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
 333                 if ( $this->mResult->numRows() ) {
 334                         # Do any special query batches before display
 335                         $this->doBatchLookups();
 336                 }
 337
 338                 # Don't use any extra rows returned by the query
 339                 $numRows = min( $this->mResult->numRows(), $this->mLimit );
 340
 341                 $s = $this->getStartBody();
 342                 if ( $numRows ) {
 343                         if ( $this->mIsBackwards ) {
 344                                 for ( $i = $numRows - 1; $i >= 0; $i-- ) {
 345                                         $this->mResult->seek( $i );
 346                                         $row = $this->mResult->fetchObject();
 347                                         $s .= $this->formatRow( $row );
 348                                 }
 349                         } else {
 350                                 $this->mResult->seek( 0 );
 351                                 for ( $i = 0; $i < $numRows; $i++ ) {
 352                                         $row = $this->mResult->fetchObject();
 353                                         $s .= $this->formatRow( $row );
 354                                 }
 355                         }
 356                 } else {
 357                         $s .= $this->getEmptyBody();
 358                 }
 359                 $s .= $this->getEndBody();
 360                 return $s;
 361         }
 362
 363         /**
 364          * Make a self-link
 365          *
 366          * @param $text String: text displayed on the link
 367          * @param $query Array: associative array of paramter to be in the query string
 368          * @param $type String: value of the "rel" attribute
 369          * @return String: HTML fragment
 370          */
 371         function makeLink($text, $query = null, $type=null) {
 372                 if ( $query === null ) {
 373                         return $text;
 374                 }
 375
 376                 $attrs = array();
 377                 if( in_array( $type, array( 'first', 'prev', 'next', 'last' ) ) ) {
 378                         # HTML5 rel attributes
 379                         $attrs['rel'] = $type;
 380                 }
 381
 382                 if( $type ) {
 383                         $attrs['class'] = "mw-{$type}link";
 384                 }
 385                 return Linker::linkKnown(
 386                         $this->getTitle(),
 387                         $text,
 388                         $attrs,
 389                         $query + $this->getDefaultQuery()
 390                 );
 391         }
 392
 393         /**
 394          * Called from getBody(), before getStartBody() is called and
 395          * after doQuery() was called. This will be called only if there
 396          * are rows in the result set.
 397          */
 398         protected function doBatchLookups() {}
 399
 400         /**
 401          * Hook into getBody(), allows text to be inserted at the start. This
 402          * will be called even if there are no rows in the result set.
 403          *
 404          * @return String
 405          */
 406         protected function getStartBody() {
 407                 return '';
 408         }
 409
 410         /**
 411          * Hook into getBody() for the end of the list
 412          *
 413          * @return String
 414          */
 415         protected function getEndBody() {
 416                 return '';
 417         }
 418
 419         /**
 420          * Hook into getBody(), for the bit between the start and the
 421          * end when there are no rows
 422          *
 423          * @return String
 424          */
 425         protected function getEmptyBody() {
 426                 return '';
 427         }
 428
 429         /**
 430          * Get an array of query parameters that should be put into self-links.
 431          * By default, all parameters passed in the URL are used, except for a
 432          * short blacklist.
 433          *
 434          * @return Associative array
 435          */
 436         function getDefaultQuery() {
 437                 if ( !isset( $this->mDefaultQuery ) ) {
 438                         $this->mDefaultQuery = $this->getRequest()->getQueryValues();
 439                         unset( $this->mDefaultQuery['title'] );
 440                         unset( $this->mDefaultQuery['dir'] );
 441                         unset( $this->mDefaultQuery['offset'] );
 442                         unset( $this->mDefaultQuery['limit'] );
 443                         unset( $this->mDefaultQuery['order'] );
 444                         unset( $this->mDefaultQuery['month'] );
 445                         unset( $this->mDefaultQuery['year'] );
 446                 }
 447                 return $this->mDefaultQuery;
 448         }
 449
 450         /**
 451          * Get the number of rows in the result set
 452          *
 453          * @return Integer
 454          */
 455         function getNumRows() {
 456                 if ( !$this->mQueryDone ) {
 457                         $this->doQuery();
 458                 }
 459                 return $this->mResult->numRows();
 460         }
 461
 462         /**
 463          * Get a URL query array for the prev, next, first and last links.
 464          *
 465          * @return Array
 466          */
 467         function getPagingQueries() {
 468                 if ( !$this->mQueryDone ) {
 469                         $this->doQuery();
 470                 }
 471
 472                 # Don't announce the limit everywhere if it's the default
 473                 $urlLimit = $this->mLimit == $this->mDefaultLimit ? '' : $this->mLimit;
 474
 475                 if ( $this->mIsFirst ) {
 476                         $prev = false;
 477                         $first = false;
 478                 } else {
 479                         $prev = array(
 480                                 'dir' => 'prev',
 481                                 'offset' => $this->mFirstShown,
 482                                 'limit' => $urlLimit
 483                         );
 484                         $first = array( 'limit' => $urlLimit );
 485                 }
 486                 if ( $this->mIsLast ) {
 487                         $next = false;
 488                         $last = false;
 489                 } else {
 490                         $next = array( 'offset' => $this->mLastShown, 'limit' => $urlLimit );
 491                         $last = array( 'dir' => 'prev', 'limit' => $urlLimit );
 492                 }
 493                 return array(
 494                         'prev' => $prev,
 495                         'next' => $next,
 496                         'first' => $first,
 497                         'last' => $last
 498                 );
 499         }
 500
 501         /**
 502          * Returns whether to show the "navigation bar"
 503          *
 504          * @return Boolean
 505          */
 506         function isNavigationBarShown() {
 507                 if ( !$this->mQueryDone ) {
 508                         $this->doQuery();
 509                 }
 510                 // Hide navigation by default if there is nothing to page
 511                 return !($this->mIsFirst && $this->mIsLast);
 512         }
 513
 514         /**
 515          * Get paging links. If a link is disabled, the item from $disabledTexts
 516          * will be used. If there is no such item, the unlinked text from
 517          * $linkTexts will be used. Both $linkTexts and $disabledTexts are arrays
 518          * of HTML.
 519          *
 520          * @param $linkTexts Array
 521          * @param $disabledTexts Array
 522          * @return Array
 523          */
 524         function getPagingLinks( $linkTexts, $disabledTexts = array() ) {
 525                 $queries = $this->getPagingQueries();
 526                 $links = array();
 527                 foreach ( $queries as $type => $query ) {
 528                         if ( $query !== false ) {
 529                                 $links[$type] = $this->makeLink(
 530                                         $linkTexts[$type],
 531                                         $queries[$type],
 532                                         $type
 533                                 );
 534                         } elseif ( isset( $disabledTexts[$type] ) ) {
 535                                 $links[$type] = $disabledTexts[$type];
 536                         } else {
 537                                 $links[$type] = $linkTexts[$type];
 538                         }
 539                 }
 540                 return $links;
 541         }
 542
 543         function getLimitLinks() {
 544                 $links = array();
 545                 if ( $this->mIsBackwards ) {
 546                         $offset = $this->mPastTheEndIndex;
 547                 } else {
 548                         $offset = $this->mOffset;
 549                 }
 550                 foreach ( $this->mLimitsShown as $limit ) {
 551                         $links[] = $this->makeLink(
 552                                 $this->getLanguage()->formatNum( $limit ),
 553                                 array( 'offset' => $offset, 'limit' => $limit ),
 554                                 'num'
 555                         );
 556                 }
 557                 return $links;
 558         }
 559
 560         /**
 561          * Abstract formatting function. This should return an HTML string
 562          * representing the result row $row. Rows will be concatenated and
 563          * returned by getBody()
 564          *
 565          * @param $row Object: database row
 566          * @return String
 567          */
 568         abstract function formatRow( $row );
 569
 570         /**
 571          * This function should be overridden to provide all parameters
 572          * needed for the main paged query. It returns an associative
 573          * array with the following elements:
 574          *    tables => Table(s) for passing to Database::select()
 575          *    fields => Field(s) for passing to Database::select(), may be *
 576          *    conds => WHERE conditions
 577          *    options => option array
 578          *    join_conds => JOIN conditions
 579          *
 580          * @return Array
 581          */
 582         abstract function getQueryInfo();
 583
 584         /**
 585          * This function should be overridden to return the name of the index fi-
 586          * eld.  If the pager supports multiple orders, it may return an array of
 587          * 'querykey' => 'indexfield' pairs, so that a request with &count=querykey
 588          * will use indexfield to sort.  In this case, the first returned key is
 589          * the default.
 590          *
 591          * Needless to say, it's really not a good idea to use a non-unique index
 592          * for this!  That won't page right.
 593          *
 594          * @return string|Array
 595          */
 596         abstract function getIndexField();
 597
 598         /**
 599          * This function should be overridden to return the names of secondary columns
 600          * to order by in addition to the column in getIndexField(). These fields will
 601          * not be used in the pager offset or in any links for users.
 602          *
 603          * If getIndexField() returns an array of 'querykey' => 'indexfield' pairs then
 604          * this must return a corresponding array of 'querykey' => array( fields...) pairs
 605          * in order for a request with &count=querykey to use array( fields...) to sort.
 606          *
 607          * This is useful for pagers that GROUP BY a unique column (say page_id)
 608          * and ORDER BY another (say page_len). Using GROUP BY and ORDER BY both on
 609          * page_len,page_id avoids temp tables (given a page_len index). This would
 610          * also work if page_id was non-unique but we had a page_len,page_id index.
 611          *
 612          * @return Array
 613          */
 614         protected function getExtraSortFields() { return array(); }
 615
 616         /**
 617          * Return the default sorting direction: false for ascending, true for de-
 618          * scending.  You can also have an associative array of ordertype => dir,
 619          * if multiple order types are supported.  In this case getIndexField()
 620          * must return an array, and the keys of that must exactly match the keys
 621          * of this.
 622          *
 623          * For backward compatibility, this method's return value will be ignored
 624          * if $this->mDefaultDirection is already set when the constructor is
 625          * called, for instance if it's statically initialized.  In that case the
 626          * value of that variable (which must be a boolean) will be used.
 627          *
 628          * Note that despite its name, this does not return the value of the
 629          * $this->mDefaultDirection member variable.  That's the default for this
 630          * particular instantiation, which is a single value.  This is the set of
 631          * all defaults for the class.
 632          *
 633          * @return Boolean
 634          */
 635         protected function getDefaultDirections() { return false; }
 636 }
 637
 638
 639 /**
 640  * IndexPager with an alphabetic list and a formatted navigation bar
 641  * @ingroup Pager
 642  */
 643 abstract class AlphabeticPager extends IndexPager {
 644
 645         /**
 646          * Shamelessly stolen bits from ReverseChronologicalPager,
 647          * didn't want to do class magic as may be still revamped
 648          *
 649          * @return String HTML
 650          */
 651         function getNavigationBar() {
 652                 if ( !$this->isNavigationBarShown() ) return '';
 653
 654                 if( isset( $this->mNavigationBar ) ) {
 655                         return $this->mNavigationBar;
 656                 }
 657
 658                 $lang = $this->getLanguage();
 659
 660                 $opts = array( 'parsemag', 'escapenoentities' );
 661                 $linkTexts = array(
 662                         'prev' => wfMsgExt(
 663                                 'prevn',
 664                                 $opts,
 665                                 $lang->formatNum( $this->mLimit )
 666                         ),
 667                         'next' => wfMsgExt(
 668                                 'nextn',
 669                                 $opts,
 670                                 $lang->formatNum($this->mLimit )
 671                         ),
 672                         'first' => wfMsgExt( 'page_first', $opts ),
 673                         'last' => wfMsgExt( 'page_last', $opts )
 674                 );
 675
 676                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 677                 $limitLinks = $this->getLimitLinks();
 678                 $limits = $lang->pipeList( $limitLinks );
 679
 680                 $this->mNavigationBar =
 681                         "(" . $lang->pipeList(
 682                                 array( $pagingLinks['first'],
 683                                 $pagingLinks['last'] )
 684                         ) . ") " .
 685                         wfMsgHtml( 'viewprevnext', $pagingLinks['prev'],
 686                         $pagingLinks['next'], $limits );
 687
 688                 if( !is_array( $this->getIndexField() ) ) {
 689                         # Early return to avoid undue nesting
 690                         return $this->mNavigationBar;
 691                 }
 692
 693                 $extra = '';
 694                 $first = true;
 695                 $msgs = $this->getOrderTypeMessages();
 696                 foreach( array_keys( $msgs ) as $order ) {
 697                         if( $first ) {
 698                                 $first = false;
 699                         } else {
 700                                 $extra .= wfMsgExt( 'pipe-separator' , 'escapenoentities' );
 701                         }
 702
 703                         if( $order == $this->mOrderType ) {
 704                                 $extra .= wfMsgHTML( $msgs[$order] );
 705                         } else {
 706                                 $extra .= $this->makeLink(
 707                                         wfMsgHTML( $msgs[$order] ),
 708                                         array( 'order' => $order )
 709                                 );
 710                         }
 711                 }
 712
 713                 if( $extra !== '' ) {
 714                         $this->mNavigationBar .= " ($extra)";
 715                 }
 716
 717                 return $this->mNavigationBar;
 718         }
 719
 720         /**
 721          * If this supports multiple order type messages, give the message key for
 722          * enabling each one in getNavigationBar.  The return type is an associa-
 723          * tive array whose keys must exactly match the keys of the array returned
 724          * by getIndexField(), and whose values are message keys.
 725          *
 726          * @return Array
 727          */
 728         protected function getOrderTypeMessages() {
 729                 return null;
 730         }
 731 }
 732
 733 /**
 734  * IndexPager with a formatted navigation bar
 735  * @ingroup Pager
 736  */
 737 abstract class ReverseChronologicalPager extends IndexPager {
 738         public $mDefaultDirection = true;
 739         public $mYear;
 740         public $mMonth;
 741
 742         function getNavigationBar() {
 743                 if ( !$this->isNavigationBarShown() ) {
 744                         return '';
 745                 }
 746
 747                 if ( isset( $this->mNavigationBar ) ) {
 748                         return $this->mNavigationBar;
 749                 }
 750
 751                 $nicenumber = $this->getLanguage()->formatNum( $this->mLimit );
 752                 $linkTexts = array(
 753                         'prev' => wfMsgExt(
 754                                 'pager-newer-n',
 755                                 array( 'parsemag', 'escape' ),
 756                                 $nicenumber
 757                         ),
 758                         'next' => wfMsgExt(
 759                                 'pager-older-n',
 760                                 array( 'parsemag', 'escape' ),
 761                                 $nicenumber
 762                         ),
 763                         'first' => wfMsgHtml( 'histlast' ),
 764                         'last' => wfMsgHtml( 'histfirst' )
 765                 );
 766
 767                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 768                 $limitLinks = $this->getLimitLinks();
 769                 $limits = $this->getLanguage()->pipeList( $limitLinks );
 770
 771                 $this->mNavigationBar = "({$pagingLinks['first']}" .
 772                         wfMsgExt( 'pipe-separator' , 'escapenoentities' ) .
 773                         "{$pagingLinks['last']}) " .
 774                         wfMsgHTML(
 775                                 'viewprevnext',
 776                                 $pagingLinks['prev'], $pagingLinks['next'],
 777                                 $limits
 778                         );
 779                 return $this->mNavigationBar;
 780         }
 781
 782         function getDateCond( $year, $month ) {
 783                 $year = intval($year);
 784                 $month = intval($month);
 785                 // Basic validity checks
 786                 $this->mYear = $year > 0 ? $year : false;
 787                 $this->mMonth = ($month > 0 && $month < 13) ? $month : false;
 788                 // Given an optional year and month, we need to generate a timestamp
 789                 // to use as "WHERE rev_timestamp <= result"
 790                 // Examples: year = 2006 equals < 20070101 (+000000)
 791                 // year=2005, month=1    equals < 20050201
 792                 // year=2005, month=12   equals < 20060101
 793                 if ( !$this->mYear && !$this->mMonth ) {
 794                         return;
 795                 }
 796                 if ( $this->mYear ) {
 797                         $year = $this->mYear;
 798                 } else {
 799                         // If no year given, assume the current one
 800                         $year = gmdate( 'Y' );
 801                         // If this month hasn't happened yet this year, go back to last year's month
 802                         if( $this->mMonth > gmdate( 'n' ) ) {
 803                                 $year--;
 804                         }
 805                 }
 806                 if ( $this->mMonth ) {
 807                         $month = $this->mMonth + 1;
 808                         // For December, we want January 1 of the next year
 809                         if ($month > 12) {
 810                                 $month = 1;
 811                                 $year++;
 812                         }
 813                 } else {
 814                         // No month implies we want up to the end of the year in question
 815                         $month = 1;
 816                         $year++;
 817                 }
 818                 // Y2K38 bug
 819                 if ( $year > 2032 ) {
 820                         $year = 2032;
 821                 }
 822                 $ymd = (int)sprintf( "%04d%02d01", $year, $month );
 823                 if ( $ymd > 20320101 ) {
 824                         $ymd = 20320101;
 825                 }
 826                 $this->mOffset = $this->mDb->timestamp( "${ymd}000000" );
 827         }
 828 }
 829
 830 /**
 831  * Table-based display with a user-selectable sort order
 832  * @ingroup Pager
 833  */
 834 abstract class TablePager extends IndexPager {
 835         var $mSort;
 836         var $mCurrentRow;
 837
 838         function __construct( IContextSource $context = null ) {
 839                 if ( $context ) {
 840                         $this->setContext( $context );
 841                 }
 842
 843                 $this->mSort = $this->getRequest()->getText( 'sort' );
 844                 if ( !array_key_exists( $this->mSort, $this->getFieldNames() ) ) {
 845                         $this->mSort = $this->getDefaultSort();
 846                 }
 847                 if ( $this->getRequest()->getBool( 'asc' ) ) {
 848                         $this->mDefaultDirection = false;
 849                 } elseif ( $this->getRequest()->getBool( 'desc' ) ) {
 850                         $this->mDefaultDirection = true;
 851                 } /* Else leave it at whatever the class default is */
 852
 853                 parent::__construct();
 854         }
 855
 856         function getStartBody() {
 857                 global $wgStylePath;
 858                 $tableClass = htmlspecialchars( $this->getTableClass() );
 859                 $sortClass = htmlspecialchars( $this->getSortHeaderClass() );
 860
 861                 $s = "<table style='border:1;' class=\"mw-datatable $tableClass\"><thead><tr>\n";
 862                 $fields = $this->getFieldNames();
 863
 864                 # Make table header
 865                 foreach ( $fields as $field => $name ) {
 866                         if ( strval( $name ) == '' ) {
 867                                 $s .= "<th>&#160;</th>\n";
 868                         } elseif ( $this->isFieldSortable( $field ) ) {
 869                                 $query = array( 'sort' => $field, 'limit' => $this->mLimit );
 870                                 if ( $field == $this->mSort ) {
 871                                         # This is the sorted column
 872                                         # Prepare a link that goes in the other sort order
 873                                         if ( $this->mDefaultDirection ) {
 874                                                 # Descending
 875                                                 $image = 'Arr_d.png';
 876                                                 $query['asc'] = '1';
 877                                                 $query['desc'] = '';
 878                                                 $alt = htmlspecialchars( wfMsg( 'descending_abbrev' ) );
 879                                         } else {
 880                                                 # Ascending
 881                                                 $image = 'Arr_u.png';
 882                                                 $query['asc'] = '';
 883                                                 $query['desc'] = '1';
 884                                                 $alt = htmlspecialchars( wfMsg( 'ascending_abbrev' ) );
 885                                         }
 886                                         $image = htmlspecialchars( "$wgStylePath/common/images/$image" );
 887                                         $link = $this->makeLink(
 888                                                 "<img width=\"12\" height=\"12\" alt=\"$alt\" src=\"$image\" />" .
 889                                                 htmlspecialchars( $name ), $query );
 890                                         $s .= "<th class=\"$sortClass\">$link</th>\n";
 891                                 } else {
 892                                         $s .= '<th>' . $this->makeLink( htmlspecialchars( $name ), $query ) . "</th>\n";
 893                                 }
 894                         } else {
 895                                 $s .= '<th>' . htmlspecialchars( $name ) . "</th>\n";
 896                         }
 897                 }
 898                 $s .= "</tr></thead><tbody>\n";
 899                 return $s;
 900         }
 901
 902         function getEndBody() {
 903                 return "</tbody></table>\n";
 904         }
 905
 906         function getEmptyBody() {
 907                 $colspan = count( $this->getFieldNames() );
 908                 $msgEmpty = wfMsgHtml( 'table_pager_empty' );
 909                 return "<tr><td colspan=\"$colspan\">$msgEmpty</td></tr>\n";
 910         }
 911
 912         /**
 913          * @param $row Array
 914          * @return String HTML
 915          */
 916         function formatRow( $row ) {
 917                 $this->mCurrentRow = $row;      # In case formatValue etc need to know
 918                 $s = Xml::openElement( 'tr', $this->getRowAttrs( $row ) );
 919                 $fieldNames = $this->getFieldNames();
 920                 foreach ( $fieldNames as $field => $name ) {
 921                         $value = isset( $row->$field ) ? $row->$field : null;
 922                         $formatted = strval( $this->formatValue( $field, $value ) );
 923                         if ( $formatted == '' ) {
 924                                 $formatted = '&#160;';
 925                         }
 926                         $s .= Xml::tags( 'td', $this->getCellAttrs( $field, $value ), $formatted );
 927                 }
 928                 $s .= "</tr>\n";
 929                 return $s;
 930         }
 931
 932         /**
 933          * Get a class name to be applied to the given row.
 934          *
 935          * @param $row Object: the database result row
 936          * @return String
 937          */
 938         function getRowClass( $row ) {
 939                 return '';
 940         }
 941
 942         /**
 943          * Get attributes to be applied to the given row.
 944          *
 945          * @param $row Object: the database result row
 946          * @return Array of <attr> => <value>
 947          */
 948         function getRowAttrs( $row ) {
 949                 $class = $this->getRowClass( $row );
 950                 if ( $class === '' ) {
 951                         // Return an empty array to avoid clutter in HTML like class=""
 952                         return array();
 953                 } else {
 954                         return array( 'class' => $this->getRowClass( $row ) );
 955                 }
 956         }
 957
 958         /**
 959          * Get any extra attributes to be applied to the given cell. Don't
 960          * take this as an excuse to hardcode styles; use classes and
 961          * CSS instead.  Row context is available in $this->mCurrentRow
 962          *
 963          * @param $field String The column
 964          * @param $value String The cell contents
 965          * @return Array of attr => value
 966          */
 967         function getCellAttrs( $field, $value ) {
 968                 return array( 'class' => 'TablePager_col_' . $field );
 969         }
 970
 971         function getIndexField() {
 972                 return $this->mSort;
 973         }
 974
 975         function getTableClass() {
 976                 return 'TablePager';
 977         }
 978
 979         function getNavClass() {
 980                 return 'TablePager_nav';
 981         }
 982
 983         function getSortHeaderClass() {
 984                 return 'TablePager_sort';
 985         }
 986
 987         /**
 988          * A navigation bar with images
 989          * @return String HTML
 990          */
 991         function getNavigationBar() {
 992                 global $wgStylePath;
 993
 994                 if ( !$this->isNavigationBarShown() ) {
 995                         return '';
 996                 }
 997
 998                 $path = "$wgStylePath/common/images";
 999                 $labels = array(
1000                         'first' => 'table_pager_first',
1001                         'prev' => 'table_pager_prev',
1002                         'next' => 'table_pager_next',
1003                         'last' => 'table_pager_last',
1004                 );
1005                 $images = array(
1006                         'first' => 'arrow_first_25.png',
1007                         'prev' => 'arrow_left_25.png',
1008                         'next' => 'arrow_right_25.png',
1009                         'last' => 'arrow_last_25.png',
1010                 );
1011                 $disabledImages = array(
1012                         'first' => 'arrow_disabled_first_25.png',
1013                         'prev' => 'arrow_disabled_left_25.png',
1014                         'next' => 'arrow_disabled_right_25.png',
1015                         'last' => 'arrow_disabled_last_25.png',
1016                 );
1017                 if( $this->getLanguage()->isRTL() ) {
1018                         $keys = array_keys( $labels );
1019                         $images = array_combine( $keys, array_reverse( $images ) );
1020                         $disabledImages = array_combine( $keys, array_reverse( $disabledImages ) );
1021                 }
1022
1023                 $linkTexts = array();
1024                 $disabledTexts = array();
1025                 foreach ( $labels as $type => $label ) {
1026                         $msgLabel = wfMsgHtml( $label );
1027                         $linkTexts[$type] = "<img src=\"$path/{$images[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
1028                         $disabledTexts[$type] = "<img src=\"$path/{$disabledImages[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
1029                 }
1030                 $links = $this->getPagingLinks( $linkTexts, $disabledTexts );
1031
1032                 $navClass = htmlspecialchars( $this->getNavClass() );
1033                 $s = "<table class=\"$navClass\"><tr>\n";
1034                 $width = 100 / count( $links ) . '%';
1035                 foreach ( $labels as $type => $label ) {
1036                         $s .= "<td style='width:$width;'>{$links[$type]}</td>\n";
1037                 }
1038                 $s .= "</tr></table>\n";
1039                 return $s;
1040         }
1041
1042         /**
1043          * Get a <select> element which has options for each of the allowed limits
1044          *
1045          * @return String: HTML fragment
1046          */
1047         function getLimitSelect() {
1048                 # Add the current limit from the query string
1049                 # to avoid that the limit is lost after clicking Go next time
1050                 if ( !in_array( $this->mLimit, $this->mLimitsShown ) ) {
1051                         $this->mLimitsShown[] = $this->mLimit;
1052                         sort( $this->mLimitsShown );
1053                 }
1054                 $s = Html::openElement( 'select', array( 'name' => 'limit' ) ) . "\n";
1055                 foreach ( $this->mLimitsShown as $key => $value ) {
1056                         # The pair is either $index => $limit, in which case the $value
1057                         # will be numeric, or $limit => $text, in which case the $value
1058                         # will be a string.
1059                         if( is_int( $value ) ){
1060                                 $limit = $value;
1061                                 $text = $this->getLanguage()->formatNum( $limit );
1062                         } else {
1063                                 $limit = $key;
1064                                 $text = $value;
1065                         }
1066                         $s .= Xml::option( $text, $limit, $limit == $this->mLimit ) . "\n";
1067                 }
1068                 $s .= Html::closeElement( 'select' );
1069                 return $s;
1070         }
1071
1072         /**
1073          * Get <input type="hidden"> elements for use in a method="get" form.
1074          * Resubmits all defined elements of the query string, except for a
1075          * blacklist, passed in the $blacklist parameter.
1076          *
1077          * @param $blacklist Array parameters from the request query which should not be resubmitted
1078          * @return String: HTML fragment
1079          */
1080         function getHiddenFields( $blacklist = array() ) {
1081                 $blacklist = (array)$blacklist;
1082                 $query = $this->getRequest()->getQueryValues();
1083                 foreach ( $blacklist as $name ) {
1084                         unset( $query[$name] );
1085                 }
1086                 $s = '';
1087                 foreach ( $query as $name => $value ) {
1088                         $encName = htmlspecialchars( $name );
1089                         $encValue = htmlspecialchars( $value );
1090                         $s .= "<input type=\"hidden\" name=\"$encName\" value=\"$encValue\"/>\n";
1091                 }
1092                 return $s;
1093         }
1094
1095         /**
1096          * Get a form containing a limit selection dropdown
1097          *
1098          * @return String: HTML fragment
1099          */
1100         function getLimitForm() {
1101                 global $wgScript;
1102
1103                 return Xml::openElement(
1104                         'form',
1105                         array(
1106                                 'method' => 'get',
1107                                 'action' => $wgScript
1108                         ) ) . "\n" . $this->getLimitDropdown() . "</form>\n";
1109         }
1110
1111         /**
1112          * Gets a limit selection dropdown
1113          *
1114          * @return string
1115          */
1116         function getLimitDropdown() {
1117                 # Make the select with some explanatory text
1118                 $msgSubmit = wfMsgHtml( 'table_pager_limit_submit' );
1119
1120                 return wfMsgHtml( 'table_pager_limit', $this->getLimitSelect() ) .
1121                         "\n<input type=\"submit\" value=\"$msgSubmit\"/>\n" .
1122                         $this->getHiddenFields( array( 'limit' ) );
1123         }
1124
1125         /**
1126          * Return true if the named field should be sortable by the UI, false
1127          * otherwise
1128          *
1129          * @param $field String
1130          */
1131         abstract function isFieldSortable( $field );
1132
1133         /**
1134          * Format a table cell. The return value should be HTML, but use an empty
1135          * string not &#160; for empty cells. Do not include the <td> and </td>.
1136          *
1137          * The current result row is available as $this->mCurrentRow, in case you
1138          * need more context.
1139          *
1140          * @param $name String: the database field name
1141          * @param $value String: the value retrieved from the database
1142          */
1143         abstract function formatValue( $name, $value );
1144
1145         /**
1146          * The database field name used as a default sort order
1147          */
1148         abstract function getDefaultSort();
1149
1150         /**
1151          * An array mapping database field names to a textual description of the
1152          * field name, for use in the table header. The description should be plain
1153          * text, it will be HTML-escaped later.
1154          *
1155          * @return Array
1156          */
1157         abstract function getFieldNames();
1158 }