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   1  <?php
   2  
   3  /**
   4   * @file
   5   * Functions to aid in presenting database results as a set of pages.
   6   */
   7  
   8  /**
   9   * Perform a paged database query.
  10   *
  11   * Use this function when doing select queries you wish to be able to page. The
  12   * pager uses LIMIT-based queries to fetch only the records required to render a
  13   * certain page. However, it has to learn the total number of records returned
  14   * by the query to compute the number of pages (the number of records / records
  15   * per page). This is done by inserting "COUNT(*)" in the original query. For
  16   * example, the query "SELECT nid, type FROM node WHERE status = '1' ORDER BY
  17   * sticky DESC, created DESC" would be rewritten to read "SELECT COUNT(*) FROM
  18   * node WHERE status = '1' ORDER BY sticky DESC, created DESC". Rewriting the
  19   * query is accomplished using a regular expression.
  20   *
  21   * Unfortunately, the rewrite rule does not always work as intended for queries
  22   * that already have a "COUNT(*)" or a "GROUP BY" clause, and possibly for
  23   * other complex queries. In those cases, you can optionally pass a query that
  24   * will be used to count the records.
  25   *
  26   * For example, if you want to page the query "SELECT COUNT(*), TYPE FROM node
  27   * GROUP BY TYPE", pager_query() would invoke the incorrect query "SELECT
  28   * COUNT(*) FROM node GROUP BY TYPE". So instead, you should pass "SELECT
  29   * COUNT(DISTINCT(TYPE)) FROM node" as the optional $count_query parameter.
  30   *
  31   * @param $query
  32   *   The SQL query that needs paging.
  33   * @param $limit
  34   *   The number of query results to display per page.
  35   * @param $element
  36   *   An optional integer to distinguish between multiple pagers on one page.
  37   * @param $count_query
  38   *   An SQL query used to count matching records.
  39   * @param ...
  40   *   A variable number of arguments which are substituted into the query (and
  41   *   the count query) using printf() syntax. Instead of a variable number of
  42   *   query arguments, you may also pass a single array containing the query
  43   *   arguments.
  44   * @return
  45   *   A database query result resource, or FALSE if the query was not executed
  46   *   correctly.
  47   *
  48   * @ingroup database
  49   */
  50  function pager_query($query, $limit = 10, $element = 0, $count_query = NULL) {
  51    global $pager_page_array, $pager_total, $pager_total_items;
  52    $page = isset($_GET['page']) ? $_GET['page'] : '';
  53  
  54    // Substitute in query arguments.
  55    $args = func_get_args();
  56    $args = array_slice($args, 4);
  57    // Alternative syntax for '...'
  58    if (isset($args[0]) && is_array($args[0])) {
  59      $args = $args[0];
  60    }
  61  
  62    // Construct a count query if none was given.
  63    if (!isset($count_query)) {
  64      $count_query = preg_replace(array('/SELECT.*?FROM /As', '/ORDER BY .*/'), array('SELECT COUNT(*) FROM ', ''), $query);
  65    }
  66  
  67    // Convert comma-separated $page to an array, used by other functions.
  68    $pager_page_array = explode(',', $page);
  69  
  70    // We calculate the total of pages as ceil(items / limit).
  71    $pager_total_items[$element] = db_result(db_query($count_query, $args));
  72    $pager_total[$element] = ceil($pager_total_items[$element] / $limit);
  73    $pager_page_array[$element] = max(0, min((int)$pager_page_array[$element], ((int)$pager_total[$element]) - 1));
  74    return db_query_range($query, $args, $pager_page_array[$element] * $limit, $limit);
  75  }
  76  
  77  /**
  78   * Compose a query string to append to pager requests.
  79   *
  80   * @return
  81   *   A query string that consists of all components of the current page request
  82   *   except for those pertaining to paging.
  83   */
  84  function pager_get_querystring() {
  85    static $string = NULL;
  86    if (!isset($string)) {
  87      $string = drupal_query_string_encode($_REQUEST, array_merge(array('q', 'page', 'pass'), array_keys($_COOKIE)));
  88    }
  89    return $string;
  90  }
  91  
  92  /**
  93   * Returns HTML for a query pager.
  94   *
  95   * Menu callbacks that display paged query results should call theme('pager') to
  96   * retrieve a pager control so that users can view other results.
  97   * Format a list of nearby pages with additional query results.
  98   *
  99   * @param $tags
 100   *   An array of labels for the controls in the pager.
 101   * @param $limit
 102   *   The number of query results to display per page.
 103   * @param $element
 104   *   An optional integer to distinguish between multiple pagers on one page.
 105   * @param $parameters
 106   *   An associative array of query string parameters to append to the pager links.
 107   * @param $quantity
 108   *   The number of pages in the list.
 109   * @return
 110   *   An HTML string that generates the query pager.
 111   *
 112   * @ingroup themeable
 113   */
 114  function theme_pager($tags = array(), $limit = 10, $element = 0, $parameters = array(), $quantity = 9) {
 115    global $pager_page_array, $pager_total;
 116  
 117    // Calculate various markers within this pager piece:
 118    // Middle is used to "center" pages around the current page.
 119    $pager_middle = ceil($quantity / 2);
 120    // current is the page we are currently paged to
 121    $pager_current = $pager_page_array[$element] + 1;
 122    // first is the first page listed by this pager piece (re quantity)
 123    $pager_first = $pager_current - $pager_middle + 1;
 124    // last is the last page listed by this pager piece (re quantity)
 125    $pager_last = $pager_current + $quantity - $pager_middle;
 126    // max is the maximum page number
 127    $pager_max = $pager_total[$element];
 128    // End of marker calculations.
 129  
 130    // Prepare for generation loop.
 131    $i = $pager_first;
 132    if ($pager_last > $pager_max) {
 133      // Adjust "center" if at end of query.
 134      $i = $i + ($pager_max - $pager_last);
 135      $pager_last = $pager_max;
 136    }
 137    if ($i <= 0) {
 138      // Adjust "center" if at start of query.
 139      $pager_last = $pager_last + (1 - $i);
 140      $i = 1;
 141    }
 142    // End of generation loop preparation.
 143  
 144    $li_first = theme('pager_first', (isset($tags[0]) ? $tags[0] : t('« first')), $limit, $element, $parameters);
 145    $li_previous = theme('pager_previous', (isset($tags[1]) ? $tags[1] : t('‹ previous')), $limit, $element, 1, $parameters);
 146    $li_next = theme('pager_next', (isset($tags[3]) ? $tags[3] : t('next ›')), $limit, $element, 1, $parameters);
 147    $li_last = theme('pager_last', (isset($tags[4]) ? $tags[4] : t('last »')), $limit, $element, $parameters);
 148  
 149    if ($pager_total[$element] > 1) {
 150      if ($li_first) {
 151        $items[] = array(
 152          'class' => 'pager-first',
 153          'data' => $li_first,
 154        );
 155      }
 156      if ($li_previous) {
 157        $items[] = array(
 158          'class' => 'pager-previous',
 159          'data' => $li_previous,
 160        );
 161      }
 162  
 163      // When there is more than one page, create the pager list.
 164      if ($i != $pager_max) {
 165        if ($i > 1) {
 166          $items[] = array(
 167            'class' => 'pager-ellipsis',
 168            'data' => '…',
 169          );
 170        }
 171        // Now generate the actual pager piece.
 172        for (; $i <= $pager_last && $i <= $pager_max; $i++) {
 173          if ($i < $pager_current) {
 174            $items[] = array(
 175              'class' => 'pager-item',
 176              'data' => theme('pager_previous', $i, $limit, $element, ($pager_current - $i), $parameters),
 177            );
 178          }
 179          if ($i == $pager_current) {
 180            $items[] = array(
 181              'class' => 'pager-current',
 182              'data' => $i,
 183            );
 184          }
 185          if ($i > $pager_current) {
 186            $items[] = array(
 187              'class' => 'pager-item',
 188              'data' => theme('pager_next', $i, $limit, $element, ($i - $pager_current), $parameters),
 189            );
 190          }
 191        }
 192        if ($i < $pager_max) {
 193          $items[] = array(
 194            'class' => 'pager-ellipsis',
 195            'data' => '…',
 196          );
 197        }
 198      }
 199      // End generation.
 200      if ($li_next) {
 201        $items[] = array(
 202          'class' => 'pager-next',
 203          'data' => $li_next,
 204        );
 205      }
 206      if ($li_last) {
 207        $items[] = array(
 208          'class' => 'pager-last',
 209          'data' => $li_last,
 210        );
 211      }
 212      return theme('item_list', $items, NULL, 'ul', array('class' => 'pager'));
 213    }
 214  }
 215  
 216  
 217  /**
 218   * @defgroup pagerpieces Pager pieces
 219   * @{
 220   * Theme functions for customizing pager elements.
 221   *
 222   * Note that you should NOT modify this file to customize your pager.
 223   */
 224  
 225  /**
 226   * Returns HTML for 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   * Returns HTML for 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   * Returns HTML for 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   * Returns HTML for 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   * Returns HTML for a link to a specific query result page.
 361   *
 362   * @param $text
 363   *   The link text. Also used to figure out the title attribute of the link,
 364   *   if it is not provided in $attributes['title']; in this case, $text must
 365   *   be one of the standard pager link text strings that would be generated by
 366   *   the pager theme functions, such as a number or t('« first').
 367   * @param $page_new
 368   *   The first result to display on the linked page.
 369   * @param $element
 370   *   An optional integer to distinguish between multiple pagers on one page.
 371   * @param $parameters
 372   *   An associative array of query string parameters to append to the pager link.
 373   * @param $attributes
 374   *   An associative array of HTML attributes to apply to the pager link.
 375   * @return
 376   *   An HTML string that generates the link.
 377   *
 378   * @ingroup themeable
 379   */
 380  function theme_pager_link($text, $page_new, $element, $parameters = array(), $attributes = array()) {
 381    $page = isset($_GET['page']) ? $_GET['page'] : '';
 382    if ($new_page = implode(',', pager_load_array($page_new[$element], $element, explode(',', $page)))) {
 383      $parameters['page'] = $new_page;
 384    }
 385  
 386    $query = array();
 387    if (count($parameters)) {
 388      $query[] = drupal_query_string_encode($parameters, array());
 389    }
 390    $querystring = pager_get_querystring();
 391    if ($querystring != '') {
 392      $query[] = $querystring;
 393    }
 394  
 395    // Set each pager link title
 396    if (!isset($attributes['title'])) {
 397      static $titles = NULL;
 398      if (!isset($titles)) {
 399        $titles = array(
 400          t('« first') => t('Go to first page'),
 401          t('‹ previous') => t('Go to previous page'),
 402          t('next ›') => t('Go to next page'),
 403          t('last »') => t('Go to last page'),
 404        );
 405      }
 406      if (isset($titles[$text])) {
 407        $attributes['title'] = $titles[$text];
 408      }
 409      else if (is_numeric($text)) {
 410        $attributes['title'] = t('Go to page @number', array('@number' => $text));
 411      }
 412    }
 413  
 414    return l($text, $_GET['q'], array('attributes' => $attributes, 'query' => count($query) ? implode('&', $query) : NULL));
 415  }
 416  
 417  /**
 418   * @} End of "Pager pieces".
 419   */
 420  
 421  /**
 422   * Helper function
 423   *
 424   * Copies $old_array to $new_array and sets $new_array[$element] = $value
 425   * Fills in $new_array[0 .. $element - 1] = 0
 426   */
 427  function pager_load_array($value, $element, $old_array) {
 428    $new_array = $old_array;
 429    // Look for empty elements.
 430    for ($i = 0; $i < $element; $i++) {
 431      if (!$new_array[$i]) {
 432        // Load found empty element with 0.
 433        $new_array[$i] = 0;
 434      }
 435    }
 436    // Update the changed element.
 437    $new_array[$element] = (int)$value;
 438    return $new_array;
 439  }