includes/Pager.php

   1 <?php
   2 /**
   3  * Efficient paging for SQL queries.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Pager
  22  */
  23
  24 /**
  25  * @defgroup Pager Pager
  26  */
  27
  28 /**
  29  * Basic pager interface.
  30  * @ingroup Pager
  31  */
  32 interface Pager {
  33         function getNavigationBar();
  34         function getBody();
  35 }
  36
  37 /**
  38  * IndexPager is an efficient pager which uses a (roughly unique) index in the
  39  * data set to implement paging, rather than a "LIMIT offset,limit" clause.
  40  * In MySQL, such a limit/offset clause requires counting through the
  41  * specified number of offset rows to find the desired data, which can be
  42  * expensive for large offsets.
  43  *
  44  * ReverseChronologicalPager is a child class of the abstract IndexPager, and
  45  * contains  some formatting and display code which is specific to the use of
  46  * timestamps as  indexes. Here is a synopsis of its operation:
  47  *
  48  *    * The query is specified by the offset, limit and direction (dir)
  49  *      parameters, in addition to any subclass-specific parameters.
  50  *    * The offset is the non-inclusive start of the DB query. A row with an
  51  *      index value equal to the offset will never be shown.
  52  *    * The query may either be done backwards, where the rows are returned by
  53  *      the database in the opposite order to which they are displayed to the
  54  *      user, or forwards. This is specified by the "dir" parameter, dir=prev
  55  *      means backwards, anything else means forwards. The offset value
  56  *      specifies the start of the database result set, which may be either
  57  *      the start or end of the displayed data set. This allows "previous"
  58  *      links to be implemented without knowledge of the index value at the
  59  *      start of the previous page.
  60  *    * An additional row beyond the user-specified limit is always requested.
  61  *      This allows us to tell whether we should display a "next" link in the
  62  *      case of forwards mode, or a "previous" link in the case of backwards
  63  *      mode. Determining whether to display the other link (the one for the
  64  *      page before the start of the database result set) can be done
  65  *      heuristically by examining the offset.
  66  *
  67  *    * An empty offset indicates that the offset condition should be omitted
  68  *      from the query. This naturally produces either the first page or the
  69  *      last page depending on the dir parameter.
  70  *
  71  *  Subclassing the pager to implement concrete functionality should be fairly
  72  *  simple, please see the examples in HistoryPage.php and
  73  *  SpecialBlockList.php. You just need to override formatRow(),
  74  *  getQueryInfo() and getIndexField(). Don't forget to call the parent
  75  *  constructor if you override it.
  76  *
  77  * @ingroup Pager
  78  */
  79 abstract class IndexPager extends ContextSource implements Pager {
  80         public $mRequest;
  81         public $mLimitsShown = array( 20, 50, 100, 250, 500 );
  82         public $mDefaultLimit = 50;
  83         public $mOffset, $mLimit;
  84         public $mQueryDone = false;
  85         public $mDb;
  86         public $mPastTheEndRow;
  87
  88         /**
  89          * The index to actually be used for ordering. This is a single column,
  90          * for one ordering, even if multiple orderings are supported.
  91          */
  92         protected $mIndexField;
  93         /**
  94          * An array of secondary columns to order by. These fields are not part of the offset.
  95          * This is a column list for one ordering, even if multiple orderings are supported.
  96          */
  97         protected $mExtraSortFields;
  98         /** For pages that support multiple types of ordering, which one to use.
  99          */
 100         protected $mOrderType;
 101         /**
 102          * $mDefaultDirection gives the direction to use when sorting results:
 103          * false for ascending, true for descending.  If $mIsBackwards is set, we
 104          * start from the opposite end, but we still sort the page itself according
 105          * to $mDefaultDirection.  E.g., if $mDefaultDirection is false but we're
 106          * going backwards, we'll display the last page of results, but the last
 107          * result will be at the bottom, not the top.
 108          *
 109          * Like $mIndexField, $mDefaultDirection will be a single value even if the
 110          * class supports multiple default directions for different order types.
 111          */
 112         public $mDefaultDirection;
 113         public $mIsBackwards;
 114
 115         /** True if the current result set is the first one */
 116         public $mIsFirst;
 117         public $mIsLast;
 118
 119         protected $mLastShown, $mFirstShown, $mPastTheEndIndex, $mDefaultQuery, $mNavigationBar;
 120
 121         /**
 122          * Result object for the query. Warning: seek before use.
 123          *
 124          * @var ResultWrapper
 125          */
 126         public $mResult;
 127
 128         public function __construct( IContextSource $context = null ) {
 129                 if ( $context ) {
 130                         $this->setContext( $context );
 131                 }
 132
 133                 $this->mRequest = $this->getRequest();
 134
 135                 # NB: the offset is quoted, not validated. It is treated as an
 136                 # arbitrary string to support the widest variety of index types. Be
 137                 # careful outputting it into HTML!
 138                 $this->mOffset = $this->mRequest->getText( 'offset' );
 139
 140                 # Use consistent behavior for the limit options
 141                 $this->mDefaultLimit = intval( $this->getUser()->getOption( 'rclimit' ) );
 142                 list( $this->mLimit, /* $offset */ ) = $this->mRequest->getLimitOffset();
 143
 144                 $this->mIsBackwards = ( $this->mRequest->getVal( 'dir' ) == 'prev' );
 145                 $this->mDb = wfGetDB( DB_SLAVE );
 146
 147                 $index = $this->getIndexField(); // column to sort on
 148                 $extraSort = $this->getExtraSortFields(); // extra columns to sort on for query planning
 149                 $order = $this->mRequest->getVal( 'order' );
 150                 if( is_array( $index ) && isset( $index[$order] ) ) {
 151                         $this->mOrderType = $order;
 152                         $this->mIndexField = $index[$order];
 153                         $this->mExtraSortFields = isset( $extraSort[$order] )
 154                                 ? (array)$extraSort[$order]
 155                                 : array();
 156                 } elseif( is_array( $index ) ) {
 157                         # First element is the default
 158                         reset( $index );
 159                         list( $this->mOrderType, $this->mIndexField ) = each( $index );
 160                         $this->mExtraSortFields = isset( $extraSort[$this->mOrderType] )
 161                                 ? (array)$extraSort[$this->mOrderType]
 162                                 : array();
 163                 } else {
 164                         # $index is not an array
 165                         $this->mOrderType = null;
 166                         $this->mIndexField = $index;
 167                         $this->mExtraSortFields = (array)$extraSort;
 168                 }
 169
 170                 if( !isset( $this->mDefaultDirection ) ) {
 171                         $dir = $this->getDefaultDirections();
 172                         $this->mDefaultDirection = is_array( $dir )
 173                                 ? $dir[$this->mOrderType]
 174                                 : $dir;
 175                 }
 176         }
 177
 178         /**
 179          * Do the query, using information from the object context. This function
 180          * has been kept minimal to make it overridable if necessary, to allow for
 181          * result sets formed from multiple DB queries.
 182          */
 183         public function doQuery() {
 184                 # Use the child class name for profiling
 185                 $fname = __METHOD__ . ' (' . get_class( $this ) . ')';
 186                 wfProfileIn( $fname );
 187
 188                 $descending = ( $this->mIsBackwards == $this->mDefaultDirection );
 189                 # Plus an extra row so that we can tell the "next" link should be shown
 190                 $queryLimit = $this->mLimit + 1;
 191
 192                 $this->mResult = $this->reallyDoQuery(
 193                         $this->mOffset,
 194                         $queryLimit,
 195                         $descending
 196                 );
 197
 198                 $this->extractResultInfo( $this->mOffset, $queryLimit, $this->mResult );
 199                 $this->mQueryDone = true;
 200
 201                 $this->preprocessResults( $this->mResult );
 202                 $this->mResult->rewind(); // Paranoia
 203
 204                 wfProfileOut( $fname );
 205         }
 206
 207         /**
 208          * @return ResultWrapper The result wrapper.
 209          */
 210         function getResult() {
 211                 return $this->mResult;
 212         }
 213
 214         /**
 215          * Set the offset from an other source than the request
 216          *
 217          * @param $offset Int|String
 218          */
 219         function setOffset( $offset ) {
 220                 $this->mOffset = $offset;
 221         }
 222         /**
 223          * Set the limit from an other source than the request
 224          *
 225          * @param $limit Int|String
 226          */
 227         function setLimit( $limit ) {
 228                 $this->mLimit = $limit;
 229         }
 230
 231         /**
 232          * Extract some useful data from the result object for use by
 233          * the navigation bar, put it into $this
 234          *
 235          * @param $offset String: index offset, inclusive
 236          * @param $limit Integer: exact query limit
 237          * @param $res ResultWrapper
 238          */
 239         function extractResultInfo( $offset, $limit, ResultWrapper $res ) {
 240                 $numRows = $res->numRows();
 241                 if ( $numRows ) {
 242                         # Remove any table prefix from index field
 243                         $parts = explode( '.', $this->mIndexField );
 244                         $indexColumn = end( $parts );
 245
 246                         $row = $res->fetchRow();
 247                         $firstIndex = $row[$indexColumn];
 248
 249                         # Discard the extra result row if there is one
 250                         if ( $numRows > $this->mLimit && $numRows > 1 ) {
 251                                 $res->seek( $numRows - 1 );
 252                                 $this->mPastTheEndRow = $res->fetchObject();
 253                                 $indexField = $this->mIndexField;
 254                                 $this->mPastTheEndIndex = $this->mPastTheEndRow->$indexField;
 255                                 $res->seek( $numRows - 2 );
 256                                 $row = $res->fetchRow();
 257                                 $lastIndex = $row[$indexColumn];
 258                         } else {
 259                                 $this->mPastTheEndRow = null;
 260                                 # Setting indexes to an empty string means that they will be
 261                                 # omitted if they would otherwise appear in URLs. It just so
 262                                 # happens that this  is the right thing to do in the standard
 263                                 # UI, in all the relevant cases.
 264                                 $this->mPastTheEndIndex = '';
 265                                 $res->seek( $numRows - 1 );
 266                                 $row = $res->fetchRow();
 267                                 $lastIndex = $row[$indexColumn];
 268                         }
 269                 } else {
 270                         $firstIndex = '';
 271                         $lastIndex = '';
 272                         $this->mPastTheEndRow = null;
 273                         $this->mPastTheEndIndex = '';
 274                 }
 275
 276                 if ( $this->mIsBackwards ) {
 277                         $this->mIsFirst = ( $numRows < $limit );
 278                         $this->mIsLast = ( $offset == '' );
 279                         $this->mLastShown = $firstIndex;
 280                         $this->mFirstShown = $lastIndex;
 281                 } else {
 282                         $this->mIsFirst = ( $offset == '' );
 283                         $this->mIsLast = ( $numRows < $limit );
 284                         $this->mLastShown = $lastIndex;
 285                         $this->mFirstShown = $firstIndex;
 286                 }
 287         }
 288
 289         /**
 290          * Get some text to go in brackets in the "function name" part of the SQL comment
 291          *
 292          * @return String
 293          */
 294         function getSqlComment() {
 295                 return get_class( $this );
 296         }
 297
 298         /**
 299          * Do a query with specified parameters, rather than using the object
 300          * context
 301          *
 302          * @param $offset String: index offset, inclusive
 303          * @param $limit Integer: exact query limit
 304          * @param $descending Boolean: query direction, false for ascending, true for descending
 305          * @return ResultWrapper
 306          */
 307         public function reallyDoQuery( $offset, $limit, $descending ) {
 308                 list( $tables, $fields, $conds, $fname, $options, $join_conds ) = $this->buildQueryInfo( $offset, $limit, $descending );
 309                 return $this->mDb->select( $tables, $fields, $conds, $fname, $options, $join_conds );
 310         }
 311
 312         /**
 313          * Build variables to use by the database wrapper.
 314          *
 315          * @param $offset String: index offset, inclusive
 316          * @param $limit Integer: exact query limit
 317          * @param $descending Boolean: query direction, false for ascending, true for descending
 318          * @return array
 319          */
 320         protected function buildQueryInfo( $offset, $limit, $descending ) {
 321                 $fname = __METHOD__ . ' (' . $this->getSqlComment() . ')';
 322                 $info = $this->getQueryInfo();
 323                 $tables = $info['tables'];
 324                 $fields = $info['fields'];
 325                 $conds = isset( $info['conds'] ) ? $info['conds'] : array();
 326                 $options = isset( $info['options'] ) ? $info['options'] : array();
 327                 $join_conds = isset( $info['join_conds'] ) ? $info['join_conds'] : array();
 328                 $sortColumns = array_merge( array( $this->mIndexField ), $this->mExtraSortFields );
 329                 if ( $descending ) {
 330                         $options['ORDER BY'] = $sortColumns;
 331                         $operator = '>';
 332                 } else {
 333                         $orderBy = array();
 334                         foreach ( $sortColumns as $col ) {
 335                                 $orderBy[] = $col . ' DESC';
 336                         }
 337                         $options['ORDER BY'] = $orderBy;
 338                         $operator = '<';
 339                 }
 340                 if ( $offset != '' ) {
 341                         $conds[] = $this->mIndexField . $operator . $this->mDb->addQuotes( $offset );
 342                 }
 343                 $options['LIMIT'] = intval( $limit );
 344                 return array( $tables, $fields, $conds, $fname, $options, $join_conds );
 345         }
 346
 347         /**
 348          * Pre-process results; useful for performing batch existence checks, etc.
 349          *
 350          * @param $result ResultWrapper
 351          */
 352         protected function preprocessResults( $result ) {}
 353
 354         /**
 355          * Get the formatted result list. Calls getStartBody(), formatRow() and
 356          * getEndBody(), concatenates the results and returns them.
 357          *
 358          * @return String
 359          */
 360         public function getBody() {
 361                 if ( !$this->mQueryDone ) {
 362                         $this->doQuery();
 363                 }
 364
 365                 if ( $this->mResult->numRows() ) {
 366                         # Do any special query batches before display
 367                         $this->doBatchLookups();
 368                 }
 369
 370                 # Don't use any extra rows returned by the query
 371                 $numRows = min( $this->mResult->numRows(), $this->mLimit );
 372
 373                 $s = $this->getStartBody();
 374                 if ( $numRows ) {
 375                         if ( $this->mIsBackwards ) {
 376                                 for ( $i = $numRows - 1; $i >= 0; $i-- ) {
 377                                         $this->mResult->seek( $i );
 378                                         $row = $this->mResult->fetchObject();
 379                                         $s .= $this->formatRow( $row );
 380                                 }
 381                         } else {
 382                                 $this->mResult->seek( 0 );
 383                                 for ( $i = 0; $i < $numRows; $i++ ) {
 384                                         $row = $this->mResult->fetchObject();
 385                                         $s .= $this->formatRow( $row );
 386                                 }
 387                         }
 388                 } else {
 389                         $s .= $this->getEmptyBody();
 390                 }
 391                 $s .= $this->getEndBody();
 392                 return $s;
 393         }
 394
 395         /**
 396          * Make a self-link
 397          *
 398          * @param $text String: text displayed on the link
 399          * @param $query Array: associative array of paramter to be in the query string
 400          * @param $type String: value of the "rel" attribute
 401          *
 402          * @return String: HTML fragment
 403          */
 404         function makeLink( $text, array $query = null, $type = null ) {
 405                 if ( $query === null ) {
 406                         return $text;
 407                 }
 408
 409                 $attrs = array();
 410                 if( in_array( $type, array( 'first', 'prev', 'next', 'last' ) ) ) {
 411                         # HTML5 rel attributes
 412                         $attrs['rel'] = $type;
 413                 }
 414
 415                 if( $type ) {
 416                         $attrs['class'] = "mw-{$type}link";
 417                 }
 418
 419                 return Linker::linkKnown(
 420                         $this->getTitle(),
 421                         $text,
 422                         $attrs,
 423                         $query + $this->getDefaultQuery()
 424                 );
 425         }
 426
 427         /**
 428          * Called from getBody(), before getStartBody() is called and
 429          * after doQuery() was called. This will be called only if there
 430          * are rows in the result set.
 431          *
 432          * @return void
 433          */
 434         protected function doBatchLookups() {}
 435
 436         /**
 437          * Hook into getBody(), allows text to be inserted at the start. This
 438          * will be called even if there are no rows in the result set.
 439          *
 440          * @return String
 441          */
 442         protected function getStartBody() {
 443                 return '';
 444         }
 445
 446         /**
 447          * Hook into getBody() for the end of the list
 448          *
 449          * @return String
 450          */
 451         protected function getEndBody() {
 452                 return '';
 453         }
 454
 455         /**
 456          * Hook into getBody(), for the bit between the start and the
 457          * end when there are no rows
 458          *
 459          * @return String
 460          */
 461         protected function getEmptyBody() {
 462                 return '';
 463         }
 464
 465         /**
 466          * Get an array of query parameters that should be put into self-links.
 467          * By default, all parameters passed in the URL are used, except for a
 468          * short blacklist.
 469          *
 470          * @return array Associative array
 471          */
 472         function getDefaultQuery() {
 473                 if ( !isset( $this->mDefaultQuery ) ) {
 474                         $this->mDefaultQuery = $this->getRequest()->getQueryValues();
 475                         unset( $this->mDefaultQuery['title'] );
 476                         unset( $this->mDefaultQuery['dir'] );
 477                         unset( $this->mDefaultQuery['offset'] );
 478                         unset( $this->mDefaultQuery['limit'] );
 479                         unset( $this->mDefaultQuery['order'] );
 480                         unset( $this->mDefaultQuery['month'] );
 481                         unset( $this->mDefaultQuery['year'] );
 482                 }
 483                 return $this->mDefaultQuery;
 484         }
 485
 486         /**
 487          * Get the number of rows in the result set
 488          *
 489          * @return Integer
 490          */
 491         function getNumRows() {
 492                 if ( !$this->mQueryDone ) {
 493                         $this->doQuery();
 494                 }
 495                 return $this->mResult->numRows();
 496         }
 497
 498         /**
 499          * Get a URL query array for the prev, next, first and last links.
 500          *
 501          * @return Array
 502          */
 503         function getPagingQueries() {
 504                 if ( !$this->mQueryDone ) {
 505                         $this->doQuery();
 506                 }
 507
 508                 # Don't announce the limit everywhere if it's the default
 509                 $urlLimit = $this->mLimit == $this->mDefaultLimit ? null : $this->mLimit;
 510
 511                 if ( $this->mIsFirst ) {
 512                         $prev = false;
 513                         $first = false;
 514                 } else {
 515                         $prev = array(
 516                                 'dir' => 'prev',
 517                                 'offset' => $this->mFirstShown,
 518                                 'limit' => $urlLimit
 519                         );
 520                         $first = array( 'limit' => $urlLimit );
 521                 }
 522                 if ( $this->mIsLast ) {
 523                         $next = false;
 524                         $last = false;
 525                 } else {
 526                         $next = array( 'offset' => $this->mLastShown, 'limit' => $urlLimit );
 527                         $last = array( 'dir' => 'prev', 'limit' => $urlLimit );
 528                 }
 529                 return array(
 530                         'prev' => $prev,
 531                         'next' => $next,
 532                         'first' => $first,
 533                         'last' => $last
 534                 );
 535         }
 536
 537         /**
 538          * Returns whether to show the "navigation bar"
 539          *
 540          * @return Boolean
 541          */
 542         function isNavigationBarShown() {
 543                 if ( !$this->mQueryDone ) {
 544                         $this->doQuery();
 545                 }
 546                 // Hide navigation by default if there is nothing to page
 547                 return !($this->mIsFirst && $this->mIsLast);
 548         }
 549
 550         /**
 551          * Get paging links. If a link is disabled, the item from $disabledTexts
 552          * will be used. If there is no such item, the unlinked text from
 553          * $linkTexts will be used. Both $linkTexts and $disabledTexts are arrays
 554          * of HTML.
 555          *
 556          * @param $linkTexts Array
 557          * @param $disabledTexts Array
 558          * @return Array
 559          */
 560         function getPagingLinks( $linkTexts, $disabledTexts = array() ) {
 561                 $queries = $this->getPagingQueries();
 562                 $links = array();
 563
 564                 foreach ( $queries as $type => $query ) {
 565                         if ( $query !== false ) {
 566                                 $links[$type] = $this->makeLink(
 567                                         $linkTexts[$type],
 568                                         $queries[$type],
 569                                         $type
 570                                 );
 571                         } elseif ( isset( $disabledTexts[$type] ) ) {
 572                                 $links[$type] = $disabledTexts[$type];
 573                         } else {
 574                                 $links[$type] = $linkTexts[$type];
 575                         }
 576                 }
 577
 578                 return $links;
 579         }
 580
 581         function getLimitLinks() {
 582                 $links = array();
 583                 if ( $this->mIsBackwards ) {
 584                         $offset = $this->mPastTheEndIndex;
 585                 } else {
 586                         $offset = $this->mOffset;
 587                 }
 588                 foreach ( $this->mLimitsShown as $limit ) {
 589                         $links[] = $this->makeLink(
 590                                 $this->getLanguage()->formatNum( $limit ),
 591                                 array( 'offset' => $offset, 'limit' => $limit ),
 592                                 'num'
 593                         );
 594                 }
 595                 return $links;
 596         }
 597
 598         /**
 599          * Abstract formatting function. This should return an HTML string
 600          * representing the result row $row. Rows will be concatenated and
 601          * returned by getBody()
 602          *
 603          * @param $row Object: database row
 604          * @return String
 605          */
 606         abstract function formatRow( $row );
 607
 608         /**
 609          * This function should be overridden to provide all parameters
 610          * needed for the main paged query. It returns an associative
 611          * array with the following elements:
 612          *    tables => Table(s) for passing to Database::select()
 613          *    fields => Field(s) for passing to Database::select(), may be *
 614          *    conds => WHERE conditions
 615          *    options => option array
 616          *    join_conds => JOIN conditions
 617          *
 618          * @return Array
 619          */
 620         abstract function getQueryInfo();
 621
 622         /**
 623          * This function should be overridden to return the name of the index fi-
 624          * eld.  If the pager supports multiple orders, it may return an array of
 625          * 'querykey' => 'indexfield' pairs, so that a request with &count=querykey
 626          * will use indexfield to sort.  In this case, the first returned key is
 627          * the default.
 628          *
 629          * Needless to say, it's really not a good idea to use a non-unique index
 630          * for this!  That won't page right.
 631          *
 632          * @return string|Array
 633          */
 634         abstract function getIndexField();
 635
 636         /**
 637          * This function should be overridden to return the names of secondary columns
 638          * to order by in addition to the column in getIndexField(). These fields will
 639          * not be used in the pager offset or in any links for users.
 640          *
 641          * If getIndexField() returns an array of 'querykey' => 'indexfield' pairs then
 642          * this must return a corresponding array of 'querykey' => array( fields...) pairs
 643          * in order for a request with &count=querykey to use array( fields...) to sort.
 644          *
 645          * This is useful for pagers that GROUP BY a unique column (say page_id)
 646          * and ORDER BY another (say page_len). Using GROUP BY and ORDER BY both on
 647          * page_len,page_id avoids temp tables (given a page_len index). This would
 648          * also work if page_id was non-unique but we had a page_len,page_id index.
 649          *
 650          * @return Array
 651          */
 652         protected function getExtraSortFields() { return array(); }
 653
 654         /**
 655          * Return the default sorting direction: false for ascending, true for de-
 656          * scending.  You can also have an associative array of ordertype => dir,
 657          * if multiple order types are supported.  In this case getIndexField()
 658          * must return an array, and the keys of that must exactly match the keys
 659          * of this.
 660          *
 661          * For backward compatibility, this method's return value will be ignored
 662          * if $this->mDefaultDirection is already set when the constructor is
 663          * called, for instance if it's statically initialized.  In that case the
 664          * value of that variable (which must be a boolean) will be used.
 665          *
 666          * Note that despite its name, this does not return the value of the
 667          * $this->mDefaultDirection member variable.  That's the default for this
 668          * particular instantiation, which is a single value.  This is the set of
 669          * all defaults for the class.
 670          *
 671          * @return Boolean
 672          */
 673         protected function getDefaultDirections() { return false; }
 674 }
 675
 676
 677 /**
 678  * IndexPager with an alphabetic list and a formatted navigation bar
 679  * @ingroup Pager
 680  */
 681 abstract class AlphabeticPager extends IndexPager {
 682
 683         /**
 684          * Shamelessly stolen bits from ReverseChronologicalPager,
 685          * didn't want to do class magic as may be still revamped
 686          *
 687          * @return String HTML
 688          */
 689         function getNavigationBar() {
 690                 if ( !$this->isNavigationBarShown() ) {
 691                         return '';
 692                 }
 693
 694                 if( isset( $this->mNavigationBar ) ) {
 695                         return $this->mNavigationBar;
 696                 }
 697
 698                 $linkTexts = array(
 699                         'prev' => $this->msg( 'prevn' )->numParams( $this->mLimit )->escaped(),
 700                         'next' => $this->msg( 'nextn' )->numParams( $this->mLimit )->escaped(),
 701                         'first' => $this->msg( 'page_first' )->escaped(),
 702                         'last' => $this->msg( 'page_last' )->escaped()
 703                 );
 704
 705                 $lang = $this->getLanguage();
 706
 707                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 708                 $limitLinks = $this->getLimitLinks();
 709                 $limits = $lang->pipeList( $limitLinks );
 710
 711                 $this->mNavigationBar = $this->msg( 'parentheses' )->rawParams(
 712                         $lang->pipeList( array( $pagingLinks['first'],
 713                         $pagingLinks['last'] ) ) )->escaped() . " " .
 714                         $this->msg( 'viewprevnext' )->rawParams( $pagingLinks['prev'],
 715                                 $pagingLinks['next'], $limits )->escaped();
 716
 717                 if( !is_array( $this->getIndexField() ) ) {
 718                         # Early return to avoid undue nesting
 719                         return $this->mNavigationBar;
 720                 }
 721
 722                 $extra = '';
 723                 $first = true;
 724                 $msgs = $this->getOrderTypeMessages();
 725                 foreach( array_keys( $msgs ) as $order ) {
 726                         if( $first ) {
 727                                 $first = false;
 728                         } else {
 729                                 $extra .= $this->msg( 'pipe-separator' )->escaped();
 730                         }
 731
 732                         if( $order == $this->mOrderType ) {
 733                                 $extra .= $this->msg( $msgs[$order] )->escaped();
 734                         } else {
 735                                 $extra .= $this->makeLink(
 736                                         $this->msg( $msgs[$order] )->escaped(),
 737                                         array( 'order' => $order )
 738                                 );
 739                         }
 740                 }
 741
 742                 if( $extra !== '' ) {
 743                         $extra = ' ' . $this->msg( 'parentheses' )->rawParams( $extra )->escaped();
 744                         $this->mNavigationBar .= $extra;
 745                 }
 746
 747                 return $this->mNavigationBar;
 748         }
 749
 750         /**
 751          * If this supports multiple order type messages, give the message key for
 752          * enabling each one in getNavigationBar.  The return type is an associa-
 753          * tive array whose keys must exactly match the keys of the array returned
 754          * by getIndexField(), and whose values are message keys.
 755          *
 756          * @return Array
 757          */
 758         protected function getOrderTypeMessages() {
 759                 return null;
 760         }
 761 }
 762
 763 /**
 764  * IndexPager with a formatted navigation bar
 765  * @ingroup Pager
 766  */
 767 abstract class ReverseChronologicalPager extends IndexPager {
 768         public $mDefaultDirection = true;
 769         public $mYear;
 770         public $mMonth;
 771
 772         function getNavigationBar() {
 773                 if ( !$this->isNavigationBarShown() ) {
 774                         return '';
 775                 }
 776
 777                 if ( isset( $this->mNavigationBar ) ) {
 778                         return $this->mNavigationBar;
 779                 }
 780
 781                 $linkTexts = array(
 782                         'prev' => $this->msg( 'pager-newer-n' )->numParams( $this->mLimit )->escaped(),
 783                         'next' => $this->msg( 'pager-older-n' )->numParams( $this->mLimit )->escaped(),
 784                         'first' => $this->msg( 'histlast' )->escaped(),
 785                         'last' => $this->msg( 'histfirst' )->escaped()
 786                 );
 787
 788                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 789                 $limitLinks = $this->getLimitLinks();
 790                 $limits = $this->getLanguage()->pipeList( $limitLinks );
 791                 $firstLastLinks = $this->msg( 'parentheses' )->rawParams( "{$pagingLinks['first']}" .
 792                         $this->msg( 'pipe-separator' )->escaped() .
 793                         "{$pagingLinks['last']}" )->escaped();
 794
 795                 $this->mNavigationBar = $firstLastLinks . ' ' .
 796                         $this->msg( 'viewprevnext' )->rawParams(
 797                                 $pagingLinks['prev'], $pagingLinks['next'], $limits )->escaped();
 798
 799                 return $this->mNavigationBar;
 800         }
 801
 802         function getDateCond( $year, $month ) {
 803                 $year = intval( $year );
 804                 $month = intval( $month );
 805
 806                 // Basic validity checks
 807                 $this->mYear = $year > 0 ? $year : false;
 808                 $this->mMonth = ( $month > 0 && $month < 13 ) ? $month : false;
 809
 810                 // Given an optional year and month, we need to generate a timestamp
 811                 // to use as "WHERE rev_timestamp <= result"
 812                 // Examples: year = 2006 equals < 20070101 (+000000)
 813                 // year=2005, month=1    equals < 20050201
 814                 // year=2005, month=12   equals < 20060101
 815                 if ( !$this->mYear && !$this->mMonth ) {
 816                         return;
 817                 }
 818
 819                 if ( $this->mYear ) {
 820                         $year = $this->mYear;
 821                 } else {
 822                         // If no year given, assume the current one
 823                         $year = gmdate( 'Y' );
 824                         // If this month hasn't happened yet this year, go back to last year's month
 825                         if( $this->mMonth > gmdate( 'n' ) ) {
 826                                 $year--;
 827                         }
 828                 }
 829
 830                 if ( $this->mMonth ) {
 831                         $month = $this->mMonth + 1;
 832                         // For December, we want January 1 of the next year
 833                         if ($month > 12) {
 834                                 $month = 1;
 835                                 $year++;
 836                         }
 837                 } else {
 838                         // No month implies we want up to the end of the year in question
 839                         $month = 1;
 840                         $year++;
 841                 }
 842
 843                 // Y2K38 bug
 844                 if ( $year > 2032 ) {
 845                         $year = 2032;
 846                 }
 847
 848                 $ymd = (int)sprintf( "%04d%02d01", $year, $month );
 849
 850                 if ( $ymd > 20320101 ) {
 851                         $ymd = 20320101;
 852                 }
 853
 854                 $this->mOffset = $this->mDb->timestamp( "${ymd}000000" );
 855         }
 856 }
 857
 858 /**
 859  * Table-based display with a user-selectable sort order
 860  * @ingroup Pager
 861  */
 862 abstract class TablePager extends IndexPager {
 863         var $mSort;
 864         var $mCurrentRow;
 865
 866         public function __construct( IContextSource $context = null ) {
 867                 if ( $context ) {
 868                         $this->setContext( $context );
 869                 }
 870
 871                 $this->mSort = $this->getRequest()->getText( 'sort' );
 872                 if ( !array_key_exists( $this->mSort, $this->getFieldNames() ) ) {
 873                         $this->mSort = $this->getDefaultSort();
 874                 }
 875                 if ( $this->getRequest()->getBool( 'asc' ) ) {
 876                         $this->mDefaultDirection = false;
 877                 } elseif ( $this->getRequest()->getBool( 'desc' ) ) {
 878                         $this->mDefaultDirection = true;
 879                 } /* Else leave it at whatever the class default is */
 880
 881                 parent::__construct();
 882         }
 883
 884         /**
 885          * @protected
 886          * @return string
 887          */
 888         function getStartBody() {
 889                 global $wgStylePath;
 890                 $tableClass = htmlspecialchars( $this->getTableClass() );
 891                 $sortClass = htmlspecialchars( $this->getSortHeaderClass() );
 892
 893                 $s = "<table style='border:1;' class=\"mw-datatable $tableClass\"><thead><tr>\n";
 894                 $fields = $this->getFieldNames();
 895
 896                 # Make table header
 897                 foreach ( $fields as $field => $name ) {
 898                         if ( strval( $name ) == '' ) {
 899                                 $s .= "<th>&#160;</th>\n";
 900                         } elseif ( $this->isFieldSortable( $field ) ) {
 901                                 $query = array( 'sort' => $field, 'limit' => $this->mLimit );
 902                                 if ( $field == $this->mSort ) {
 903                                         # This is the sorted column
 904                                         # Prepare a link that goes in the other sort order
 905                                         if ( $this->mDefaultDirection ) {
 906                                                 # Descending
 907                                                 $image = 'Arr_d.png';
 908                                                 $query['asc'] = '1';
 909                                                 $query['desc'] = '';
 910                                                 $alt = $this->msg( 'descending_abbrev' )->escaped();
 911                                         } else {
 912                                                 # Ascending
 913                                                 $image = 'Arr_u.png';
 914                                                 $query['asc'] = '';
 915                                                 $query['desc'] = '1';
 916                                                 $alt = $this->msg( 'ascending_abbrev' )->escaped();
 917                                         }
 918                                         $image = htmlspecialchars( "$wgStylePath/common/images/$image" );
 919                                         $link = $this->makeLink(
 920                                                 "<img width=\"12\" height=\"12\" alt=\"$alt\" src=\"$image\" />" .
 921                                                         htmlspecialchars( $name ), $query );
 922                                         $s .= "<th class=\"$sortClass\">$link</th>\n";
 923                                 } else {
 924                                         $s .= '<th>' . $this->makeLink( htmlspecialchars( $name ), $query ) . "</th>\n";
 925                                 }
 926                         } else {
 927                                 $s .= '<th>' . htmlspecialchars( $name ) . "</th>\n";
 928                         }
 929                 }
 930                 $s .= "</tr></thead><tbody>\n";
 931                 return $s;
 932         }
 933
 934         /**
 935          * @protected
 936          * @return string
 937          */
 938         function getEndBody() {
 939                 return "</tbody></table>\n";
 940         }
 941
 942         /**
 943          * @protected
 944          * @return string
 945          */
 946         function getEmptyBody() {
 947                 $colspan = count( $this->getFieldNames() );
 948                 $msgEmpty = $this->msg( 'table_pager_empty' )->escaped();
 949                 return "<tr><td colspan=\"$colspan\">$msgEmpty</td></tr>\n";
 950         }
 951
 952         /**
 953          * @protected
 954          * @param stdClass $row
 955          * @return String HTML
 956          */
 957         function formatRow( $row ) {
 958                 $this->mCurrentRow = $row; // In case formatValue etc need to know
 959                 $s = Xml::openElement( 'tr', $this->getRowAttrs( $row ) );
 960                 $fieldNames = $this->getFieldNames();
 961
 962                 foreach ( $fieldNames as $field => $name ) {
 963                         $value = isset( $row->$field ) ? $row->$field : null;
 964                         $formatted = strval( $this->formatValue( $field, $value ) );
 965
 966                         if ( $formatted == '' ) {
 967                                 $formatted = '&#160;';
 968                         }
 969
 970                         $s .= Xml::tags( 'td', $this->getCellAttrs( $field, $value ), $formatted );
 971                 }
 972
 973                 $s .= "</tr>\n";
 974
 975                 return $s;
 976         }
 977
 978         /**
 979          * Get a class name to be applied to the given row.
 980          *
 981          * @protected
 982          *
 983          * @param $row Object: the database result row
 984          * @return String
 985          */
 986         function getRowClass( $row ) {
 987                 return '';
 988         }
 989
 990         /**
 991          * Get attributes to be applied to the given row.
 992          *
 993          * @protected
 994          *
 995          * @param $row Object: the database result row
 996          * @return Array of <attr> => <value>
 997          */
 998         function getRowAttrs( $row ) {
 999                 $class = $this->getRowClass( $row );
1000                 if ( $class === '' ) {
1001                         // Return an empty array to avoid clutter in HTML like class=""
1002                         return array();
1003                 } else {
1004                         return array( 'class' => $this->getRowClass( $row ) );
1005                 }
1006         }
1007
1008         /**
1009          * Get any extra attributes to be applied to the given cell. Don't
1010          * take this as an excuse to hardcode styles; use classes and
1011          * CSS instead.  Row context is available in $this->mCurrentRow
1012          *
1013          * @protected
1014          *
1015          * @param $field String The column
1016          * @param $value String The cell contents
1017          * @return Array of attr => value
1018          */
1019         function getCellAttrs( $field, $value ) {
1020                 return array( 'class' => 'TablePager_col_' . $field );
1021         }
1022
1023         /**
1024          * @protected
1025          * @return string
1026          */
1027         function getIndexField() {
1028                 return $this->mSort;
1029         }
1030
1031         /**
1032          * @protected
1033          * @return string
1034          */
1035         function getTableClass() {
1036                 return 'TablePager';
1037         }
1038
1039         /**
1040          * @protected
1041          * @return string
1042          */
1043         function getNavClass() {
1044                 return 'TablePager_nav';
1045         }
1046
1047         /**
1048          * @protected
1049          * @return string
1050          */
1051         function getSortHeaderClass() {
1052                 return 'TablePager_sort';
1053         }
1054
1055         /**
1056          * A navigation bar with images
1057          * @return String HTML
1058          */
1059         public function getNavigationBar() {
1060                 global $wgStylePath;
1061
1062                 if ( !$this->isNavigationBarShown() ) {
1063                         return '';
1064                 }
1065
1066                 $path = "$wgStylePath/common/images";
1067                 $labels = array(
1068                         'first' => 'table_pager_first',
1069                         'prev' => 'table_pager_prev',
1070                         'next' => 'table_pager_next',
1071                         'last' => 'table_pager_last',
1072                 );
1073                 $images = array(
1074                         'first' => 'arrow_first_25.png',
1075                         'prev' => 'arrow_left_25.png',
1076                         'next' => 'arrow_right_25.png',
1077                         'last' => 'arrow_last_25.png',
1078                 );
1079                 $disabledImages = array(
1080                         'first' => 'arrow_disabled_first_25.png',
1081                         'prev' => 'arrow_disabled_left_25.png',
1082                         'next' => 'arrow_disabled_right_25.png',
1083                         'last' => 'arrow_disabled_last_25.png',
1084                 );
1085                 if( $this->getLanguage()->isRTL() ) {
1086                         $keys = array_keys( $labels );
1087                         $images = array_combine( $keys, array_reverse( $images ) );
1088                         $disabledImages = array_combine( $keys, array_reverse( $disabledImages ) );
1089                 }
1090
1091                 $linkTexts = array();
1092                 $disabledTexts = array();
1093                 foreach ( $labels as $type => $label ) {
1094                         $msgLabel = $this->msg( $label )->escaped();
1095                         $linkTexts[$type] = "<img src=\"$path/{$images[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
1096                         $disabledTexts[$type] = "<img src=\"$path/{$disabledImages[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
1097                 }
1098                 $links = $this->getPagingLinks( $linkTexts, $disabledTexts );
1099
1100                 $navClass = htmlspecialchars( $this->getNavClass() );
1101                 $s = "<table class=\"$navClass\"><tr>\n";
1102                 $width = 100 / count( $links ) . '%';
1103                 foreach ( $labels as $type => $label ) {
1104                         $s .= "<td style='width:$width;'>{$links[$type]}</td>\n";
1105                 }
1106                 $s .= "</tr></table>\n";
1107                 return $s;
1108         }
1109
1110         /**
1111          * Get a <select> element which has options for each of the allowed limits
1112          *
1113          * @return String: HTML fragment
1114          */
1115         public function getLimitSelect() {
1116                 # Add the current limit from the query string
1117                 # to avoid that the limit is lost after clicking Go next time
1118                 if ( !in_array( $this->mLimit, $this->mLimitsShown ) ) {
1119                         $this->mLimitsShown[] = $this->mLimit;
1120                         sort( $this->mLimitsShown );
1121                 }
1122                 $s = Html::openElement( 'select', array( 'name' => 'limit' ) ) . "\n";
1123                 foreach ( $this->mLimitsShown as $key => $value ) {
1124                         # The pair is either $index => $limit, in which case the $value
1125                         # will be numeric, or $limit => $text, in which case the $value
1126                         # will be a string.
1127                         if( is_int( $value ) ){
1128                                 $limit = $value;
1129                                 $text = $this->getLanguage()->formatNum( $limit );
1130                         } else {
1131                                 $limit = $key;
1132                                 $text = $value;
1133                         }
1134                         $s .= Xml::option( $text, $limit, $limit == $this->mLimit ) . "\n";
1135                 }
1136                 $s .= Html::closeElement( 'select' );
1137                 return $s;
1138         }
1139
1140         /**
1141          * Get <input type="hidden"> elements for use in a method="get" form.
1142          * Resubmits all defined elements of the query string, except for a
1143          * blacklist, passed in the $blacklist parameter.
1144          *
1145          * @param $blacklist Array parameters from the request query which should not be resubmitted
1146          * @return String: HTML fragment
1147          */
1148         function getHiddenFields( $blacklist = array() ) {
1149                 $blacklist = (array)$blacklist;
1150                 $query = $this->getRequest()->getQueryValues();
1151                 foreach ( $blacklist as $name ) {
1152                         unset( $query[$name] );
1153                 }
1154                 $s = '';
1155                 foreach ( $query as $name => $value ) {
1156                         $encName = htmlspecialchars( $name );
1157                         $encValue = htmlspecialchars( $value );
1158                         $s .= "<input type=\"hidden\" name=\"$encName\" value=\"$encValue\"/>\n";
1159                 }
1160                 return $s;
1161         }
1162
1163         /**
1164          * Get a form containing a limit selection dropdown
1165          *
1166          * @return String: HTML fragment
1167          */
1168         function getLimitForm() {
1169                 global $wgScript;
1170
1171                 return Xml::openElement(
1172                         'form',
1173                         array(
1174                                 'method' => 'get',
1175                                 'action' => $wgScript
1176                         ) ) . "\n" . $this->getLimitDropdown() . "</form>\n";
1177         }
1178
1179         /**
1180          * Gets a limit selection dropdown
1181          *
1182          * @return string
1183          */
1184         function getLimitDropdown() {
1185                 # Make the select with some explanatory text
1186                 $msgSubmit = $this->msg( 'table_pager_limit_submit' )->escaped();
1187
1188                 return $this->msg( 'table_pager_limit' )
1189                         ->rawParams( $this->getLimitSelect() )->escaped() .
1190                         "\n<input type=\"submit\" value=\"$msgSubmit\"/>\n" .
1191                         $this->getHiddenFields( array( 'limit' ) );
1192         }
1193
1194         /**
1195          * Return true if the named field should be sortable by the UI, false
1196          * otherwise
1197          *
1198          * @param $field String
1199          */
1200         abstract function isFieldSortable( $field );
1201
1202         /**
1203          * Format a table cell. The return value should be HTML, but use an empty
1204          * string not &#160; for empty cells. Do not include the <td> and </td>.
1205          *
1206          * The current result row is available as $this->mCurrentRow, in case you
1207          * need more context.
1208          *
1209          * @protected
1210          *
1211          * @param $name String: the database field name
1212          * @param $value String: the value retrieved from the database
1213          */
1214         abstract function formatValue( $name, $value );
1215
1216         /**
1217          * The database field name used as a default sort order.
1218          *
1219          * @protected
1220          *
1221          * @return string
1222          */
1223         abstract function getDefaultSort();
1224
1225         /**
1226          * An array mapping database field names to a textual description of the
1227          * field name, for use in the table header. The description should be plain
1228          * text, it will be HTML-escaped later.
1229          *
1230          * @return Array
1231          */
1232         abstract function getFieldNames();
1233 }