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 }