cms/drupal/includes/pager.inc
changeset 541 e756a8c72c3d
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cms/drupal/includes/pager.inc	Fri Sep 08 12:04:06 2017 +0200
@@ -0,0 +1,664 @@
+<?php
+
+/**
+ * @file
+ * Functions to aid in presenting database results as a set of pages.
+ */
+
+
+/**
+ * Query extender for pager queries.
+ *
+ * This is the "default" pager mechanism.  It creates a paged query with a fixed
+ * number of entries per page.
+ */
+class PagerDefault extends SelectQueryExtender {
+
+  /**
+   * The highest element we've autogenerated so far.
+   *
+   * @var int
+   */
+  static $maxElement = 0;
+
+  /**
+   * The number of elements per page to allow.
+   *
+   * @var int
+   */
+  protected $limit = 10;
+
+  /**
+   * The unique ID of this pager on this page.
+   *
+   * @var int
+   */
+  protected $element = NULL;
+
+  /**
+   * The count query that will be used for this pager.
+   *
+   * @var SelectQueryInterface
+   */
+  protected $customCountQuery = FALSE;
+
+  public function __construct(SelectQueryInterface $query, DatabaseConnection $connection) {
+    parent::__construct($query, $connection);
+
+    // Add pager tag. Do this here to ensure that it is always added before
+    // preExecute() is called.
+    $this->addTag('pager');
+  }
+
+  /**
+   * Override the execute method.
+   *
+   * Before we run the query, we need to add pager-based range() instructions
+   * to it.
+   */
+  public function execute() {
+
+    // Add convenience tag to mark that this is an extended query. We have to
+    // do this in the constructor to ensure that it is set before preExecute()
+    // gets called.
+    if (!$this->preExecute($this)) {
+      return NULL;
+    }
+
+    // A NULL limit is the "kill switch" for pager queries.
+    if (empty($this->limit)) {
+      return;
+    }
+    $this->ensureElement();
+
+    $total_items = $this->getCountQuery()->execute()->fetchField();
+    $current_page = pager_default_initialize($total_items, $this->limit, $this->element);
+    $this->range($current_page * $this->limit, $this->limit);
+
+    // Now that we've added our pager-based range instructions, run the query normally.
+    return $this->query->execute();
+  }
+
+  /**
+   * Ensure that there is an element associated with this query.
+   * If an element was not specified previously, then the value of the
+   * $maxElement counter is taken, after which the counter is incremented.
+   *
+   * After running this method, access $this->element to get the element for this
+   * query.
+   */
+  protected function ensureElement() {
+    if (!isset($this->element)) {
+      $this->element = self::$maxElement++;
+    }
+  }
+
+  /**
+   * Specify the count query object to use for this pager.
+   *
+   * You will rarely need to specify a count query directly.  If not specified,
+   * one is generated off of the pager query itself.
+   *
+   * @param SelectQueryInterface $query
+   *   The count query object.  It must return a single row with a single column,
+   *   which is the total number of records.
+   */
+  public function setCountQuery(SelectQueryInterface $query) {
+    $this->customCountQuery = $query;
+  }
+
+  /**
+   * Retrieve the count query for this pager.
+   *
+   * The count query may be specified manually or, by default, taken from the
+   * query we are extending.
+   *
+   * @return SelectQueryInterface
+   *   A count query object.
+   */
+  public function getCountQuery() {
+    if ($this->customCountQuery) {
+      return $this->customCountQuery;
+    }
+    else {
+      return $this->query->countQuery();
+    }
+  }
+
+  /**
+   * Specify the maximum number of elements per page for this query.
+   *
+   * The default if not specified is 10 items per page.
+   *
+   * @param $limit
+   *   An integer specifying the number of elements per page.  If passed a false
+   *   value (FALSE, 0, NULL), the pager is disabled.
+   */
+  public function limit($limit = 10) {
+    $this->limit = $limit;
+    return $this;
+  }
+
+  /**
+   * Specify the element ID for this pager query.
+   *
+   * The element is used to differentiate different pager queries on the same
+   * page so that they may be operated independently.  If you do not specify an
+   * element, every pager query on the page will get a unique element.  If for
+   * whatever reason you want to explicitly define an element for a given query,
+   * you may do so here.
+   *
+   * Setting the element here also increments the static $maxElement counter,
+   * which is used for determining the $element when there's none specified.
+   *
+   * Note that no collision detection is done when setting an element ID
+   * explicitly, so it is possible for two pagers to end up using the same ID
+   * if both are set explicitly.
+   *
+   * @param $element
+   */
+  public function element($element) {
+    $this->element = $element;
+    if ($element >= self::$maxElement) {
+      self::$maxElement = $element + 1;
+    }
+    return $this;
+  }
+}
+
+/**
+ * Returns the current page being requested for display within a pager.
+ *
+ * @param $element
+ *  An optional integer to distinguish between multiple pagers on one page.
+ *
+ * @return
+ *  The number of the current requested page, within the pager represented by
+ *  $element. This is determined from the URL query parameter $_GET['page'], or
+ *  0 by default. Note that this number may differ from the actual page being
+ *  displayed. For example, if a search for "example text" brings up three
+ *  pages of results, but a users visits search/node/example+text?page=10, this
+ *  function will return 10, even though the default pager implementation
+ *  adjusts for this and still displays the third page of search results at
+ *  that URL.
+ *
+ * @see pager_default_initialize()
+ */
+function pager_find_page($element = 0) {
+  $page = isset($_GET['page']) ? $_GET['page'] : '';
+  $page_array = explode(',', $page);
+  if (!isset($page_array[$element])) {
+    $page_array[$element] = 0;
+  }
+  return (int) $page_array[$element];
+}
+
+/**
+ * Initializes a pager for theme('pager').
+ *
+ * This function sets up the necessary global variables so that future calls
+ * to theme('pager') will render a pager that correctly corresponds to the
+ * items being displayed.
+ *
+ * If the items being displayed result from a database query performed using
+ * Drupal's database API, and if you have control over the construction of the
+ * database query, you do not need to call this function directly; instead, you
+ * can simply extend the query object with the 'PagerDefault' extender before
+ * executing it. For example:
+ * @code
+ *   $query = db_select('some_table')->extend('PagerDefault');
+ * @endcode
+ *
+ * However, if you are using a different method for generating the items to be
+ * paged through, then you should call this function in preparation.
+ *
+ * The following example shows how this function can be used in a page callback
+ * that invokes an external datastore with an SQL-like syntax:
+ * @code
+ *   // First find the total number of items and initialize the pager.
+ *   $where = "status = 1";
+ *   $total = mymodule_select("SELECT COUNT(*) FROM data " . $where)->result();
+ *   $num_per_page = variable_get('mymodule_num_per_page', 10);
+ *   $page = pager_default_initialize($total, $num_per_page);
+ *
+ *   // Next, retrieve and display the items for the current page.
+ *   $offset = $num_per_page * $page;
+ *   $result = mymodule_select("SELECT * FROM data " . $where . " LIMIT %d, %d", $offset, $num_per_page)->fetchAll();
+ *   $output = theme('mymodule_results', array('result' => $result));
+ *
+ *   // Finally, display the pager controls, and return.
+ *   $output .= theme('pager');
+ *   return $output;
+ * @endcode
+ *
+ * A second example involves a page callback that invokes an external search
+ * service where the total number of matching results is provided as part of
+ * the returned set (so that we do not need a separate query in order to obtain
+ * this information). Here, we call pager_find_page() to calculate the desired
+ * offset before the search is invoked:
+ * @code
+ *   // Perform the query, using the requested offset from pager_find_page().
+ *   // This comes from a URL parameter, so here we are assuming that the URL
+ *   // parameter corresponds to an actual page of results that will exist
+ *   // within the set.
+ *   $page = pager_find_page();
+ *   $num_per_page = variable_get('mymodule_num_per_page', 10);
+ *   $offset = $num_per_page * $page;
+ *   $result = mymodule_remote_search($keywords, $offset, $num_per_page);
+ *
+ *   // Now that we have the total number of results, initialize the pager.
+ *   pager_default_initialize($result->total, $num_per_page);
+ *
+ *   // Display the search results.
+ *   $output = theme('search_results', array('results' => $result->data, 'type' => 'remote'));
+ *
+ *   // Finally, display the pager controls, and return.
+ *   $output .= theme('pager');
+ *   return $output;
+ * @endcode
+ *
+ * @param $total
+ *  The total number of items to be paged.
+ * @param $limit
+ *  The number of items the calling code will display per page.
+ * @param $element
+ *  An optional integer to distinguish between multiple pagers on one page.
+ *
+ * @return
+ *   The number of the current page, within the pager represented by $element.
+ *   This is determined from the URL query parameter $_GET['page'], or 0 by
+ *   default. However, if a page that does not correspond to the actual range
+ *   of the result set was requested, this function will return the closest
+ *   page actually within the result set.
+ */
+function pager_default_initialize($total, $limit, $element = 0) {
+  global $pager_page_array, $pager_total, $pager_total_items, $pager_limits;
+
+  $page = pager_find_page($element);
+
+  // We calculate the total of pages as ceil(items / limit).
+  $pager_total_items[$element] = $total;
+  $pager_total[$element] = ceil($pager_total_items[$element] / $limit);
+  $pager_page_array[$element] = max(0, min($page, ((int) $pager_total[$element]) - 1));
+  $pager_limits[$element] = $limit;
+  return $pager_page_array[$element];
+}
+
+/**
+ * Compose a URL query parameter array for pager links.
+ *
+ * @return
+ *   A URL query parameter array that consists of all components of the current
+ *   page request except for those pertaining to paging.
+ */
+function pager_get_query_parameters() {
+  $query = &drupal_static(__FUNCTION__);
+  if (!isset($query)) {
+    $query = drupal_get_query_parameters($_GET, array('q', 'page'));
+  }
+  return $query;
+}
+
+/**
+ * Returns HTML for 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 $variables
+ *   An associative array containing:
+ *   - tags: An array of labels for the controls in the pager.
+ *   - element: An optional integer to distinguish between multiple pagers on
+ *     one page.
+ *   - parameters: An associative array of query string parameters to append to
+ *     the pager links.
+ *   - quantity: The number of pages in the list.
+ *
+ * @ingroup themeable
+ */
+function theme_pager($variables) {
+  $tags = $variables['tags'];
+  $element = $variables['element'];
+  $parameters = $variables['parameters'];
+  $quantity = $variables['quantity'];
+  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.
+
+  $li_first = theme('pager_first', array('text' => (isset($tags[0]) ? $tags[0] : t('« first')), 'element' => $element, 'parameters' => $parameters));
+  $li_previous = theme('pager_previous', array('text' => (isset($tags[1]) ? $tags[1] : t('‹ previous')), 'element' => $element, 'interval' => 1, 'parameters' => $parameters));
+  $li_next = theme('pager_next', array('text' => (isset($tags[3]) ? $tags[3] : t('next ›')), 'element' => $element, 'interval' => 1, 'parameters' => $parameters));
+  $li_last = theme('pager_last', array('text' => (isset($tags[4]) ? $tags[4] : t('last »')), 'element' => $element, 'parameters' => $parameters));
+
+  if ($pager_total[$element] > 1) {
+    if ($li_first) {
+      $items[] = array(
+        'class' => array('pager-first'),
+        'data' => $li_first,
+      );
+    }
+    if ($li_previous) {
+      $items[] = array(
+        'class' => array('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' => array('pager-ellipsis'),
+          'data' => '…',
+        );
+      }
+      // Now generate the actual pager piece.
+      for (; $i <= $pager_last && $i <= $pager_max; $i++) {
+        if ($i < $pager_current) {
+          $items[] = array(
+            'class' => array('pager-item'),
+            'data' => theme('pager_previous', array('text' => $i, 'element' => $element, 'interval' => ($pager_current - $i), 'parameters' => $parameters)),
+          );
+        }
+        if ($i == $pager_current) {
+          $items[] = array(
+            'class' => array('pager-current'),
+            'data' => $i,
+          );
+        }
+        if ($i > $pager_current) {
+          $items[] = array(
+            'class' => array('pager-item'),
+            'data' => theme('pager_next', array('text' => $i, 'element' => $element, 'interval' => ($i - $pager_current), 'parameters' => $parameters)),
+          );
+        }
+      }
+      if ($i < $pager_max) {
+        $items[] = array(
+          'class' => array('pager-ellipsis'),
+          'data' => '…',
+        );
+      }
+    }
+    // End generation.
+    if ($li_next) {
+      $items[] = array(
+        'class' => array('pager-next'),
+        'data' => $li_next,
+      );
+    }
+    if ($li_last) {
+      $items[] = array(
+        'class' => array('pager-last'),
+        'data' => $li_last,
+      );
+    }
+    return '<h2 class="element-invisible">' . t('Pages') . '</h2>' . theme('item_list', array(
+      'items' => $items,
+      'attributes' => array('class' => array('pager')),
+    ));
+  }
+}
+
+
+/**
+ * @defgroup pagerpieces Pager pieces
+ * @{
+ * Theme functions for customizing pager elements.
+ *
+ * Note that you should NOT modify this file to customize your pager.
+ */
+
+/**
+ * Returns HTML for the "first page" link in a query pager.
+ *
+ * @param $variables
+ *   An associative array containing:
+ *   - text: The name (or image) of the link.
+ *   - element: An optional integer to distinguish between multiple pagers on
+ *     one page.
+ *   - parameters: An associative array of query string parameters to append to
+ *     the pager links.
+ *
+ * @ingroup themeable
+ */
+function theme_pager_first($variables) {
+  $text = $variables['text'];
+  $element = $variables['element'];
+  $parameters = $variables['parameters'];
+  global $pager_page_array;
+  $output = '';
+
+  // If we are anywhere but the first page
+  if ($pager_page_array[$element] > 0) {
+    $output = theme('pager_link', array('text' => $text, 'page_new' => pager_load_array(0, $element, $pager_page_array), 'element' => $element, 'parameters' => $parameters));
+  }
+
+  return $output;
+}
+
+/**
+ * Returns HTML for the "previous page" link in a query pager.
+ *
+ * @param $variables
+ *   An associative array containing:
+ *   - text: The name (or image) of the link.
+ *   - element: An optional integer to distinguish between multiple pagers on
+ *     one page.
+ *   - interval: The number of pages to move backward when the link is clicked.
+ *   - parameters: An associative array of query string parameters to append to
+ *     the pager links.
+ *
+ * @ingroup themeable
+ */
+function theme_pager_previous($variables) {
+  $text = $variables['text'];
+  $element = $variables['element'];
+  $interval = $variables['interval'];
+  $parameters = $variables['parameters'];
+  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', array('text' => $text, 'element' => $element, 'parameters' => $parameters));
+    }
+    // The previous page is not the first page.
+    else {
+      $output = theme('pager_link', array('text' => $text, 'page_new' => $page_new, 'element' => $element, 'parameters' => $parameters));
+    }
+  }
+
+  return $output;
+}
+
+/**
+ * Returns HTML for the "next page" link in a query pager.
+ *
+ * @param $variables
+ *   An associative array containing:
+ *   - text: The name (or image) of the link.
+ *   - element: An optional integer to distinguish between multiple pagers on
+ *     one page.
+ *   - interval: The number of pages to move forward when the link is clicked.
+ *   - parameters: An associative array of query string parameters to append to
+ *     the pager links.
+ *
+ * @ingroup themeable
+ */
+function theme_pager_next($variables) {
+  $text = $variables['text'];
+  $element = $variables['element'];
+  $interval = $variables['interval'];
+  $parameters = $variables['parameters'];
+  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', array('text' => $text, 'element' => $element, 'parameters' => $parameters));
+    }
+    // The next page is not the last page.
+    else {
+      $output = theme('pager_link', array('text' => $text, 'page_new' => $page_new, 'element' => $element, 'parameters' => $parameters));
+    }
+  }
+
+  return $output;
+}
+
+/**
+ * Returns HTML for the "last page" link in query pager.
+ *
+ * @param $variables
+ *   An associative array containing:
+ *   - text: The name (or image) of the link.
+ *   - element: An optional integer to distinguish between multiple pagers on
+ *     one page.
+ *   - parameters: An associative array of query string parameters to append to
+ *     the pager links.
+ *
+ * @ingroup themeable
+ */
+function theme_pager_last($variables) {
+  $text = $variables['text'];
+  $element = $variables['element'];
+  $parameters = $variables['parameters'];
+  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', array('text' => $text, 'page_new' => pager_load_array($pager_total[$element] - 1, $element, $pager_page_array), 'element' => $element, 'parameters' => $parameters));
+  }
+
+  return $output;
+}
+
+
+/**
+ * Returns HTML for a link to a specific query result page.
+ *
+ * @param $variables
+ *   An associative array containing:
+ *   - text: The link text. Also used to figure out the title attribute of the
+ *     link, if it is not provided in $variables['attributes']['title']; in
+ *     this case, $variables['text'] must be one of the standard pager link
+ *     text strings that would be generated by the pager theme functions, such
+ *     as a number or t('« first').
+ *   - page_new: The first result to display on the linked page.
+ *   - element: An optional integer to distinguish between multiple pagers on
+ *     one page.
+ *   - parameters: An associative array of query string parameters to append to
+ *     the pager link.
+ *   - attributes: An associative array of HTML attributes to apply to the
+ *     pager link.
+ *
+ * @see theme_pager()
+ *
+ * @ingroup themeable
+ */
+function theme_pager_link($variables) {
+  $text = $variables['text'];
+  $page_new = $variables['page_new'];
+  $element = $variables['element'];
+  $parameters = $variables['parameters'];
+  $attributes = $variables['attributes'];
+
+  $page = isset($_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)) {
+    $query = drupal_get_query_parameters($parameters, array());
+  }
+  if ($query_pager = pager_get_query_parameters()) {
+    $query = array_merge($query, $query_pager);
+  }
+
+  // Set each pager link title
+  if (!isset($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];
+    }
+    elseif (is_numeric($text)) {
+      $attributes['title'] = t('Go to page @number', array('@number' => $text));
+    }
+  }
+
+  // @todo l() cannot be used here, since it adds an 'active' class based on the
+  //   path only (which is always the current path for pager links). Apparently,
+  //   none of the pager links is active at any time - but it should still be
+  //   possible to use l() here.
+  // @see http://drupal.org/node/1410574
+  $attributes['href'] = url($_GET['q'], array('query' => $query));
+  return '<a' . drupal_attributes($attributes) . '>' . check_plain($text) . '</a>';
+}
+
+/**
+ * @} 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; $i++) {
+    if (empty($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;
+}