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<?php
/**
* @file
* Functions to aid in presenting database results as a set of pages.
*/
/**
* Perform a paged database query.
*
* Use this function when doing select queries you wish to be able to page. The
* pager uses LIMIT-based queries to fetch only the records required to render a
* certain page. However, it has to learn the total number of records returned
* by the query to compute the number of pages (the number of records / records
* per page). This is done by inserting "COUNT(*)" in the original query. For
* example, the query "SELECT nid, type FROM node WHERE status = '1' ORDER BY
* sticky DESC, created DESC" would be rewritten to read "SELECT COUNT(*) FROM
* node WHERE status = '1' ORDER BY sticky DESC, created DESC". Rewriting the
* query is accomplished using a regular expression.
*
* Unfortunately, the rewrite rule does not always work as intended for queries
* that already have a "COUNT(*)" or a "GROUP BY" clause, and possibly for
* other complex queries. In those cases, you can optionally pass a query that
* will be used to count the records.
*
* For example, if you want to page the query "SELECT COUNT(*), TYPE FROM node
* GROUP BY TYPE", pager_query() would invoke the incorrect query "SELECT
* COUNT(*) FROM node GROUP BY TYPE". So instead, you should pass "SELECT
* COUNT(DISTINCT(TYPE)) FROM node" as the optional $count_query parameter.
*
* @param $query
* The SQL query that needs paging.
* @param $limit
* The number of query results to display per page.
* @param $element
* An optional integer to distinguish between multiple pagers on one page.
* @param $count_query
* An SQL query used to count matching records.
* @param ...
* A variable number of arguments which are substituted into the query (and
* the count query) using printf() syntax. Instead of a variable number of
* query arguments, you may also pass a single array containing the query
* arguments.
* @return
* A database query result resource, or FALSE if the query was not executed
* correctly.
*
* @ingroup database
*/
function pager_query($query, $limit = 10, $element = 0, $count_query = NULL) {
global $pager_page_array, $pager_total, $pager_total_items;
$page = isset($_GET['page']) ? $_GET['page'] : '';
// Substitute in query arguments.
$args = func_get_args();
$args = array_slice($args, 4);
// Alternative syntax for '...'
if (isset($args[0]) && is_array($args[0])) {
$args = $args[0];
}
// Construct a count query if none was given.
if (!isset($count_query)) {
$count_query = preg_replace(array('/SELECT.*?FROM /As', '/ORDER BY .*/'), array('SELECT COUNT(*) FROM ', ''), $query);
}
// Convert comma-separated $page to an array, used by other functions.
$pager_page_array = explode(',', $page);
// We calculate the total of pages as ceil(items / limit).
$pager_total_items[$element] = db_result(db_query($count_query, $args));
$pager_total[$element] = ceil($pager_total_items[$element] / $limit);
$pager_page_array[$element] = max(0, min((int)$pager_page_array[$element], ((int)$pager_total[$element]) - 1));
return db_query_range($query, $args, $pager_page_array[$element] * $limit, $limit);
}
/**
* Compose a query string to append to pager requests.
*
* @return
* A query string that consists of all components of the current page request
* except for those pertaining to paging.
*/
function pager_get_querystring() {
static $string = NULL;
if (!isset($string)) {
$string = drupal_query_string_encode($_REQUEST, array_merge(array('q', 'page', 'pass'), array_keys($_COOKIE)));
}
return $string;
}
/**
* Format a query pager.
*
* Menu callbacks that display paged query results should call theme('pager') to
* retrieve a pager control so that users can view other results.
* Format a list of nearby pages with additional query results.
*
* @param $tags
* An array of labels for the controls in the pager.
* @param $limit
* The number of query results to display per page.
* @param $element
* An optional integer to distinguish between multiple pagers on one page.
* @param $parameters
* An associative array of query string parameters to append to the pager links.
* @param $quantity
* The number of pages in the list.
* @return
* An HTML string that generates the query pager.
*
* @ingroup themeable
*/
function theme_pager($tags = array(), $limit = 10, $element = 0, $parameters = array(), $quantity = 9) {
global $pager_page_array, $pager_total;
// Calculate various markers within this pager piece:
// Middle is used to "center" pages around the current page.
$pager_middle = ceil($quantity / 2);
// current is the page we are currently paged to
$pager_current = $pager_page_array[$element] + 1;
// first is the first page listed by this pager piece (re quantity)
$pager_first = $pager_current - $pager_middle + 1;
// last is the last page listed by this pager piece (re quantity)
$pager_last = $pager_current + $quantity - $pager_middle;
// max is the maximum page number
$pager_max = $pager_total[$element];
// End of marker calculations.
// Prepare for generation loop.
$i = $pager_first;
if ($pager_last > $pager_max) {
// Adjust "center" if at end of query.
$i = $i + ($pager_max - $pager_last);
$pager_last = $pager_max;
}
if ($i <= 0) {
// Adjust "center" if at start of query.
$pager_last = $pager_last + (1 - $i);
$i = 1;
}
// End of generation loop preparation.
$li_first = theme('pager_first', (isset($tags[0]) ? $tags[0] : t('« first')), $limit, $element, $parameters);
$li_previous = theme('pager_previous', (isset($tags[1]) ? $tags[1] : t('‹ previous')), $limit, $element, 1, $parameters);
$li_next = theme('pager_next', (isset($tags[3]) ? $tags[3] : t('next ›')), $limit, $element, 1, $parameters);
$li_last = theme('pager_last', (isset($tags[4]) ? $tags[4] : t('last »')), $limit, $element, $parameters);
if ($pager_total[$element] > 1) {
if ($li_first) {
$items[] = array(
'class' => 'pager-first',
'data' => $li_first,
);
}
if ($li_previous) {
$items[] = array(
'class' => 'pager-previous',
'data' => $li_previous,
);
}
// When there is more than one page, create the pager list.
if ($i != $pager_max) {
if ($i > 1) {
$items[] = array(
'class' => 'pager-ellipsis',
'data' => '',
);
}
// Now generate the actual pager piece.
for (; $i <= $pager_last && $i <= $pager_max; $i++) {
if ($i < $pager_current) {
$items[] = array(
'class' => 'pager-item',
'data' => theme('pager_previous', $i, $limit, $element, ($pager_current - $i), $parameters),
);
}
if ($i == $pager_current) {
$items[] = array(
'class' => 'pager-current',
'data' => $i,
);
}
if ($i > $pager_current) {
$items[] = array(
'class' => 'pager-item',
'data' => theme('pager_next', $i, $limit, $element, ($i - $pager_current), $parameters),
);
}
}
if ($i < $pager_max) {
$items[] = array(
'class' => 'pager-ellipsis',
'data' => '',
);
}
}
// End generation.
if ($li_next) {
$items[] = array(
'class' => 'pager-next',
'data' => $li_next,
);
}
if ($li_last) {
$items[] = array(
'class' => 'pager-last',
'data' => $li_last,
);
}
return theme('item_list', $items, NULL, 'ul', array('class' => 'pager'));
}
}
/**
* @defgroup pagerpieces Pager pieces
* @{
* Theme functions for customizing pager elements.
*
* Note that you should NOT modify this file to customize your pager.
*/
/**
* Format a "first page" link.
*
* @param $text
* The name (or image) of the link.
* @param $limit
* The number of query results to display per page.
* @param $element
* An optional integer to distinguish between multiple pagers on one page.
* @param $parameters
* An associative array of query string parameters to append to the pager links.
* @return
* An HTML string that generates this piece of the query pager.
*
* @ingroup themeable
*/
function theme_pager_first($text, $limit, $element = 0, $parameters = array()) {
global $pager_page_array;
$output = '';
// If we are anywhere but the first page
if ($pager_page_array[$element] > 0) {
$output = theme('pager_link', $text, pager_load_array(0, $element, $pager_page_array), $element, $parameters);
}
return $output;
}
/**
* Format a "previous page" link.
*
* @param $text
* The name (or image) of the link.
* @param $limit
* The number of query results to display per page.
* @param $element
* An optional integer to distinguish between multiple pagers on one page.
* @param $interval
* The number of pages to move backward when the link is clicked.
* @param $parameters
* An associative array of query string parameters to append to the pager links.
* @return
* An HTML string that generates this piece of the query pager.
*
* @ingroup themeable
*/
function theme_pager_previous($text, $limit, $element = 0, $interval = 1, $parameters = array()) {
global $pager_page_array;
$output = '';
// If we are anywhere but the first page
if ($pager_page_array[$element] > 0) {
$page_new = pager_load_array($pager_page_array[$element] - $interval, $element, $pager_page_array);
// If the previous page is the first page, mark the link as such.
if ($page_new[$element] == 0) {
$output = theme('pager_first', $text, $limit, $element, $parameters);
}
// The previous page is not the first page.
else {
$output = theme('pager_link', $text, $page_new, $element, $parameters);
}
}
return $output;
}
/**
* Format a "next page" link.
*
* @param $text
* The name (or image) of the link.
* @param $limit
* The number of query results to display per page.
* @param $element
* An optional integer to distinguish between multiple pagers on one page.
* @param $interval
* The number of pages to move forward when the link is clicked.
* @param $parameters
* An associative array of query string parameters to append to the pager links.
* @return
* An HTML string that generates this piece of the query pager.
*
* @ingroup themeable
*/
function theme_pager_next($text, $limit, $element = 0, $interval = 1, $parameters = array()) {
global $pager_page_array, $pager_total;
$output = '';
// If we are anywhere but the last page
if ($pager_page_array[$element] < ($pager_total[$element] - 1)) {
$page_new = pager_load_array($pager_page_array[$element] + $interval, $element, $pager_page_array);
// If the next page is the last page, mark the link as such.
if ($page_new[$element] == ($pager_total[$element] - 1)) {
$output = theme('pager_last', $text, $limit, $element, $parameters);
}
// The next page is not the last page.
else {
$output = theme('pager_link', $text, $page_new, $element, $parameters);
}
}
return $output;
}
/**
* Format a "last page" link.
*
* @param $text
* The name (or image) of the link.
* @param $limit
* The number of query results to display per page.
* @param $element
* An optional integer to distinguish between multiple pagers on one page.
* @param $parameters
* An associative array of query string parameters to append to the pager links.
* @return
* An HTML string that generates this piece of the query pager.
*
* @ingroup themeable
*/
function theme_pager_last($text, $limit, $element = 0, $parameters = array()) {
global $pager_page_array, $pager_total;
$output = '';
// If we are anywhere but the last page
if ($pager_page_array[$element] < ($pager_total[$element] - 1)) {
$output = theme('pager_link', $text, pager_load_array($pager_total[$element] - 1, $element, $pager_page_array), $element, $parameters);
}
return $output;
}
/**
* Format a link to a specific query result page.
*
* @param $page_new
* The first result to display on the linked page.
* @param $element
* An optional integer to distinguish between multiple pagers on one page.
* @param $parameters
* An associative array of query string parameters to append to the pager link.
* @param $attributes
* An associative array of HTML attributes to apply to a pager anchor tag.
* @return
* An HTML string that generates the link.
*
* @ingroup themeable
*/
function theme_pager_link($text, $page_new, $element, $parameters = array(), $attributes = array()) {
$page = isset($_GET['page']) ? $_GET['page'] : '';
if ($new_page = implode(',', pager_load_array($page_new[$element], $element, explode(',', $page)))) {
$parameters['page'] = $new_page;
}
$query = array();
if (count($parameters)) {
$query[] = drupal_query_string_encode($parameters, array());
}
$querystring = pager_get_querystring();
if ($querystring != '') {
$query[] = $querystring;
}
// Set each pager link title
if (!isset($attributes['title'])) {
static $titles = NULL;
if (!isset($titles)) {
$titles = array(
t('« first') => t('Go to first page'),
t('‹ previous') => t('Go to previous page'),
t('next ›') => t('Go to next page'),
t('last »') => t('Go to last page'),
);
}
if (isset($titles[$text])) {
$attributes['title'] = $titles[$text];
}
else if (is_numeric($text)) {
$attributes['title'] = t('Go to page @number', array('@number' => $text));
}
}
return l($text, $_GET['q'], array('attributes' => $attributes, 'query' => count($query) ? implode('&', $query) : NULL));
}
/**
* @} End of "Pager pieces".
*/
/**
* Helper function
*
* Copies $old_array to $new_array and sets $new_array[$element] = $value
* Fills in $new_array[0 .. $element - 1] = 0
*/
function pager_load_array($value, $element, $old_array) {
$new_array = $old_array;
// Look for empty elements.
for ($i = 0; $i < $element; $i++) {
if (!$new_array[$i]) {
// Load found empty element with 0.
$new_array[$i] = 0;
}
}
// Update the changed element.
$new_array[$element] = (int)$value;
return $new_array;
}