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                 $result = $this->mDb->select( $tables, $fields, $conds, $fname, $options, $join_conds );
 310                 return new ResultWrapper( $this->mDb, $result );
 311         }
 312
 313         /**
 314          * Build variables to use by the database wrapper.
 315          *
 316          * @param $offset String: index offset, inclusive
 317          * @param $limit Integer: exact query limit
 318          * @param $descending Boolean: query direction, false for ascending, true for descending
 319          * @return array
 320          */
 321         protected function buildQueryInfo( $offset, $limit, $descending ) {
 322                 $fname = __METHOD__ . ' (' . $this->getSqlComment() . ')';
 323                 $info = $this->getQueryInfo();
 324                 $tables = $info['tables'];
 325                 $fields = $info['fields'];
 326                 $conds = isset( $info['conds'] ) ? $info['conds'] : array();
 327                 $options = isset( $info['options'] ) ? $info['options'] : array();
 328                 $join_conds = isset( $info['join_conds'] ) ? $info['join_conds'] : array();
 329                 $sortColumns = array_merge( array( $this->mIndexField ), $this->mExtraSortFields );
 330                 if ( $descending ) {
 331                         $options['ORDER BY'] = $sortColumns;
 332                         $operator = '>';
 333                 } else {
 334                         $orderBy = array();
 335                         foreach ( $sortColumns as $col ) {
 336                                 $orderBy[] = $col . ' DESC';
 337                         }
 338                         $options['ORDER BY'] = $orderBy;
 339                         $operator = '<';
 340                 }
 341                 if ( $offset != '' ) {
 342                         $conds[] = $this->mIndexField . $operator . $this->mDb->addQuotes( $offset );
 343                 }
 344                 $options['LIMIT'] = intval( $limit );
 345                 return array( $tables, $fields, $conds, $fname, $options, $join_conds );
 346         }
 347
 348         /**
 349          * Pre-process results; useful for performing batch existence checks, etc.
 350          *
 351          * @param $result ResultWrapper
 352          */
 353         protected function preprocessResults( $result ) {}
 354
 355         /**
 356          * Get the formatted result list. Calls getStartBody(), formatRow() and
 357          * getEndBody(), concatenates the results and returns them.
 358          *
 359          * @return String
 360          */
 361         public function getBody() {
 362                 if ( !$this->mQueryDone ) {
 363                         $this->doQuery();
 364                 }
 365
 366                 if ( $this->mResult->numRows() ) {
 367                         # Do any special query batches before display
 368                         $this->doBatchLookups();
 369                 }
 370
 371                 # Don't use any extra rows returned by the query
 372                 $numRows = min( $this->mResult->numRows(), $this->mLimit );
 373
 374                 $s = $this->getStartBody();
 375                 if ( $numRows ) {
 376                         if ( $this->mIsBackwards ) {
 377                                 for ( $i = $numRows - 1; $i >= 0; $i-- ) {
 378                                         $this->mResult->seek( $i );
 379                                         $row = $this->mResult->fetchObject();
 380                                         $s .= $this->formatRow( $row );
 381                                 }
 382                         } else {
 383                                 $this->mResult->seek( 0 );
 384                                 for ( $i = 0; $i < $numRows; $i++ ) {
 385                                         $row = $this->mResult->fetchObject();
 386                                         $s .= $this->formatRow( $row );
 387                                 }
 388                         }
 389                 } else {
 390                         $s .= $this->getEmptyBody();
 391                 }
 392                 $s .= $this->getEndBody();
 393                 return $s;
 394         }
 395
 396         /**
 397          * Make a self-link
 398          *
 399          * @param $text String: text displayed on the link
 400          * @param $query Array: associative array of paramter to be in the query string
 401          * @param $type String: value of the "rel" attribute
 402          *
 403          * @return String: HTML fragment
 404          */
 405         function makeLink( $text, array $query = null, $type = null ) {
 406                 if ( $query === null ) {
 407                         return $text;
 408                 }
 409
 410                 $attrs = array();
 411                 if( in_array( $type, array( 'first', 'prev', 'next', 'last' ) ) ) {
 412                         # HTML5 rel attributes
 413                         $attrs['rel'] = $type;
 414                 }
 415
 416                 if( $type ) {
 417                         $attrs['class'] = "mw-{$type}link";
 418                 }
 419
 420                 return Linker::linkKnown(
 421                         $this->getTitle(),
 422                         $text,
 423                         $attrs,
 424                         $query + $this->getDefaultQuery()
 425                 );
 426         }
 427
 428         /**
 429          * Called from getBody(), before getStartBody() is called and
 430          * after doQuery() was called. This will be called only if there
 431          * are rows in the result set.
 432          *
 433          * @return void
 434          */
 435         protected function doBatchLookups() {}
 436
 437         /**
 438          * Hook into getBody(), allows text to be inserted at the start. This
 439          * will be called even if there are no rows in the result set.
 440          *
 441          * @return String
 442          */
 443         protected function getStartBody() {
 444                 return '';
 445         }
 446
 447         /**
 448          * Hook into getBody() for the end of the list
 449          *
 450          * @return String
 451          */
 452         protected function getEndBody() {
 453                 return '';
 454         }
 455
 456         /**
 457          * Hook into getBody(), for the bit between the start and the
 458          * end when there are no rows
 459          *
 460          * @return String
 461          */
 462         protected function getEmptyBody() {
 463                 return '';
 464         }
 465
 466         /**
 467          * Get an array of query parameters that should be put into self-links.
 468          * By default, all parameters passed in the URL are used, except for a
 469          * short blacklist.
 470          *
 471          * @return array Associative array
 472          */
 473         function getDefaultQuery() {
 474                 if ( !isset( $this->mDefaultQuery ) ) {
 475                         $this->mDefaultQuery = $this->getRequest()->getQueryValues();
 476                         unset( $this->mDefaultQuery['title'] );
 477                         unset( $this->mDefaultQuery['dir'] );
 478                         unset( $this->mDefaultQuery['offset'] );
 479                         unset( $this->mDefaultQuery['limit'] );
 480                         unset( $this->mDefaultQuery['order'] );
 481                         unset( $this->mDefaultQuery['month'] );
 482                         unset( $this->mDefaultQuery['year'] );
 483                 }
 484                 return $this->mDefaultQuery;
 485         }
 486
 487         /**
 488          * Get the number of rows in the result set
 489          *
 490          * @return Integer
 491          */
 492         function getNumRows() {
 493                 if ( !$this->mQueryDone ) {
 494                         $this->doQuery();
 495                 }
 496                 return $this->mResult->numRows();
 497         }
 498
 499         /**
 500          * Get a URL query array for the prev, next, first and last links.
 501          *
 502          * @return Array
 503          */
 504         function getPagingQueries() {
 505                 if ( !$this->mQueryDone ) {
 506                         $this->doQuery();
 507                 }
 508
 509                 # Don't announce the limit everywhere if it's the default
 510                 $urlLimit = $this->mLimit == $this->mDefaultLimit ? null : $this->mLimit;
 511
 512                 if ( $this->mIsFirst ) {
 513                         $prev = false;
 514                         $first = false;
 515                 } else {
 516                         $prev = array(
 517                                 'dir' => 'prev',
 518                                 'offset' => $this->mFirstShown,
 519                                 'limit' => $urlLimit
 520                         );
 521                         $first = array( 'limit' => $urlLimit );
 522                 }
 523                 if ( $this->mIsLast ) {
 524                         $next = false;
 525                         $last = false;
 526                 } else {
 527                         $next = array( 'offset' => $this->mLastShown, 'limit' => $urlLimit );
 528                         $last = array( 'dir' => 'prev', 'limit' => $urlLimit );
 529                 }
 530                 return array(
 531                         'prev' => $prev,
 532                         'next' => $next,
 533                         'first' => $first,
 534                         'last' => $last
 535                 );
 536         }
 537
 538         /**
 539          * Returns whether to show the "navigation bar"
 540          *
 541          * @return Boolean
 542          */
 543         function isNavigationBarShown() {
 544                 if ( !$this->mQueryDone ) {
 545                         $this->doQuery();
 546                 }
 547                 // Hide navigation by default if there is nothing to page
 548                 return !($this->mIsFirst && $this->mIsLast);
 549         }
 550
 551         /**
 552          * Get paging links. If a link is disabled, the item from $disabledTexts
 553          * will be used. If there is no such item, the unlinked text from
 554          * $linkTexts will be used. Both $linkTexts and $disabledTexts are arrays
 555          * of HTML.
 556          *
 557          * @param $linkTexts Array
 558          * @param $disabledTexts Array
 559          * @return Array
 560          */
 561         function getPagingLinks( $linkTexts, $disabledTexts = array() ) {
 562                 $queries = $this->getPagingQueries();
 563                 $links = array();
 564
 565                 foreach ( $queries as $type => $query ) {
 566                         if ( $query !== false ) {
 567                                 $links[$type] = $this->makeLink(
 568                                         $linkTexts[$type],
 569                                         $queries[$type],
 570                                         $type
 571                                 );
 572                         } elseif ( isset( $disabledTexts[$type] ) ) {
 573                                 $links[$type] = $disabledTexts[$type];
 574                         } else {
 575                                 $links[$type] = $linkTexts[$type];
 576                         }
 577                 }
 578
 579                 return $links;
 580         }
 581
 582         function getLimitLinks() {
 583                 $links = array();
 584                 if ( $this->mIsBackwards ) {
 585                         $offset = $this->mPastTheEndIndex;
 586                 } else {
 587                         $offset = $this->mOffset;
 588                 }
 589                 foreach ( $this->mLimitsShown as $limit ) {
 590                         $links[] = $this->makeLink(
 591                                 $this->getLanguage()->formatNum( $limit ),
 592                                 array( 'offset' => $offset, 'limit' => $limit ),
 593                                 'num'
 594                         );
 595                 }
 596                 return $links;
 597         }
 598
 599         /**
 600          * Abstract formatting function. This should return an HTML string
 601          * representing the result row $row. Rows will be concatenated and
 602          * returned by getBody()
 603          *
 604          * @param $row Object: database row
 605          * @return String
 606          */
 607         abstract function formatRow( $row );
 608
 609         /**
 610          * This function should be overridden to provide all parameters
 611          * needed for the main paged query. It returns an associative
 612          * array with the following elements:
 613          *    tables => Table(s) for passing to Database::select()
 614          *    fields => Field(s) for passing to Database::select(), may be *
 615          *    conds => WHERE conditions
 616          *    options => option array
 617          *    join_conds => JOIN conditions
 618          *
 619          * @return Array
 620          */
 621         abstract function getQueryInfo();
 622
 623         /**
 624          * This function should be overridden to return the name of the index fi-
 625          * eld.  If the pager supports multiple orders, it may return an array of
 626          * 'querykey' => 'indexfield' pairs, so that a request with &count=querykey
 627          * will use indexfield to sort.  In this case, the first returned key is
 628          * the default.
 629          *
 630          * Needless to say, it's really not a good idea to use a non-unique index
 631          * for this!  That won't page right.
 632          *
 633          * @return string|Array
 634          */
 635         abstract function getIndexField();
 636
 637         /**
 638          * This function should be overridden to return the names of secondary columns
 639          * to order by in addition to the column in getIndexField(). These fields will
 640          * not be used in the pager offset or in any links for users.
 641          *
 642          * If getIndexField() returns an array of 'querykey' => 'indexfield' pairs then
 643          * this must return a corresponding array of 'querykey' => array( fields...) pairs
 644          * in order for a request with &count=querykey to use array( fields...) to sort.
 645          *
 646          * This is useful for pagers that GROUP BY a unique column (say page_id)
 647          * and ORDER BY another (say page_len). Using GROUP BY and ORDER BY both on
 648          * page_len,page_id avoids temp tables (given a page_len index). This would
 649          * also work if page_id was non-unique but we had a page_len,page_id index.
 650          *
 651          * @return Array
 652          */
 653         protected function getExtraSortFields() { return array(); }
 654
 655         /**
 656          * Return the default sorting direction: false for ascending, true for de-
 657          * scending.  You can also have an associative array of ordertype => dir,
 658          * if multiple order types are supported.  In this case getIndexField()
 659          * must return an array, and the keys of that must exactly match the keys
 660          * of this.
 661          *
 662          * For backward compatibility, this method's return value will be ignored
 663          * if $this->mDefaultDirection is already set when the constructor is
 664          * called, for instance if it's statically initialized.  In that case the
 665          * value of that variable (which must be a boolean) will be used.
 666          *
 667          * Note that despite its name, this does not return the value of the
 668          * $this->mDefaultDirection member variable.  That's the default for this
 669          * particular instantiation, which is a single value.  This is the set of
 670          * all defaults for the class.
 671          *
 672          * @return Boolean
 673          */
 674         protected function getDefaultDirections() { return false; }
 675 }
 676
 677
 678 /**
 679  * IndexPager with an alphabetic list and a formatted navigation bar
 680  * @ingroup Pager
 681  */
 682 abstract class AlphabeticPager extends IndexPager {
 683
 684         /**
 685          * Shamelessly stolen bits from ReverseChronologicalPager,
 686          * didn't want to do class magic as may be still revamped
 687          *
 688          * @return String HTML
 689          */
 690         function getNavigationBar() {
 691                 if ( !$this->isNavigationBarShown() ) {
 692                         return '';
 693                 }
 694
 695                 if( isset( $this->mNavigationBar ) ) {
 696                         return $this->mNavigationBar;
 697                 }
 698
 699                 $linkTexts = array(
 700                         'prev' => $this->msg( 'prevn' )->numParams( $this->mLimit )->escaped(),
 701                         'next' => $this->msg( 'nextn' )->numParams( $this->mLimit )->escaped(),
 702                         'first' => $this->msg( 'page_first' )->escaped(),
 703                         'last' => $this->msg( 'page_last' )->escaped()
 704                 );
 705
 706                 $lang = $this->getLanguage();
 707
 708                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 709                 $limitLinks = $this->getLimitLinks();
 710                 $limits = $lang->pipeList( $limitLinks );
 711
 712                 $this->mNavigationBar = $this->msg( 'parentheses' )->rawParams(
 713                         $lang->pipeList( array( $pagingLinks['first'],
 714                         $pagingLinks['last'] ) ) )->escaped() . " " .
 715                         $this->msg( 'viewprevnext' )->rawParams( $pagingLinks['prev'],
 716                                 $pagingLinks['next'], $limits )->escaped();
 717
 718                 if( !is_array( $this->getIndexField() ) ) {
 719                         # Early return to avoid undue nesting
 720                         return $this->mNavigationBar;
 721                 }
 722
 723                 $extra = '';
 724                 $first = true;
 725                 $msgs = $this->getOrderTypeMessages();
 726                 foreach( array_keys( $msgs ) as $order ) {
 727                         if( $first ) {
 728                                 $first = false;
 729                         } else {
 730                                 $extra .= $this->msg( 'pipe-separator' )->escaped();
 731                         }
 732
 733                         if( $order == $this->mOrderType ) {
 734                                 $extra .= $this->msg( $msgs[$order] )->escaped();
 735                         } else {
 736                                 $extra .= $this->makeLink(
 737                                         $this->msg( $msgs[$order] )->escaped(),
 738                                         array( 'order' => $order )
 739                                 );
 740                         }
 741                 }
 742
 743                 if( $extra !== '' ) {
 744                         $extra = ' ' . $this->msg( 'parentheses' )->rawParams( $extra )->escaped();
 745                         $this->mNavigationBar .= $extra;
 746                 }
 747
 748                 return $this->mNavigationBar;
 749         }
 750
 751         /**
 752          * If this supports multiple order type messages, give the message key for
 753          * enabling each one in getNavigationBar.  The return type is an associa-
 754          * tive array whose keys must exactly match the keys of the array returned
 755          * by getIndexField(), and whose values are message keys.
 756          *
 757          * @return Array
 758          */
 759         protected function getOrderTypeMessages() {
 760                 return null;
 761         }
 762 }
 763
 764 /**
 765  * IndexPager with a formatted navigation bar
 766  * @ingroup Pager
 767  */
 768 abstract class ReverseChronologicalPager extends IndexPager {
 769         public $mDefaultDirection = true;
 770         public $mYear;
 771         public $mMonth;
 772
 773         function getNavigationBar() {
 774                 if ( !$this->isNavigationBarShown() ) {
 775                         return '';
 776                 }
 777
 778                 if ( isset( $this->mNavigationBar ) ) {
 779                         return $this->mNavigationBar;
 780                 }
 781
 782                 $linkTexts = array(
 783                         'prev' => $this->msg( 'pager-newer-n' )->numParams( $this->mLimit )->escaped(),
 784                         'next' => $this->msg( 'pager-older-n' )->numParams( $this->mLimit )->escaped(),
 785                         'first' => $this->msg( 'histlast' )->escaped(),
 786                         'last' => $this->msg( 'histfirst' )->escaped()
 787                 );
 788
 789                 $pagingLinks = $this->getPagingLinks( $linkTexts );
 790                 $limitLinks = $this->getLimitLinks();
 791                 $limits = $this->getLanguage()->pipeList( $limitLinks );
 792                 $firstLastLinks = $this->msg( 'parentheses' )->rawParams( "{$pagingLinks['first']}" .
 793                         $this->msg( 'pipe-separator' )->escaped() .
 794                         "{$pagingLinks['last']}" )->escaped();
 795
 796                 $this->mNavigationBar = $firstLastLinks . ' ' .
 797                         $this->msg( 'viewprevnext' )->rawParams(
 798                                 $pagingLinks['prev'], $pagingLinks['next'], $limits )->escaped();
 799
 800                 return $this->mNavigationBar;
 801         }
 802
 803         function getDateCond( $year, $month ) {
 804                 $year = intval( $year );
 805                 $month = intval( $month );
 806
 807                 // Basic validity checks
 808                 $this->mYear = $year > 0 ? $year : false;
 809                 $this->mMonth = ( $month > 0 && $month < 13 ) ? $month : false;
 810
 811                 // Given an optional year and month, we need to generate a timestamp
 812                 // to use as "WHERE rev_timestamp <= result"
 813                 // Examples: year = 2006 equals < 20070101 (+000000)
 814                 // year=2005, month=1    equals < 20050201
 815                 // year=2005, month=12   equals < 20060101
 816                 if ( !$this->mYear && !$this->mMonth ) {
 817                         return;
 818                 }
 819
 820                 if ( $this->mYear ) {
 821                         $year = $this->mYear;
 822                 } else {
 823                         // If no year given, assume the current one
 824                         $year = gmdate( 'Y' );
 825                         // If this month hasn't happened yet this year, go back to last year's month
 826                         if( $this->mMonth > gmdate( 'n' ) ) {
 827                                 $year--;
 828                         }
 829                 }
 830
 831                 if ( $this->mMonth ) {
 832                         $month = $this->mMonth + 1;
 833                         // For December, we want January 1 of the next year
 834                         if ($month > 12) {
 835                                 $month = 1;
 836                                 $year++;
 837                         }
 838                 } else {
 839                         // No month implies we want up to the end of the year in question
 840                         $month = 1;
 841                         $year++;
 842                 }
 843
 844                 // Y2K38 bug
 845                 if ( $year > 2032 ) {
 846                         $year = 2032;
 847                 }
 848
 849                 $ymd = (int)sprintf( "%04d%02d01", $year, $month );
 850
 851                 if ( $ymd > 20320101 ) {
 852                         $ymd = 20320101;
 853                 }
 854
 855                 $this->mOffset = $this->mDb->timestamp( "${ymd}000000" );
 856         }
 857 }
 858
 859 /**
 860  * Table-based display with a user-selectable sort order
 861  * @ingroup Pager
 862  */
 863 abstract class TablePager extends IndexPager {
 864         var $mSort;
 865         var $mCurrentRow;
 866
 867         public function __construct( IContextSource $context = null ) {
 868                 if ( $context ) {
 869                         $this->setContext( $context );
 870                 }
 871
 872                 $this->mSort = $this->getRequest()->getText( 'sort' );
 873                 if ( !array_key_exists( $this->mSort, $this->getFieldNames() ) ) {
 874                         $this->mSort = $this->getDefaultSort();
 875                 }
 876                 if ( $this->getRequest()->getBool( 'asc' ) ) {
 877                         $this->mDefaultDirection = false;
 878                 } elseif ( $this->getRequest()->getBool( 'desc' ) ) {
 879                         $this->mDefaultDirection = true;
 880                 } /* Else leave it at whatever the class default is */
 881
 882                 parent::__construct();
 883         }
 884
 885         /**
 886          * @protected
 887          * @return string
 888          */
 889         function getStartBody() {
 890                 global $wgStylePath;
 891                 $tableClass = htmlspecialchars( $this->getTableClass() );
 892                 $sortClass = htmlspecialchars( $this->getSortHeaderClass() );
 893
 894                 $s = "<table style='border:1;' class=\"mw-datatable $tableClass\"><thead><tr>\n";
 895                 $fields = $this->getFieldNames();
 896
 897                 # Make table header
 898                 foreach ( $fields as $field => $name ) {
 899                         if ( strval( $name ) == '' ) {
 900                                 $s .= "<th>&#160;</th>\n";
 901                         } elseif ( $this->isFieldSortable( $field ) ) {
 902                                 $query = array( 'sort' => $field, 'limit' => $this->mLimit );
 903                                 if ( $field == $this->mSort ) {
 904                                         # This is the sorted column
 905                                         # Prepare a link that goes in the other sort order
 906                                         if ( $this->mDefaultDirection ) {
 907                                                 # Descending
 908                                                 $image = 'Arr_d.png';
 909                                                 $query['asc'] = '1';
 910                                                 $query['desc'] = '';
 911                                                 $alt = $this->msg( 'descending_abbrev' )->escaped();
 912                                         } else {
 913                                                 # Ascending
 914                                                 $image = 'Arr_u.png';
 915                                                 $query['asc'] = '';
 916                                                 $query['desc'] = '1';
 917                                                 $alt = $this->msg( 'ascending_abbrev' )->escaped();
 918                                         }
 919                                         $image = htmlspecialchars( "$wgStylePath/common/images/$image" );
 920                                         $link = $this->makeLink(
 921                                                 "<img width=\"12\" height=\"12\" alt=\"$alt\" src=\"$image\" />" .
 922                                                         htmlspecialchars( $name ), $query );
 923                                         $s .= "<th class=\"$sortClass\">$link</th>\n";
 924                                 } else {
 925                                         $s .= '<th>' . $this->makeLink( htmlspecialchars( $name ), $query ) . "</th>\n";
 926                                 }
 927                         } else {
 928                                 $s .= '<th>' . htmlspecialchars( $name ) . "</th>\n";
 929                         }
 930                 }
 931                 $s .= "</tr></thead><tbody>\n";
 932                 return $s;
 933         }
 934
 935         /**
 936          * @protected
 937          * @return string
 938          */
 939         function getEndBody() {
 940                 return "</tbody></table>\n";
 941         }
 942
 943         /**
 944          * @protected
 945          * @return string
 946          */
 947         function getEmptyBody() {
 948                 $colspan = count( $this->getFieldNames() );
 949                 $msgEmpty = $this->msg( 'table_pager_empty' )->escaped();
 950                 return "<tr><td colspan=\"$colspan\">$msgEmpty</td></tr>\n";
 951         }
 952
 953         /**
 954          * @protected
 955          * @param stdClass $row
 956          * @return String HTML
 957          */
 958         function formatRow( $row ) {
 959                 $this->mCurrentRow = $row; // In case formatValue etc need to know
 960                 $s = Xml::openElement( 'tr', $this->getRowAttrs( $row ) );
 961                 $fieldNames = $this->getFieldNames();
 962
 963                 foreach ( $fieldNames as $field => $name ) {
 964                         $value = isset( $row->$field ) ? $row->$field : null;
 965                         $formatted = strval( $this->formatValue( $field, $value ) );
 966
 967                         if ( $formatted == '' ) {
 968                                 $formatted = '&#160;';
 969                         }
 970
 971                         $s .= Xml::tags( 'td', $this->getCellAttrs( $field, $value ), $formatted );
 972                 }
 973
 974                 $s .= "</tr>\n";
 975
 976                 return $s;
 977         }
 978
 979         /**
 980          * Get a class name to be applied to the given row.
 981          *
 982          * @protected
 983          *
 984          * @param $row Object: the database result row
 985          * @return String
 986          */
 987         function getRowClass( $row ) {
 988                 return '';
 989         }
 990
 991         /**
 992          * Get attributes to be applied to the given row.
 993          *
 994          * @protected
 995          *
 996          * @param $row Object: the database result row
 997          * @return Array of <attr> => <value>
 998          */
 999         function getRowAttrs( $row ) {
1000                 $class = $this->getRowClass( $row );
1001                 if ( $class === '' ) {
1002                         // Return an empty array to avoid clutter in HTML like class=""
1003                         return array();
1004                 } else {
1005                         return array( 'class' => $this->getRowClass( $row ) );
1006                 }
1007         }
1008
1009         /**
1010          * Get any extra attributes to be applied to the given cell. Don't
1011          * take this as an excuse to hardcode styles; use classes and
1012          * CSS instead.  Row context is available in $this->mCurrentRow
1013          *
1014          * @protected
1015          *
1016          * @param $field String The column
1017          * @param $value String The cell contents
1018          * @return Array of attr => value
1019          */
1020         function getCellAttrs( $field, $value ) {
1021                 return array( 'class' => 'TablePager_col_' . $field );
1022         }
1023
1024         /**
1025          * @protected
1026          * @return string
1027          */
1028         function getIndexField() {
1029                 return $this->mSort;
1030         }
1031
1032         /**
1033          * @protected
1034          * @return string
1035          */
1036         function getTableClass() {
1037                 return 'TablePager';
1038         }
1039
1040         /**
1041          * @protected
1042          * @return string
1043          */
1044         function getNavClass() {
1045                 return 'TablePager_nav';
1046         }
1047
1048         /**
1049          * @protected
1050          * @return string
1051          */
1052         function getSortHeaderClass() {
1053                 return 'TablePager_sort';
1054         }
1055
1056         /**
1057          * A navigation bar with images
1058          * @return String HTML
1059          */
1060         public function getNavigationBar() {
1061                 global $wgStylePath;
1062
1063                 if ( !$this->isNavigationBarShown() ) {
1064                         return '';
1065                 }
1066
1067                 $path = "$wgStylePath/common/images";
1068                 $labels = array(
1069                         'first' => 'table_pager_first',
1070                         'prev' => 'table_pager_prev',
1071                         'next' => 'table_pager_next',
1072                         'last' => 'table_pager_last',
1073                 );
1074                 $images = array(
1075                         'first' => 'arrow_first_25.png',
1076                         'prev' => 'arrow_left_25.png',
1077                         'next' => 'arrow_right_25.png',
1078                         'last' => 'arrow_last_25.png',
1079                 );
1080                 $disabledImages = array(
1081                         'first' => 'arrow_disabled_first_25.png',
1082                         'prev' => 'arrow_disabled_left_25.png',
1083                         'next' => 'arrow_disabled_right_25.png',
1084                         'last' => 'arrow_disabled_last_25.png',
1085                 );
1086                 if( $this->getLanguage()->isRTL() ) {
1087                         $keys = array_keys( $labels );
1088                         $images = array_combine( $keys, array_reverse( $images ) );
1089                         $disabledImages = array_combine( $keys, array_reverse( $disabledImages ) );
1090                 }
1091
1092                 $linkTexts = array();
1093                 $disabledTexts = array();
1094                 foreach ( $labels as $type => $label ) {
1095                         $msgLabel = $this->msg( $label )->escaped();
1096                         $linkTexts[$type] = "<img src=\"$path/{$images[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
1097                         $disabledTexts[$type] = "<img src=\"$path/{$disabledImages[$type]}\" alt=\"$msgLabel\"/><br />$msgLabel";
1098                 }
1099                 $links = $this->getPagingLinks( $linkTexts, $disabledTexts );
1100
1101                 $navClass = htmlspecialchars( $this->getNavClass() );
1102                 $s = "<table class=\"$navClass\"><tr>\n";
1103                 $width = 100 / count( $links ) . '%';
1104                 foreach ( $labels as $type => $label ) {
1105                         $s .= "<td style='width:$width;'>{$links[$type]}</td>\n";
1106                 }
1107                 $s .= "</tr></table>\n";
1108                 return $s;
1109         }
1110
1111         /**
1112          * Get a <select> element which has options for each of the allowed limits
1113          *
1114          * @return String: HTML fragment
1115          */
1116         public function getLimitSelect() {
1117                 # Add the current limit from the query string
1118                 # to avoid that the limit is lost after clicking Go next time
1119                 if ( !in_array( $this->mLimit, $this->mLimitsShown ) ) {
1120                         $this->mLimitsShown[] = $this->mLimit;
1121                         sort( $this->mLimitsShown );
1122                 }
1123                 $s = Html::openElement( 'select', array( 'name' => 'limit' ) ) . "\n";
1124                 foreach ( $this->mLimitsShown as $key => $value ) {
1125                         # The pair is either $index => $limit, in which case the $value
1126                         # will be numeric, or $limit => $text, in which case the $value
1127                         # will be a string.
1128                         if( is_int( $value ) ){
1129                                 $limit = $value;
1130                                 $text = $this->getLanguage()->formatNum( $limit );
1131                         } else {
1132                                 $limit = $key;
1133                                 $text = $value;
1134                         }
1135                         $s .= Xml::option( $text, $limit, $limit == $this->mLimit ) . "\n";
1136                 }
1137                 $s .= Html::closeElement( 'select' );
1138                 return $s;
1139         }
1140
1141         /**
1142          * Get <input type="hidden"> elements for use in a method="get" form.
1143          * Resubmits all defined elements of the query string, except for a
1144          * blacklist, passed in the $blacklist parameter.
1145          *
1146          * @param $blacklist Array parameters from the request query which should not be resubmitted
1147          * @return String: HTML fragment
1148          */
1149         function getHiddenFields( $blacklist = array() ) {
1150                 $blacklist = (array)$blacklist;
1151                 $query = $this->getRequest()->getQueryValues();
1152                 foreach ( $blacklist as $name ) {
1153                         unset( $query[$name] );
1154                 }
1155                 $s = '';
1156                 foreach ( $query as $name => $value ) {
1157                         $encName = htmlspecialchars( $name );
1158                         $encValue = htmlspecialchars( $value );
1159                         $s .= "<input type=\"hidden\" name=\"$encName\" value=\"$encValue\"/>\n";
1160                 }
1161                 return $s;
1162         }
1163
1164         /**
1165          * Get a form containing a limit selection dropdown
1166          *
1167          * @return String: HTML fragment
1168          */
1169         function getLimitForm() {
1170                 global $wgScript;
1171
1172                 return Xml::openElement(
1173                         'form',
1174                         array(
1175                                 'method' => 'get',
1176                                 'action' => $wgScript
1177                         ) ) . "\n" . $this->getLimitDropdown() . "</form>\n";
1178         }
1179
1180         /**
1181          * Gets a limit selection dropdown
1182          *
1183          * @return string
1184          */
1185         function getLimitDropdown() {
1186                 # Make the select with some explanatory text
1187                 $msgSubmit = $this->msg( 'table_pager_limit_submit' )->escaped();
1188
1189                 return $this->msg( 'table_pager_limit' )
1190                         ->rawParams( $this->getLimitSelect() )->escaped() .
1191                         "\n<input type=\"submit\" value=\"$msgSubmit\"/>\n" .
1192                         $this->getHiddenFields( array( 'limit' ) );
1193         }
1194
1195         /**
1196          * Return true if the named field should be sortable by the UI, false
1197          * otherwise
1198          *
1199          * @param $field String
1200          */
1201         abstract function isFieldSortable( $field );
1202
1203         /**
1204          * Format a table cell. The return value should be HTML, but use an empty
1205          * string not &#160; for empty cells. Do not include the <td> and </td>.
1206          *
1207          * The current result row is available as $this->mCurrentRow, in case you
1208          * need more context.
1209          *
1210          * @protected
1211          *
1212          * @param $name String: the database field name
1213          * @param $value String: the value retrieved from the database
1214          */
1215         abstract function formatValue( $name, $value );
1216
1217         /**
1218          * The database field name used as a default sort order.
1219          *
1220          * @protected
1221          *
1222          * @return string
1223          */
1224         abstract function getDefaultSort();
1225
1226         /**
1227          * An array mapping database field names to a textual description of the
1228          * field name, for use in the table header. The description should be plain
1229          * text, it will be HTML-escaped later.
1230          *
1231          * @return Array
1232          */
1233         abstract function getFieldNames();
1234 }