( $numRows < $limit );
 264                         $this->mLastShown = $lastIndex;
 265                         $this->mFirstShown = $firstIndex;
 266                 }
 267         }
 268
 269         /**
 270          * Get some text to go in brackets in the "function name" part of the SQL comment
 271          *
 272          * @return String
 273          */
 274         function getSqlComment() {
 275                 return get_class( $this );
 276         }
 277
 278         /**
 279          * Do a query with specified parameters, rather than using the object
 280          * context
 281          *
 282          * @param $offset String: index offset, inclusive
 283          * @param $limit Integer: exact query limit
 284          * @param $descending Boolean: query direction, false for ascending, true for descending
 285          * @return ResultWrapper
 286          */
 287         function reallyDoQuery( $offset, $limit, $descending ) {
 288                 $fname = __METHOD__ . ' (' . $this->getSqlComment() . ')';
 289                 $info = $this->getQueryInfo();
 290                 $tables = $info['tables'];
 291                 $fields = $info['fields'];
 292                 $conds = isset( $info['conds'] ) ? $info['conds'] : array();
 293                 $options = isset( $info['options'] ) ? $info['options'] : array();
 294                 $join_conds = isset( $info['join_conds'] ) ? $info['join_conds'] : array();
 295                 $sortColumns = array_merge( array( $this->mIndexField ), $this->mExtraSortFields );
 296                 if ( $descending ) {
 297                         $options['ORDER BY'] = implode( ',', $sortColumns );
 298                         $operator = '>';
 299                 } else {
 300                         $orderBy = array();
 301                         foreach ( $sortColumns as $col ) {
 302                                 $orderBy[] = $col . ' DESC';
 303                         }
 304                         $options['ORDER BY'] = implode( ',', $orderBy );
 305                         $operator = '<';
 306                 }
 307                 if ( $offset != '' ) {
 308                         $conds[] = $this->mIndexField . $operator . $this->mDb->addQuotes( $offset );
 309                 }
 310                 $options['LIMIT'] = intval( $limit );
 311                 $res = $this->mDb->select( $tables, $fields, $conds, $fname, $options, $join_conds );
 312                 return new ResultWrapper( $this->mDb, $res );
 313         }
 314
 315         /**
 316          * Pre-process results; useful for performing batch existence checks, etc.
 317          *
 318          * @param $result ResultWrapper
 319          */
 320         protected function preprocessResults( $result ) {}
 321
 322         /**
 323          * Get the formatted result list. Calls getStartBody(), formatRow() and
 324          * getEndBody(), concatenates the results and returns them.
 325          *
 326          * @return String
 327          */
 328         public function getBody() {
 329                 if ( !$this->mQueryDone ) {
 330                         $this->doQuery();
 331                 }
 332                 # Do any special query batches before display
 333                 $this->doBatchLookups();
 334
 335                 # Don't use any extra rows returned by the query
 336                 $numRows = min( $this->mResult->numRows(), $this->mLimit );
 337
 338                 $s = $this->getStartBody();
 339                 if ( $numRows ) {
 340                         if ( $this->mIsBackwards ) {
 341                                 for ( $i = $numRows - 1; $i >= 0; $i-- ) {
 342                                         $this->mResult->seek( $i );
 343                                         $row = $this->mResult->fetchObject();
 344                                         $s .= $this->formatRow( $row );
 345                                 }
 346                         } else {
 347                                 $this->mResult->seek( 0 );
 348                                 for ( $i = 0; $i < $numRows; $i++ ) {
 349                                         $row = $this->mResult->fetchObject();
 350                                         $s .= $this->formatRow( $row );
 351                                 }
 352                         }
 353                 } else {
 354                         $s .= $this->getEmptyBody();
 355                 }
 356                 $s .= $this->getEndBody();
 357                 return $s;
 358         }
 359
 360         /**
 361          * Make a self-link
 362          *
 363          * @param $text String: text displayed on the link
 364          * @param $query Array: associative array of paramter to be in the query string
 365          * @param $type String: value of the "rel" attribute
 366          * @return String: HTML fragment
 367          */
 368         function makeLink($text, $query = null, $type=null) {
 369                 if ( $query === null ) {
 370                         return $text;
 371                 }
 372
 373                 $attrs = array();
 374                 if( in_array( $type, array( 'first', 'prev', 'next', 'last' ) ) ) {
 375                         # HTML5 rel attributes
 376                         $attrs['rel'] = $type;
 377                 }
 378
 379                 if( $type ) {
 380                         $attrs['class'] = "mw-{$type}link";
 381                 }
 382                 return Linker::linkKnown(
 383                         $this->getTitle(),
 384                         $text,
 385                         $attrs,
 386                         $query + $this->getDefaultQuery()
 387                 );
 388         }
 389
 390         /**
 391          * Called from getBody(), before getStartBody() is called and
 392          * after doQuery() was called. This will be called even if there
 393          * are no rows in the result set.
 394          *
 395          * @return void
 396          */
 397         protected function doBatchLookups() {}
 398
 399         /**
 400          * Hook into getBody(), allows text to be inserted at the start. This
 401          * will be called even if there are no rows in the result set.
 402          *
 403          * @return String
 404          */
 405         protected function getStartBody() {
 406                 return '';
 407         }
 408
 409         /**
 410          * Hook into getBody() for the end of the list
 411          *
 412          * @return String
 413          */
 414         protected function getEndBody() {
 415                 return '';
 416         }
 417
 418         /**
 419          * Hook into getBody(), for the bit between the start and the
 420          * end when there are no rows
 421          *
 422          * @return String
 423          */
 424         protected function getEmptyBody() {
 425                 return '';
 426         }
 427
 428         /**
 429          * Get an array of query parameters that should be put into self-links.
 430          * By default, all parameters passed in the URL are used, except for a
 431          * short blacklist.
 432          *
 433          * @return Associative array
 434          */
 435         function getDefaultQuery() {
 436                 if ( !isset( $this->mDefaultQuery ) ) {
 437                         $this->mDefaultQuery = $this->getRequest()->getQueryValues();
 438                         unset( $this->mDefaultQuery['title'] );
 439                         unset( $this->mDefaultQuery['dir'] );
 440                         unset( $this->mDefaultQuery['offset'] );
 441                         unset( $this->mDefaultQuery['limit'] );
 442                         unset( $this->mDefaultQuery['order'] );
 443                         unset( $this->mDefaultQuery['month'] );
 444                         unset( $this->mDefaultQuery['year'] );
 445                 }
 446                 return $this->mDefaultQuery;
 447         }
 448
 449         /**
 450          * Get the number of rows in the result set
 451          *
 452          * @return Integer
 453          */
 454         function getNumRows() {
 455                 if ( !$this->mQueryDone ) {
 456                         $this->doQuery();
 457                 }
 458                 return $this->mResult->numRows();
 459         }
 460
 461         /**
 462          * Get a URL query array for the prev, next, first and last links.
 463          *
 464          * @return Array
 465          */
 466         function getPagingQueries() {
 467                 if ( !$this->mQueryDone ) {
 468                         $this->doQuery();
 469                 }
 470
 471                 # Don't announce the limit everywhere if it's the default
 472                 $urlLimit = $this->mLimit == $this->mDefaultLimit ? '' : $this->mLimit;
 473
 474                 if ( $this->mIsFirst ) {
 475                         $prev = false;
 476                         $first = false;
 477                 } else {
 478                         $prev = array(
 479                                 'dir' => 'prev',
 480                                 'offset' => $this->mFirstShown,
 481                                 'limit' => $urlLimit
 482                         );
 483                         $first = array( 'limit' => $urlLimit );
 484                 }
 485                 if ( $this->mIsLast ) {
 486                         $next = false;
 487                         $last = false;
 488                 } else {
 489                         $next = array( 'offset' => $this->mLastShown, 'limit' => $urlLimit );
 490                         $last = array( 'dir' => 'prev', 'limit' => $urlLimit );
 491                 }
 492                 return array(
 493                         'prev' => $prev,
 494                         'next' => $next,
 495                         'first' => $first,
 496                         'last' => $last
 497                 );
 498         }
 499
 500         /**
 501          * Returns whether to show the "navigation bar"
 502          *
 503          * @return Boolean
 504          */
 505         function isNavigationBarShown() {
 506                 if ( !$this->mQueryDone ) {
 507                         $this->doQuery();
 508                 }
 509                 // Hide navigation by default if there is nothing to page
 510                 return !($this->mIsFirst && $this->mIsLast);
 511         }
 512
 513         /**
 514          * Get paging links. If a link is disabled, the item from $disabledTexts
 515          * will be used. If there is no such item, the unlinked text from
 516          * $linkTexts will be used. Both $linkTexts and $disabledTexts are arrays
 517          * of HTML.
 518          *
 519          * @param $linkTexts Array
 520          * @param $disabledTexts Array
 521          * @return Array
 522          */
 523         function getPagingLinks( $linkTexts, $disabledTexts = array() ) {
 524                 $queries = $this->getPagingQueries();
 525                 $links = array();
 526                 foreach ( $queries as $type => $query ) {
 527                         if ( $query !== false ) {
 528                                 $links[$type] = $this->makeLink(
 529                                         $linkTexts[$type],
 530                                         $queries[$type],
 531                                         $type
 532                                 );
 533                         } elseif ( isset( $disabledTexts[$type] ) ) {
 534                                 $links[$type] = $disabledTexts[$type];
 535                         } else {
 536                                 $links[$type] = $linkTexts[$type];
 537                         }
 538                 }
 539                 return $links;
 540         }
 541
 542         function getLimitLinks() {
 543                 $links = array();
 544                 if ( $this->mIsBackwards ) {
 545                         $offset = $this->mPastTheEndIndex;
 546                 } else {
 547                         $offset = $this->mOffset;
 548                 }
 549                 foreach ( $this->mLimitsShown as $limit ) {
 550                         $links[] = $this->makeLink(
 551                                 $this->getLang()->formatNum( $limit ),
 552                                 array( 'offset' => $offset, 'limit' => $limit ),
 553                                 'num'
 554                         );
 555                 }
 556                 return $links;
 557         }
 558
 559         /**
 560          * Abstract formatting function. This should return an HTML string
 561          * representing the result row $row. Rows will be concatenated and
 562          * returned by getBody()
 563          *
 564          * @param $row Object: database row
 565          * @return String
 566          */
 567         abstract function formatRow( $row );
 568
 569         /**
 570          * This function should be overridden to provide all parameters
 571          * needed for the main paged query. It returns an associative
 572          * array with the following elements:
 573          *    tables => Table(s) for passing to Database::select()
 574          *    fields => Field(s) for passing to Database::select(), may be *
 575          *    conds => WHERE conditions
 576          *    options => option array
 577          *    join_conds => JOIN conditions
 578          *
 579          * @return Array
 580          */
 581         abstract function getQueryInfo();
 582
 583         /**
 584          * This function should be overridden to return the name of the index fi-
 585          * eld.  If the pager supports multiple orders, it may return an array of
 586          * 'querykey' => 'indexfield' pairs, so that a request with &count=querykey
 587          * will use indexfield to sort.  In this case, the first returned key is
 588          * the default.
 589          *
 590          * Needless to say, it's really not a good idea to use a non-unique index
 591          * for this!  That won't page right.
 592          *
 593          * @return string|Array
 594          */
 595         abstract function getIndexField();
 596
 597         /**
 598          * This function should be overridden to return the names of secondary columns
 599          * to order by in addition to the column in getIndexField(). These fields will
 600          * not be used in the pager offset or in any links for users.
 601          *
 602          * If getIndexField() returns an array of 'querykey' => 'indexfield' pairs then
 603          * this must return a corresponding array of 'querykey' => array( fields...) pairs
 604          * in order for a request with &count=querykey to use array( fields...) to sort.
 605          *
 606          * This is useful for pagers that GROUP BY a unique column (say page_id)
 607          * and ORDER BY another (say page_len). Using GROUP BY and ORDER BY both on
 608          * page_len,page_id avoids temp tables (given a page_len index). This would
 609          * also work if page_id was non-unique but we had a page_len,page_id index.
 610          *
 611          * @return Array
 612          */
 613         protected function getExtraSortFields() { return array(); }
 614
 615         /**
 616          * Return the default sorting direction: false for ascending, true for de-
 617          * scending.  You can also have an associative array of ordertype => dir,
 618          * if multiple order types are supported.  In this case getIndexField()
 619          * must return an array, and the keys of that must exactly match the keys
 620          * of this.
 621          *
 622          * For backward compatibility, this method's return value will be ignored
 623          * if $this->mDefaultDirection is already set when the constructor is
 624          * called, for instance if it's statically initialized.  In that case the
 625          * value of that variable (which must be a boolean) will be used.
 626          *
 627          * Note that despite its name, this does not return the value of the
 628          * $this->mDefaultDirection member variable.  That's the default for this
 629          * particular instantiation, which is a single value.  This is the set of
 630          * all defaults for the class.
 631          *
 632          * @return Boolean
 633          */
 634         protected function getDefaultDirections() { return false; }
 635 }
 636
 637
 638 /**
 639  * IndexPager with an alphabetic list and a formatted navigation bar
 640  * @ingroup Pager
 641  */
 642 abstract class AlphabeticPager extends IndexPager {
 643
 644         /**
 645          * Shamelessly stolen bits from ReverseChronologicalPager,
 646          * didn't want to do class magic as may be still revamped
 647          *
 648          * @return String HTML
 649          */
 650         function getNavigationBar() {
 651                 if ( !$this->isNavigationBarShown() ) return '';
 652
 653                 if( isset( $this->mNavigationBar ) ) {
 654                         return $this->mNavigationBar;
 655                 }
 656
 657                 $lang = $this->getLang();
 658
 659                 $opts = array( 'parsemag', 'escapenoentities' );
 660                 $linkTexts = array(
 661                         'prev' => wfMsgExt(
 662                                 'prevn',
 663                                 $opts,
 664                                 $lang->formatNum( $this->mLimit )
 665                         ),
 666                         'next' => wfMsgExt(
 667                                 'nextn',
 668                                 $opts,
 669                                 $lang->formatNum($this->mLimit )
 670                         ),
 671                         'first' => wfMsgExt( 'page_first', $opts ),
 672                         'last' => wfMsgExt( 'page_last', $opts )
 673                 );
 674
 675                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 676                 $limitLinks = $this->getLimitLinks();
 677                 $limits = $lang->pipeList( $limitLinks );
 678
 679                 $this->mNavigationBar =
 680                         "(" . $lang->pipeList(
 681                                 array( $pagingLinks['first'],
 682                                 $pagingLinks['last'] )
 683                         ) . ") " .
 684                         wfMsgHtml( 'viewprevnext', $pagingLinks['prev'],
 685                         $pagingLinks['next'], $limits );
 686
 687                 if( !is_array( $this->getIndexField() ) ) {
 688                         # Early return to avoid undue nesting
 689                         return $this->mNavigationBar;
 690                 }
 691
 692                 $extra = '';
 693                 $first = true;
 694                 $msgs = $this->getOrderTypeMessages();
 695                 foreach( array_keys( $msgs ) as $order ) {
 696                         if( $first ) {
 697                                 $first = false;
 698                         } else {
 699                                 $extra .= wfMsgExt( 'pipe-separator' , 'escapenoentities' );
 700                         }
 701
 702                         if( $order == $this->mOrderType ) {
 703                                 $extra .= wfMsgHTML( $msgs[$order] );
 704                         } else {
 705                                 $extra .= $this->makeLink(
 706                                         wfMsgHTML( $msgs[$order] ),
 707                                         array( 'order' => $order )
 708                                 );
 709                         }
 710                 }
 711
 712                 if( $extra !== '' ) {
 713                         $this->mNavigationBar .= " ($extra)";
 714                 }
 715
 716                 return $this->mNavigationBar;
 717         }
 718
 719         /**
 720          * If this supports multiple order type messages, give the message key for
 721          * enabling each one in getNavigationBar.  The return type is an associa-
 722          * tive array whose keys must exactly match the keys of the array returned
 723          * by getIndexField(), and whose values are message keys.
 724          *
 725          * @return Array
 726          */
 727         protected function getOrderTypeMessages() {
 728                 return null;
 729         }
 730 }
 731
 732 /**
 733  * IndexPager with a formatted navigation bar
 734  * @ingroup Pager
 735  */
 736 abstract class ReverseChronologicalPager extends IndexPager {
 737         public $mDefaultDirection = true;
 738         public $mYear;
 739         public $mMonth;
 740
 741         function getNavigationBar() {
 742                 if ( !$this->isNavigationBarShown() ) {
 743                         return '';
 744                 }
 745
 746                 if ( isset( $this->mNavigationBar ) ) {
 747                         return $this->mNavigationBar;
 748                 }
 749
 750                 $nicenumber = $this->getLang()->formatNum( $this->mLimit );
 751                 $linkTexts = array(
 752                         'prev' => wfMsgExt(
 753                                 'pager-newer-n',
 754                                 array( 'parsemag', 'escape' ),
 755                                 $nicenumber
 756                         ),
 757                         'next' => wfMsgExt(
 758                                 'pager-older-n',
 759                                 array( 'parsemag', 'escape' ),
 760                                 $nicenumber
 761                         ),
 762                         'first' => wfMsgHtml( 'histlast' ),
 763                         'last' => wfMsgHtml( 'histfirst' )
 764                 );
 765
 766                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 767                 $limitLinks = $this->getLimitLinks();
 768                 $limits = $this->getLang()->pipeList( $limitLinks );
 769
 770                 $this->mNavigationBar = "({$pagingLinks['first']}" .
 771                         wfMsgExt( 'pipe-separator' , 'escapenoentities' ) .
 772                         "{$pagingLinks['last']}) " .
 773                         wfMsgHTML(
 774                                 'viewprevnext',
 775                                 $pagingLinks['prev'], $pagingLinks['next'],
 776                                 $limits
 777                         );
 778                 return $this->mNavigationBar;
 779         }
 780
 781         function getDateCond( $year, $month ) {
 782                 $year = intval($year);
 783                 $month = intval($month);
 784                 // Basic validity checks
 785                 $this->mYear = $year > 0 ? $year : false;
 786                 $this->mMonth = ($month > 0 && $month < 13) ? $month : false;
 787                 // Given an optional year and month, we need to generate a timestamp
 788                 // to use as "WHERE rev_timestamp <= result"
 789                 // Examples: year = 2006 equals < 20070101 (+000000)
 790                 // year=2005, month=1    equals < 20050201
 791                 // year=2005, month=12   equals < 20060101
 792                 if ( !$this->mYear && !$this->mMonth ) {
 793                         return;
 794                 }
 795                 if ( $this->mYear ) {
 796                         $year = $this->mYear;
 797                 } else {
 798                         // If no year given, assume the current one
 799                         $year = gmdate( 'Y' );
 800                         // If this month hasn't happened yet this year, go back to last year's month
 801                         if( $this->mMonth > gmdate( 'n' ) ) {
 802                                 $year--;
 803                         }
 804                 }
 805                 if ( $this->mMonth ) {
 806                         $month = $this->mMonth + 1;
 807                         // For December, we want January 1 of the next year
 808                         if ($month > 12) {
 809                                 $month = 1;
 810                                 $year++;
 811                         }
 812                 } else {
 813                         // No month implies we want up to the end of the year in question
 814                         $month = 1;
 815                         $year++;
 816                 }
 817                 // Y2K38 bug
 818                 if ( $year > 2032 ) {
 819                         $year = 2032;
 820                 }
 821                 $ymd = (int)sprintf( "%04d%02d01", $year, $month );
 822                 if ( $ymd > 20320101 ) {
 823                         $ymd = 20320101;
 824                 }
 825                 $this->mOffset = $this->mDb->timestamp( "${ymd}000000" );
 826         }
 827 }
 828
 829 /**
 830  * Table-based display with a user-selectable sort order
 831  * @ingroup Pager
 832  */
 833 abstract class TablePager extends IndexPager {
 834         var $mSort;
 835         var $mCurrentRow;
 836
 837         function __construct( IContextSource $context = null ) {
 838                 if ( $context ) {
 839                         $this->setContext( $context );
 840                 }
 841
 842                 $this->mSort = $this->getRequest()->getText( 'sort' );
 843                 if ( !array_key_exists( $this->mSort, $this->getFieldNames() ) ) {
 844                         $this->mSort = $this->getDefaultSort();
 845                 }
 846                 if ( $this->getRequest()->getBool( 'asc' ) ) {
 847                         $this->mDefaultDirection = false;
 848                 } elseif ( $this->getRequest()->getBool( 'desc' ) ) {
 849                         $this->mDefaultDirection = true;
 850                 } /* Else leave it at whatever the class default is */
 851
 852                 parent::__construct();
 853         }
 854
 855         function getStartBody() {
 856                 global $wgStylePath;
 857                 $tableClass = htmlspecialchars( $this->getTableClass() );
 858                 $sortClass = htmlspecialchars( $this->getSortHeaderClass() );
 859
 860                 $s = "<table style='border:1;' class=\"mw-datatable $tableClass\"><thead><tr>\n";
 861                 $fields = $this->getFieldNames();
 862
 863                 # Make table header
 864                 foreach ( $fields as $field => $name ) {
 865                         if ( strval( $name ) == '' ) {
 866                                 $s .= "<th>&#160;</th>\n";
 867                         } elseif ( $this->isFieldSortable( $field ) ) {
 868                                 $query = array( 'sort' => $field, 'limit' => $this->mLimit );
 869                                 if ( $field == $this->mSort ) {
 870                                         # This is the sorted column
 871                                         # Prepare a link that goes in the other sort order
 872                                         if ( $this->mDefaultDirection ) {
 873                                                 # Descending
 874                                                 $image = 'Arr_d.png';
 875                                                 $query['asc'] = '1';
 876                                                 $query['desc'] = '';
 877                                                 $alt = htmlspecialchars( wfMsg( 'descending_abbrev' ) );
 878                                         } else {
 879                                                 # Ascending
 880                                                 $image = 'Arr_u.png';
 881                                                 $query['asc'] = '';
 882                                                 $query['desc'] = '1';
 883                                                 $alt = htmlspecialchars( wfMsg( 'ascending_abbrev' ) );
 884                                         }
 885                                         $image = htmlspecialchars( "$wgStylePath/common/images/$image" );
 886                                         $link = $this->makeLink(
 887                                                 "<img width=\"12\" height=\"12\" alt=\"$alt\" src=\"$image\" />" .
 888                                                 htmlspecialchars( $name ), $query );
 889                                         $s .= "<th class=\"$sortClass\">$link</th>\n";
 890                                 } else {
 891                                         $s .= '<th>' . $this->makeLink( htmlspecialchars( $name ), $query ) . "</th>\n";
 892                                 }
 893                         } else {
 894                                 $s .= '<th>' . htmlspecialchars( $name ) . "</th>\n";
 895                         }
 896                 }
 897                 $s .= "</tr></thead><tbody>\n";
 898                 return $s;
 899         }
 900
 901         function getEndBody() {
 902                 return "</tbody></table>\n";
 903         }
 904
 905         function getEmptyBody() {
 906                 $colspan = count( $this->getFieldNames() );
 907                 $msgEmpty = wfMsgHtml( 'table_pager_empty' );
 908                 return "<tr><td colspan=\"$colspan\">$msgEmpty</td></tr>\n";
 909         }
 910
 911         /**
 912          * @param $row Array
 913          * @return String HTML
 914          */
 915         function formatRow( $row ) {
 916                 $this->mCurrentRow = $row;      # In case formatValue etc need to know
 917                 $s = Xml::openElement( 'tr', $this->getRowAttrs( $row ) );
 918                 $fieldNames = $this->getFieldNames();
 919                 foreach ( $fieldNames as $field => $name ) {
 920                         $value = isset( $row->$field ) ? $row->$field : null;
 921                         $formatted = strval( $this->formatValue( $field, $value ) );
 922                         if ( $formatted == '' ) {
 923                                 $formatted = '&#160;';
 924                         }
 925                         $s .= Xml::tags( 'td', $this->getCellAttrs( $field, $value ), $formatted );
 926                 }
 927                 $s .= "</tr>\n";
 928                 return $s;
 929         }
 930
 931         /**
 932          * Get a class name to be applied to the given row.
 933          *
 934          * @param $row Object: the database result row
 935          * @return String
 936          */
 937         function getRowClass( $row ) {
 938                 return '';
 939         }
 940
 941         /**
 942          * Get attributes to be applied to the given row.
 943          *
 944          * @param $row Object: the database result row
 945          * @return Array of <attr> => <value>
 946          */
 947         function getRowAttrs( $row ) {
 948                 $class = $this->getRowClass( $row );
 949                 if ( $class === '' ) {
 950                         // Return an empty array to avoid clutter in HTML like class=""
 951                         return array();
 952                 } else {
 953                         return array( 'class' => $this->getRowClass( $row ) );
 954                 }
 955         }
 956
 957         /**
 958          * Get any extra attributes to be applied to the given cell. Don't
 959          * take this as an excuse to hardcode styles; use classes and
 960          * CSS instead.  Row context is available in $this->mCurrentRow
 961          *
 962          * @param $field String The column
 963          * @param $value String The cell contents
 964          * @return Array of attr => value
 965          */
 966         function getCellAttrs( $field, $value ) {
 967                 return array( 'class' => 'TablePager_col_' . $field );
 968         }
 969
 970         function getIndexField() {
 971                 return $this->mSort;
 972         }
 973
 974         function getTableClass() {
 975                 return 'TablePager';
 976         }
 977
 978         function getNavClass() {
 979                 return 'TablePager_nav';
 980         }
 981
 982         function getSortHeaderClass() {
 983                 return 'TablePager_sort';
 984         }
 985
 986         /**
 987          * A navigation bar with images
 988          * @return String HTML
 989          */
 990         function getNavigationBar() {
 991                 global $wgStylePath;
 992
 993                 if ( !$this->isNavigationBarShown() ) {
 994                         return '';
 995                 }
 996
 997                 $path = "$wgStylePath/common/images";
 998                 $labels = array(
 999                         'first' => 'table_pager_first',
1000                         'prev' => 'table_pager_prev',
1001                         'next' => 'table_pager_next',
1002                         'last' => 'table_pager_last',
1003                 );
1004                 $images = array(
1005                         'first' => 'arrow_first_25.png',
1006                         'prev' => 'arrow_left_25.png',
1007                         'next' => 'arrow_right_25.png',
1008                         'last' => 'arrow_last_25.png',
1009                 );
1010                 $disabledImages = array(
1011                         'first' => 'arrow_disabled_first_25.png',
1012                         'prev' => 'arrow_disabled_left_25.png',
1013                         'next' => 'arrow_disabled_right_25.png',
1014                         'last' => 'arrow_disabled_last_25.png',
1015                 );
1016                 if( $this->getLang()->isRTL() ) {
1017                         $keys = array_keys( $labels );
1018                         $images = array_combine( $keys, array_reverse( $images ) );
1019                         $disabledImages = array_combine( $keys, array_reverse( $disabledImages ) );
1020                 }
1021
1022                 $linkTexts = array();
1023                 $disabledTexts = array();
1024                 foreach ( $labels as $type => $label ) {
1025                         $msgLabel = wfMsgHtml( $label );
1026                         $linkTexts[$type] = "<img src=\"$path/{$images[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
1027                         $disabledTexts[$type] = "<img src=\"$path/{$disabledImages[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
1028                 }
1029                 $links = $this->getPagingLinks( $linkTexts, $disabledTexts );
1030
1031                 $navClass = htmlspecialchars( $this->getNavClass() );
1032                 $s = "<table class=\"$navClass\"><tr>\n";
1033                 $width = 100 / count( $links ) . '%';
1034                 foreach ( $labels as $type => $label ) {
1035                         $s .= "<td style='width:$width;'>{$links[$type]}</td>\n";
1036                 }
1037                 $s .= "</tr></table>\n";
1038                 return $s;
1039         }
1040
1041         /**
1042          * Get a <select> element which has options for each of the allowed limits
1043          *
1044          * @return String: HTML fragment
1045          */
1046         function getLimitSelect() {
1047                 # Add the current limit from the query string
1048                 # to avoid that the limit is lost after clicking Go next time
1049                 if ( !in_array( $this->mLimit, $this->mLimitsShown ) ) {
1050                         $this->mLimitsShown[] = $this->mLimit;
1051                         sort( $this->mLimitsShown );
1052                 }
1053                 $s = Html::openElement( 'select', array( 'name' => 'limit' ) ) . "\n";
1054                 foreach ( $this->mLimitsShown as $key => $value ) {
1055                         # The pair is either $index => $limit, in which case the $value
1056                         # will be numeric, or $limit => $text, in which case the $value
1057                         # will be a string.
1058                         if( is_int( $value ) ){
1059                                 $limit = $value;
1060                                 $text = $this->getLang()->formatNum( $limit );
1061                         } else {
1062                                 $limit = $key;
1063                                 $text = $value;
1064                         }
1065                         $s .= Xml::option( $text, $limit, $limit == $this->mLimit ) . "\n";
1066                 }
1067                 $s .= Html::closeElement( 'select' );
1068                 return $s;
1069         }
1070
1071         /**
1072          * Get <input type="hidden"> elements for use in a method="get" form.
1073          * Resubmits all defined elements of the query string, except for a
1074          * blacklist, passed in the $blacklist parameter.
1075          *
1076          * @param $blacklist Array parameters from the request query which should not be resubmitted
1077          * @return String: HTML fragment
1078          */
1079         function getHiddenFields( $blacklist = array() ) {
1080                 $blacklist = (array)$blacklist;
1081                 $query = $this->getRequest()->getQueryValues();
1082                 foreach ( $blacklist as $name ) {
1083                         unset( $query[$name] );
1084                 }
1085                 $s = '';
1086                 foreach ( $query as $name => $value ) {
1087                         $encName = htmlspecialchars( $name );
1088                         $encValue = htmlspecialchars( $value );
1089                         $s .= "<input type=\"hidden\" name=\"$encName\" value=\"$encValue\"/>\n";
1090                 }
1091                 return $s;
1092         }
1093
1094         /**
1095          * Get a form containing a limit selection dropdown
1096          *
1097          * @return String: HTML fragment
1098          */
1099         function getLimitForm() {
1100                 global $wgScript;
1101
1102                 return Xml::openElement(
1103                         'form',
1104                         array(
1105                                 'method' => 'get',
1106                                 'action' => $wgScript
1107                         ) ) . "\n" . $this->getLimitDropdown() . "</form>\n";
1108         }
1109
1110         /**
1111          * Gets a limit selection dropdown
1112          *
1113          * @return string
1114          */
1115         function getLimitDropdown() {
1116                 # Make the select with some explanatory text
1117                 $msgSubmit = wfMsgHtml( 'table_pager_limit_submit' );
1118
1119                 return wfMsgHtml( 'table_pager_limit', $this->getLimitSelect() ) .
1120                         "\n<input type=\"submit\" value=\"$msgSubmit\"/>\n" .
1121                         $this->getHiddenFields( array( 'limit' ) );
1122         }
1123
1124         /**
1125          * Return true if the named field should be sortable by the UI, false
1126          * otherwise
1127          *
1128          * @param $field String
1129          */
1130         abstract function isFieldSortable( $field );
1131
1132         /**
1133          * Format a table cell. The return value should be HTML, but use an empty
1134          * string not &#160; for empty cells. Do not include the <td> and </td>.
1135          *
1136          * The current result row is available as $this->mCurrentRow, in case you
1137          * need more context.
1138          *
1139          * @param $name String: the database field name
1140          * @param $value String: the value retrieved from the database
1141          */
1142         abstract function formatValue( $name, $value );
1143
1144         /**
1145          * The database field name used as a default sort order
1146          */
1147         abstract function getDefaultSort();
1148
1149         /**
1150          * An array mapping database field names to a textual description of the
1151          * field name, for use in the table header. The description should be plain
1152          * text, it will be HTML-escaped later.
1153          *
1154          * @return Array
1155          */
1156         abstract function getFieldNames();
1157 }