class views_plugin_cache in Views (for Drupal 7) 6.2

The base plugin to handle caching.

Hierarchy

• class \views_object
  • class \views_plugin
    • class \views_plugin_cache

1 string reference to 'views_plugin_cache'

views_views_plugins in includes/plugins.inc

Implementation of hook_views_plugins

File

plugins/views_plugin_cache.inc, line 8

class views_plugin_cache extends views_plugin {

  /**
   * Contains all data that should be written/read from cache.
   */
  var $storage = array();

  /**
   * What table to store data in.
   */
  var $table = 'cache_views_data';

  /**
   * Initialize the plugin.
   *
   * @param $view
   *   The view object.
   * @param $display
   *   The display handler.
   */
  function init(&$view, &$display) {
    $this->view =& $view;
    $this->display =& $display;
    $this->options = array();
    if (is_object($display->handler)) {

      // Note: The below is read only.
      $this->options = $display->handler
        ->get_option('cache');
    }
  }

  /**
   * Retrieve the default options when this is a new access
   * control plugin
   */
  function option_defaults(&$options) {
  }

  /**
   * Return a string to display as the clickable title for the
   * access control.
   */
  function summary_title() {
    return t('Unknown');
  }

  /**
   * Determine the expiration time of the cache type, or NULL if no expire.
   *
   * Plugins must override this to implement expiration.
   *
   * @param $type
   *   The cache type, either 'query', 'result' or 'output'.
   */
  function cache_expire($type) {
  }

  /**
   * Determine expiration time in the cache table of the cache type
   * or CACHE_PERMANENT if item shouldn't be removed automatically from cache.
   *
   * Plugins must override this to implement expiration in the cache table.
   *
   * @param $type
   *   The cache type, either 'query', 'result' or 'output'.
   */
  function cache_set_expire($type) {
    return CACHE_PERMANENT;
  }

  /**
   * Save data to the cache.
   *
   * A plugin should override this to provide specialized caching behavior.
   */
  function cache_set($type) {
    switch ($type) {
      case 'query':

        // Not supported currently, but this is certainly where we'd put it.
        break;
      case 'results':
        $data = array(
          'result' => $this->view->result,
          'total_rows' => $this->view->total_rows,
          'pager' => $this->view->pager,
        );
        cache_set($this
          ->get_results_key(), $data, $this->table, $this
          ->cache_set_expire($type));
        break;
      case 'output':
        $this
          ->gather_headers();
        $this->storage['output'] = $this->view->display_handler->output;
        cache_set($this
          ->get_output_key(), $this->storage, $this->table, $this
          ->cache_set_expire($type));
        break;
    }
  }

  /**
   * Retrieve data from the cache.
   *
   * A plugin should override this to provide specialized caching behavior.
   */
  function cache_get($type) {
    $cutoff = $this
      ->cache_expire($type);
    switch ($type) {
      case 'query':

        // Not supported currently, but this is certainly where we'd put it.
        return FALSE;
      case 'results':

        // Values to set: $view->result, $view->total_rows, $view->execute_time,
        // $view->pager['current_page'].
        if ($cache = cache_get($this
          ->get_results_key(), $this->table)) {
          if (!$cutoff || $cache->created > $cutoff) {
            $this->view->result = $cache->data['result'];
            $this->view->total_rows = $cache->data['total_rows'];
            $this->view->pager = $cache->data['pager'];
            $this->view->execute_time = 0;
            return TRUE;
          }
        }
        return FALSE;
      case 'output':
        if ($cache = cache_get($this
          ->get_output_key(), $this->table)) {
          if (!$cutoff || $cache->created > $cutoff) {
            $this->storage = $cache->data;
            $this->view->display_handler->output = $cache->data['output'];
            $this
              ->restore_headers();
            return TRUE;
          }
        }
        return FALSE;
    }
  }

  /**
   * Clear out cached data for a view.
   *
   * We're just going to nuke anything related to the view, regardless of display,
   * to be sure that we catch everything. Maybe that's a bad idea.
   */
  function cache_flush() {
    cache_clear_all($this->view->name . ':', $this->table, TRUE);
  }

  /**
   * Post process any rendered data.
   *
   * This can be valuable to be able to cache a view and still have some level of
   * dynamic output. In an ideal world, the actual output will include HTML
   * comment based tokens, and then the post process can replace those tokens.
   *
   * Example usage. If it is known that the view is a node view and that the
   * primary field will be a nid, you can do something like this:
   *
   * <!--post-FIELD-NID-->
   *
   * And then in the post render, create an array with the text that should
   * go there:
   *
   * strtr($output, array('<!--post-FIELD-1-->', 'output for FIELD of nid 1');
   *
   * All of the cached result data will be available in $view->result, as well,
   * so all ids used in the query should be discoverable.
   */
  function post_render(&$output) {
  }

  /**
   * Start caching javascript, css and other out of band info.
   *
   * This takes a snapshot of the current system state so that we don't
   * duplicate it. Later on, when gather_headers() is run, this information
   * will be removed so that we don't hold onto it.
   */
  function cache_start() {
    $this->storage['head'] = drupal_set_html_head();
    $this->storage['css'] = drupal_add_css();
    foreach (array(
      'header',
      'footer',
    ) as $scope) {
      $this->storage['js'][$scope] = drupal_add_js(NULL, NULL, $scope);
    }
  }

  /**
   * Gather out of band data, compare it to what we started with and store the difference.
   */
  function gather_headers() {

    // Simple replacement for head
    $this->storage['head'] = str_replace($this->storage['head'], '', drupal_set_html_head());

    // Slightly less simple for CSS:
    $css = drupal_add_css();
    $start = $this->storage['css'];
    $this->storage['css'] = array();
    foreach ($css as $media => $medias) {
      foreach ($medias as $type => $types) {
        foreach ($types as $path => $preprocess) {
          if (!isset($start[$media][$type][$path])) {
            $this->storage['css'][] = array(
              $path,
              $type,
              $media,
              $preprocess,
            );
          }
        }
      }
    }
    $js = array();

    // A little less simple for js
    foreach (array(
      'header',
      'footer',
    ) as $scope) {
      $js[$scope] = drupal_add_js(NULL, NULL, $scope);
    }
    $start = $this->storage['js'];
    $this->storage['js'] = array();
    foreach ($js as $scope => $scopes) {
      foreach ($scopes as $type => $types) {
        foreach ($types as $id => $info) {
          if (!isset($start[$scope][$type][$id])) {
            switch ($type) {
              case 'setting':
                $this->storage['js'][] = array(
                  $info,
                  $type,
                  $scope,
                );
                break;
              case 'inline':
                $this->storage['js'][] = array(
                  $info['code'],
                  $type,
                  $scope,
                  $info['defer'],
                );
                break;
              default:
                $this->storage['js'][] = array(
                  $id,
                  $type,
                  $scope,
                  $info['defer'],
                  $info['cache'],
                );
            }
          }
        }
      }
    }
  }

  /**
   * Restore out of band data saved to cache. Copied from Panels.
   */
  function restore_headers() {
    if (!empty($this->storage['head'])) {
      drupal_set_html_head($this->storage['head']);
    }
    if (!empty($this->storage['css'])) {
      foreach ($this->storage['css'] as $args) {
        call_user_func_array('drupal_add_css', $args);
      }
    }
    if (!empty($this->storage['js'])) {
      foreach ($this->storage['js'] as $args) {
        call_user_func_array('drupal_add_js', $args);
      }
    }
  }
  function get_results_key() {
    global $user;
    if (!isset($this->_results_key)) {
      $key_data = array(
        'build_info' => $this->view->build_info,
        'roles' => array_keys($user->roles),
        'super-user' => $user->uid == 1,
        // special caching for super user.
        'language' => $GLOBALS['language'],
      );
      foreach (array(
        'exposed_info',
        'page',
        'sort',
        'order',
      ) as $key) {
        if (isset($_GET[$key])) {
          $key_data[$key] = $_GET[$key];
        }
      }
      $this->_results_key = $this->view->name . ':' . $this->display->id . ':results:' . md5(serialize($key_data));
    }
    return $this->_results_key;
  }
  function get_output_key() {
    global $user;
    if (!isset($this->_output_key)) {
      $key_data = array(
        'result' => $this->view->result,
        'roles' => array_keys($user->roles),
        'super-user' => $user->uid == 1,
        // special caching for super user.
        'theme' => $GLOBALS['theme'],
        'language' => $GLOBALS['language'],
      );
      $this->_output_key = $this->view->name . ':' . $this->display->id . ':output:' . md5(serialize($key_data));
    }
    return $this->_output_key;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
views_object::$options		property	Except for displays, options for the object will be held here.	1
views_object::construct		function	Views handlers use a special construct function so that we can more easily construct them with variable arguments.	5
views_object::destroy		function		2
views_object::options		function	Set default options on this object. Called by the constructor in a complex chain to deal with backward compatibility.	1
views_object::option_definition		function	Information about options for all kinds of purposes will be held here.	9
views_object::set_default_options		function	Set default options. For backward compatibility, it sends the options array; this is a feature that will likely disappear at some point.
views_object::set_definition		function	Let the handler know what its full definition is.
views_object::unpack_options		function	Unpack options over our existing defaults, drilling down into arrays so that defaults don't get totally blown away.
views_object::_set_option_defaults		function		1
views_plugin::additional_theme_functions		function	Provide a list of additional theme functions for the theme information page
views_plugin::options_form		function	Provide a form to edit options for this plugin.	5
views_plugin::options_submit		function	Handle any special handling on the validate form.	3
views_plugin::options_validate		function	Validate the options form.	3
views_plugin::query		function	Add anything to the query that we might need to.	3
views_plugin::theme_functions		function	Provide a full list of possible theme templates used by this style.
views_plugin::validate		function	Validate that the plugin is correct and can be saved.	2
views_plugin_cache::$storage		property	Contains all data that should be written/read from cache.
views_plugin_cache::$table		property	What table to store data in.
views_plugin_cache::cache_expire		function	Determine the expiration time of the cache type, or NULL if no expire.	1
views_plugin_cache::cache_flush		function	Clear out cached data for a view.
views_plugin_cache::cache_get		function	Retrieve data from the cache.	1
views_plugin_cache::cache_set		function	Save data to the cache.	1
views_plugin_cache::cache_set_expire		function	Determine expiration time in the cache table of the cache type or CACHE_PERMANENT if item shouldn't be removed automatically from cache.	1
views_plugin_cache::cache_start		function	Start caching javascript, css and other out of band info.	1
views_plugin_cache::gather_headers		function	Gather out of band data, compare it to what we started with and store the difference.
views_plugin_cache::get_output_key		function
views_plugin_cache::get_results_key		function
views_plugin_cache::init		function	Initialize the plugin. Overrides views_plugin::init
views_plugin_cache::option_defaults		function	Retrieve the default options when this is a new access control plugin	1
views_plugin_cache::post_render		function	Post process any rendered data.
views_plugin_cache::restore_headers		function	Restore out of band data saved to cache. Copied from Panels.
views_plugin_cache::summary_title		function	Return a string to display as the clickable title for the access control.	2