[Summary view] [Print] [Text view]

   1  <?php
   2  // $Id: pager.inc,v 1.63.2.1 2009/07/01 20:51:55 goba Exp $
   3  
   4  /**
   5   * @file
   6   * Functions to aid in presenting database results as a set of pages.
   7   */
   8  
   9  /**
  10   * Perform a paged database query.
  11   *
  12   * Use this function when doing select queries you wish to be able to page. The
  13   * pager uses LIMIT-based queries to fetch only the records required to render a
  14   * certain page. However, it has to learn the total number of records returned
  15   * by the query to compute the number of pages (the number of records / records
  16   * per page). This is done by inserting "COUNT(*)" in the original query. For
  17   * example, the query "SELECT nid, type FROM node WHERE status = '1' ORDER BY
  18   * sticky DESC, created DESC" would be rewritten to read "SELECT COUNT(*) FROM
  19   * node WHERE status = '1' ORDER BY sticky DESC, created DESC". Rewriting the
  20   * query is accomplished using a regular expression.
  21   *
  22   * Unfortunately, the rewrite rule does not always work as intended for queries
  23   * that already have a "COUNT(*)" or a "GROUP BY" clause, and possibly for
  24   * other complex queries. In those cases, you can optionally pass a query that
  25   * will be used to count the records.
  26   *
  27   * For example, if you want to page the query "SELECT COUNT(*), TYPE FROM node
  28   * GROUP BY TYPE", pager_query() would invoke the incorrect query "SELECT
  29   * COUNT(*) FROM node GROUP BY TYPE". So instead, you should pass "SELECT
  30   * COUNT(DISTINCT(TYPE)) FROM node" as the optional $count_query parameter.
  31   *
  32   * @param $query
  33   *   The SQL query that needs paging.
  34   * @param $limit
  35   *   The number of query results to display per page.
  36   * @param $element
  37   *   An optional integer to distinguish between multiple pagers on one page.
  38   * @param $count_query
  39   *   An SQL query used to count matching records.
  40   * @param ...
  41   *   A variable number of arguments which are substituted into the query (and
  42   *   the count query) using printf() syntax. Instead of a variable number of
  43   *   query arguments, you may also pass a single array containing the query
  44   *   arguments.
  45   * @return
  46   *   A database query result resource, or FALSE if the query was not executed
  47   *   correctly.
  48   *
  49   * @ingroup database
  50   */
  51  function pager_query($query, $limit = 10, $element = 0, $count_query = NULL) {
  52    global $pager_page_array, $pager_total, $pager_total_items;
  53    $page = isset($_GET['page']) ? $_GET['page'] : '';
  54  
  55    // Substitute in query arguments.
  56    $args = func_get_args();
  57    $args = array_slice($args, 4);
  58    // Alternative syntax for '...'
  59    if (isset($args[0]) && is_array($args[0])) {
  60      $args = $args[0];
  61    }
  62  
  63    // Construct a count query if none was given.
  64    if (!isset($count_query)) {
  65      $count_query = preg_replace(array('/SELECT.*?FROM /As', '/ORDER BY .*/'), array('SELECT COUNT(*) FROM ', ''), $query);
  66    }
  67  
  68    // Convert comma-separated $page to an array, used by other functions.
  69    $pager_page_array = explode(',', $page);
  70  
  71    // We calculate the total of pages as ceil(items / limit).
  72    $pager_total_items[$element] = db_result(db_query($count_query, $args));
  73    $pager_total[$element] = ceil($pager_total_items[$element] / $limit);
  74    $pager_page_array[$element] = max(0, min((int)$pager_page_array[$element], ((int)$pager_total[$element]) - 1));
  75    return db_query_range($query, $args, $pager_page_array[$element] * $limit, $limit);
  76  }
  77  
  78  /**
  79   * Compose a query string to append to pager requests.
  80   *
  81   * @return
  82   *   A query string that consists of all components of the current page request
  83   *   except for those pertaining to paging.
  84   */
  85  function pager_get_querystring() {
  86    static $string = NULL;
  87    if (!isset($string)) {
  88      $string = drupal_query_string_encode($_REQUEST, array_merge(array('q', 'page', 'pass'), array_keys($_COOKIE)));
  89    }
  90    return $string;
  91  }
  92  
  93  /**
  94   * Format a query pager.
  95   *
  96   * Menu callbacks that display paged query results should call theme('pager') to
  97   * retrieve a pager control so that users can view other results.
  98   * Format a list of nearby pages with additional query results.
  99   *
 100   * @param $tags
 101   *   An array of labels for the controls in the pager.
 102   * @param $limit
 103   *   The number of query results to display per page.
 104   * @param $element
 105   *   An optional integer to distinguish between multiple pagers on one page.
 106   * @param $parameters
 107   *   An associative array of query string parameters to append to the pager links.
 108   * @param $quantity
 109   *   The number of pages in the list.
 110   * @return
 111   *   An HTML string that generates the query pager.
 112   *
 113   * @ingroup themeable
 114   */
 115  function theme_pager($tags = array(), $limit = 10, $element = 0, $parameters = array(), $quantity = 9) {
 116    global $pager_page_array, $pager_total;
 117  
 118    // Calculate various markers within this pager piece:
 119    // Middle is used to "center" pages around the current page.
 120    $pager_middle = ceil($quantity / 2);
 121    // current is the page we are currently paged to
 122    $pager_current = $pager_page_array[$element] + 1;
 123    // first is the first page listed by this pager piece (re quantity)
 124    $pager_first = $pager_current - $pager_middle + 1;
 125    // last is the last page listed by this pager piece (re quantity)
 126    $pager_last = $pager_current + $quantity - $pager_middle;
 127    // max is the maximum page number
 128    $pager_max = $pager_total[$element];
 129    // End of marker calculations.
 130  
 131    // Prepare for generation loop.
 132    $i = $pager_first;
 133    if ($pager_last > $pager_max) {
 134      // Adjust "center" if at end of query.
 135      $i = $i + ($pager_max - $pager_last);
 136      $pager_last = $pager_max;
 137    }
 138    if ($i <= 0) {
 139      // Adjust "center" if at start of query.
 140      $pager_last = $pager_last + (1 - $i);
 141      $i = 1;
 142    }
 143    // End of generation loop preparation.
 144  
 145    $li_first = theme('pager_first', (isset($tags[0]) ? $tags[0] : t('« first')), $limit, $element, $parameters);
 146    $li_previous = theme('pager_previous', (isset($tags[1]) ? $tags[1] : t('‹ previous')), $limit, $element, 1, $parameters);
 147    $li_next = theme('pager_next', (isset($tags[3]) ? $tags[3] : t('next ›')), $limit, $element, 1, $parameters);
 148    $li_last = theme('pager_last', (isset($tags[4]) ? $tags[4] : t('last »')), $limit, $element, $parameters);
 149  
 150    if ($pager_total[$element] > 1) {
 151      if ($li_first) {
 152        $items[] = array(
 153          'class' => 'pager-first',
 154          'data' => $li_first,
 155        );
 156      }
 157      if ($li_previous) {
 158        $items[] = array(
 159          'class' => 'pager-previous',
 160          'data' => $li_previous,
 161        );
 162      }
 163  
 164      // When there is more than one page, create the pager list.
 165      if ($i != $pager_max) {
 166        if ($i > 1) {
 167          $items[] = array(
 168            'class' => 'pager-ellipsis',
 169            'data' => '…',
 170          );
 171        }
 172        // Now generate the actual pager piece.
 173        for (; $i <= $pager_last && $i <= $pager_max; $i++) {
 174          if ($i < $pager_current) {
 175            $items[] = array(
 176              'class' => 'pager-item',
 177              'data' => theme('pager_previous', $i, $limit, $element, ($pager_current - $i), $parameters),
 178            );
 179          }
 180          if ($i == $pager_current) {
 181            $items[] = array(
 182              'class' => 'pager-current',
 183              'data' => $i,
 184            );
 185          }
 186          if ($i > $pager_current) {
 187            $items[] = array(
 188              'class' => 'pager-item',
 189              'data' => theme('pager_next', $i, $limit, $element, ($i - $pager_current), $parameters),
 190            );
 191          }
 192        }
 193        if ($i < $pager_max) {
 194          $items[] = array(
 195            'class' => 'pager-ellipsis',
 196            'data' => '…',
 197          );
 198        }
 199      }
 200      // End generation.
 201      if ($li_next) {
 202        $items[] = array(
 203          'class' => 'pager-next',
 204          'data' => $li_next,
 205        );
 206      }
 207      if ($li_last) {
 208        $items[] = array(
 209          'class' => 'pager-last',
 210          'data' => $li_last,
 211        );
 212      }
 213      return theme('item_list', $items, NULL, 'ul', array('class' => 'pager'));
 214    }
 215  }
 216  
 217  
 218  /**
 219   * @name Pager pieces
 220   * @{
 221   * Use these pieces to construct your own custom pagers in your theme. Note that
 222   * you should NOT modify this file to customize your pager.
 223   */
 224  
 225  /**
 226   * Format a "first page" link.
 227   *
 228   * @param $text
 229   *   The name (or image) of the link.
 230   * @param $limit
 231   *   The number of query results to display per page.
 232   * @param $element
 233   *   An optional integer to distinguish between multiple pagers on one page.
 234   * @param $parameters
 235   *   An associative array of query string parameters to append to the pager links.
 236   * @return
 237   *   An HTML string that generates this piece of the query pager.
 238   *
 239   * @ingroup themeable
 240   */
 241  function theme_pager_first($text, $limit, $element = 0, $parameters = array()) {
 242    global $pager_page_array;
 243    $output = '';
 244  
 245    // If we are anywhere but the first page
 246    if ($pager_page_array[$element] > 0) {
 247      $output = theme('pager_link', $text, pager_load_array(0, $element, $pager_page_array), $element, $parameters);
 248    }
 249  
 250    return $output;
 251  }
 252  
 253  /**
 254   * Format a "previous page" link.
 255   *
 256   * @param $text
 257   *   The name (or image) of the link.
 258   * @param $limit
 259   *   The number of query results to display per page.
 260   * @param $element
 261   *   An optional integer to distinguish between multiple pagers on one page.
 262   * @param $interval
 263   *   The number of pages to move backward when the link is clicked.
 264   * @param $parameters
 265   *   An associative array of query string parameters to append to the pager links.
 266   * @return
 267   *   An HTML string that generates this piece of the query pager.
 268   *
 269   * @ingroup themeable
 270   */
 271  function theme_pager_previous($text, $limit, $element = 0, $interval = 1, $parameters = array()) {
 272    global $pager_page_array;
 273    $output = '';
 274  
 275    // If we are anywhere but the first page
 276    if ($pager_page_array[$element] > 0) {
 277      $page_new = pager_load_array($pager_page_array[$element] - $interval, $element, $pager_page_array);
 278  
 279      // If the previous page is the first page, mark the link as such.
 280      if ($page_new[$element] == 0) {
 281        $output = theme('pager_first', $text, $limit, $element, $parameters);
 282      }
 283      // The previous page is not the first page.
 284      else {
 285        $output = theme('pager_link', $text, $page_new, $element, $parameters);
 286      }
 287    }
 288  
 289    return $output;
 290  }
 291  
 292  /**
 293   * Format a "next page" link.
 294   *
 295   * @param $text
 296   *   The name (or image) of the link.
 297   * @param $limit
 298   *   The number of query results to display per page.
 299   * @param $element
 300   *   An optional integer to distinguish between multiple pagers on one page.
 301   * @param $interval
 302   *   The number of pages to move forward when the link is clicked.
 303   * @param $parameters
 304   *   An associative array of query string parameters to append to the pager links.
 305   * @return
 306   *   An HTML string that generates this piece of the query pager.
 307   *
 308   * @ingroup themeable
 309   */
 310  function theme_pager_next($text, $limit, $element = 0, $interval = 1, $parameters = array()) {
 311    global $pager_page_array, $pager_total;
 312    $output = '';
 313  
 314    // If we are anywhere but the last page
 315    if ($pager_page_array[$element] < ($pager_total[$element] - 1)) {
 316      $page_new = pager_load_array($pager_page_array[$element] + $interval, $element, $pager_page_array);
 317      // If the next page is the last page, mark the link as such.
 318      if ($page_new[$element] == ($pager_total[$element] - 1)) {
 319        $output = theme('pager_last', $text, $limit, $element, $parameters);
 320      }
 321      // The next page is not the last page.
 322      else {
 323        $output = theme('pager_link', $text, $page_new, $element, $parameters);
 324      }
 325    }
 326  
 327    return $output;
 328  }
 329  
 330  /**
 331   * Format a "last page" link.
 332   *
 333   * @param $text
 334   *   The name (or image) of the link.
 335   * @param $limit
 336   *   The number of query results to display per page.
 337   * @param $element
 338   *   An optional integer to distinguish between multiple pagers on one page.
 339   * @param $parameters
 340   *   An associative array of query string parameters to append to the pager links.
 341   * @return
 342   *   An HTML string that generates this piece of the query pager.
 343   *
 344   * @ingroup themeable
 345   */
 346  function theme_pager_last($text, $limit, $element = 0, $parameters = array()) {
 347    global $pager_page_array, $pager_total;
 348    $output = '';
 349  
 350    // If we are anywhere but the last page
 351    if ($pager_page_array[$element] < ($pager_total[$element] - 1)) {
 352      $output = theme('pager_link', $text, pager_load_array($pager_total[$element] - 1, $element, $pager_page_array), $element, $parameters);
 353    }
 354  
 355    return $output;
 356  }
 357  
 358  
 359  /**
 360   * Format a link to a specific query result page.
 361   *
 362   * @param $page_new
 363   *   The first result to display on the linked page.
 364   * @param $element
 365   *   An optional integer to distinguish between multiple pagers on one page.
 366   * @param $parameters
 367   *   An associative array of query string parameters to append to the pager link.
 368   * @param $attributes
 369   *   An associative array of HTML attributes to apply to a pager anchor tag.
 370   * @return
 371   *   An HTML string that generates the link.
 372   *
 373   * @ingroup themeable
 374   */
 375  function theme_pager_link($text, $page_new, $element, $parameters = array(), $attributes = array()) {
 376    $page = isset($_GET['page']) ? $_GET['page'] : '';
 377    if ($new_page = implode(',', pager_load_array($page_new[$element], $element, explode(',', $page)))) {
 378      $parameters['page'] = $new_page;
 379    }
 380  
 381    $query = array();
 382    if (count($parameters)) {
 383      $query[] = drupal_query_string_encode($parameters, array());
 384    }
 385    $querystring = pager_get_querystring();
 386    if ($querystring != '') {
 387      $query[] = $querystring;
 388    }
 389  
 390    // Set each pager link title
 391    if (!isset($attributes['title'])) {
 392      static $titles = NULL;
 393      if (!isset($titles)) {
 394        $titles = array(
 395          t('« first') => t('Go to first page'),
 396          t('‹ previous') => t('Go to previous page'),
 397          t('next ›') => t('Go to next page'),
 398          t('last »') => t('Go to last page'),
 399        );
 400      }
 401      if (isset($titles[$text])) {
 402        $attributes['title'] = $titles[$text];
 403      }
 404      else if (is_numeric($text)) {
 405        $attributes['title'] = t('Go to page @number', array('@number' => $text));
 406      }
 407    }
 408  
 409    return l($text, $_GET['q'], array('attributes' => $attributes, 'query' => count($query) ? implode('&', $query) : NULL));
 410  }
 411  
 412  /**
 413   * @} End of "Pager pieces".
 414   */
 415  
 416  /**
 417   * Helper function
 418   *
 419   * Copies $old_array to $new_array and sets $new_array[$element] = $value
 420   * Fills in $new_array[0 .. $element - 1] = 0
 421   */
 422  function pager_load_array($value, $element, $old_array) {
 423    $new_array = $old_array;
 424    // Look for empty elements.
 425    for ($i = 0; $i < $element; $i++) {
 426      if (!$new_array[$i]) {
 427        // Load found empty element with 0.
 428        $new_array[$i] = 0;
 429      }
 430    }
 431    // Update the changed element.
 432    $new_array[$element] = (int)$value;
 433    return $new_array;
 434  }