source: sipes/modules_contrib/ctools/ctools.module

<?php

/**
 * @file
 * CTools primary module file.
 *
 * Most of the CTools tools are in their own .inc files. This contains
 * nothing more than a few convenience functions and some hooks that
 * must be implemented in the module file.
 */

define('CTOOLS_API_VERSION', '1.9');

/**
 * Test the CTools API version.
 *
 * This function can always be used to safely test if CTools has the minimum
 * API version that your module can use. It can also try to protect you from
 * running if the CTools API version is too new, but if you do that you need
 * to be very quick about watching CTools API releases and release new versions
 * of your software as soon as the new release is made, or people might end up
 * updating CTools and having your module shut down without any recourse.
 *
 * It is recommended that every hook of your module that might use CTools or
 * might lead to a use of CTools be guarded like this:
 *
 * @code
 * if (!module_invoke('ctools', 'api_version', '1.0')) {
 *   return;
 * }
 * @endcode
 *
 * Note that some hooks such as _menu() or _theme() must return an array().
 *
 * You can use it in your hook_requirements to report this error condition
 * like this:
 *
 * @code
 * define('MODULENAME_MINIMUM_CTOOLS_API_VERSION', '1.0');
 * define('MODULENAME_MAXIMUM_CTOOLS_API_VERSION', '1.1');
 *
 * function MODULENAME_requirements($phase) {
 *   $requirements = array();
 *   if (!module_invoke('ctools', 'api_version', MODULENAME_MINIMUM_CTOOLS_API_VERSION, MODULENAME_MAXIMUM_CTOOLS_API_VERSION)) {
 *      $requirements['MODULENAME_ctools'] = array(
 *        'title' => $t('MODULENAME required Chaos Tool Suite (CTools) API Version'),
 *        'value' => t('Between @a and @b', array('@a' => MODULENAME_MINIMUM_CTOOLS_API_VERSION, '@b' => MODULENAME_MAXIMUM_CTOOLS_API_VERSION)),
 *        'severity' => REQUIREMENT_ERROR,
 *      );
 *   }
 *   return $requirements;
 * }
 * @endcode
 *
 * Please note that the version is a string, not an floating point number.
 * This will matter once CTools reaches version 1.10.
 *
 * A CTools API changes history will be kept in API.txt. Not every new
 * version of CTools will necessarily update the API version.
 * @param $minimum
 *   The minimum version of CTools necessary for your software to run with it.
 * @param $maximum
 *   The maximum version of CTools allowed for your software to run with it.
 */
function ctools_api_version($minimum, $maximum = NULL) {
  if (version_compare(CTOOLS_API_VERSION, $minimum, '<')) {
    return FALSE;
  }

  if (isset($maximum) && version_compare(CTOOLS_API_VERSION, $maximum, '>')) {
    return FALSE;
  }

  return TRUE;
}

// -----------------------------------------------------------------------
// General utility functions

/**
 * Include .inc files as necessary.
 *
 * This fuction is helpful for including .inc files for your module. The
 * general case is including ctools funcitonality like this:
 *
 * @code
 * ctools_include('plugins');
 * @endcode
 *
 * Similar funcitonality can be used for other modules by providing the $module
 * and $dir arguments like this:
 *
 * @code
 * // include mymodule/includes/import.inc
 * ctools_include('import', 'mymodule');
 * // include mymodule/plugins/foobar.inc
 * ctools_include('foobar', 'mymodule', 'plugins');
 * @endcode
 *
 * @param $file
 *   The base file name to be included.
 * @param $module
 *   Optional module containing the include.
 * @param $dir
 *   Optional subdirectory containing the include file.
 */
function ctools_include($file, $module = 'ctools', $dir = 'includes') {
  static $used = array();

  $dir = '/' . ($dir ? $dir . '/' : '');

  if (!isset($used[$module][$dir][$file])) {
    require_once './' . drupal_get_path('module', $module) . "$dir$file.inc";
    $used[$module][$dir][$file] = true;
  }
}

/**
 * Provide the proper path to an image as necessary.
 *
 * This helper function is used by ctools but can also be used in other
 * modules in the same way as explained in the comments of ctools_include.
 *
 * @param $image
 *   The base file name (with extension)  of the image to be included.
 * @param $module
 *   Optional module containing the include.
 * @param $dir
 *   Optional subdirectory containing the include file.
 */
function ctools_image_path($image, $module = 'ctools', $dir = 'images') {
  return drupal_get_path('module', $module) . "/$dir/" . $image;
}

/**
 * Include css files as necessary.
 *
 * This helper function is used by ctools but can also be used in other
 * modules in the same way as explained in the comments of ctools_include.
 *
 * @param $file
 *   The base file name to be included.
 * @param $module
 *   Optional module containing the include.
 * @param $dir
 *   Optional subdirectory containing the include file.
 */
function ctools_add_css($file, $module = 'ctools', $dir = 'css') {
  drupal_add_css(drupal_get_path('module', $module) . "/$dir/$file.css");
}

/**
 * Include js files as necessary.
 *
 * This helper function is used by ctools but can also be used in other
 * modules in the same way as explained in the comments of ctools_include.
 *
 * @param $file
 *   The base file name to be included.
 * @param $module
 *   Optional module containing the include.
 * @param $dir
 *   Optional subdirectory containing the include file.
 */
function ctools_add_js($file, $module = 'ctools', $dir = 'js') {
  drupal_add_js(drupal_get_path('module', $module) . "/$dir/$file.js");
}

/**
 * Central static variable storage. Modeled after Drupal 7's drupal_static().
 *
 * @param $name
 *   Globally unique name for the variable. For a function with only one static,
 *   variable, the function name (e.g. via the PHP magic __FUNCTION__ constant)
 *   is recommended. For a function with multiple static variables add a
 *   distinguishing suffix to the function name for each one.
 * @param $default_value
 *   Optional default value.
 * @param $reset
 *   TRUE to reset a specific named variable, or all variables if $name is NULL.
 *   Resetting every variable should only be used, for example, for running unit
 *   tests with a clean environment. Should be used only though via function
 *   ctools_static_reset().
 */
function &ctools_static($name, $default_value = NULL, $reset = FALSE) {
  static $data = array();

  // Reset a single value, or all values.
  if ($reset) {
    if (isset($name)) {
      unset($data[$name]);
    }
    else {
      $data = array();
    }
    // We must return a reference to a variable.
    $dummy = NULL;
    return $dummy;
  }

  if (!isset($data[$name])) {
    $data[$name] = $default_value;
  }

  return $data[$name];
}

/**
 * Reset one or all centrally stored static variable(s).
 * Modeled after Drupal 7's drupal_static_reset().
 *
 * @param $name
 *   Name of the static variable to reset. Omit to reset all variables.
 */
function ctools_static_reset($name) {
  ctools_static($name, NULL, TRUE);
}

/**
 * Get a list of roles in the system.
 *
 * @return
 *   An array of role names keyed by role ID.
 */
function ctools_get_roles() {
  static $roles = NULL;
  if (!isset($roles)) {
    $roles = array();
    $result = db_query("SELECT r.rid, r.name FROM {role} r ORDER BY r.name");
    while ($obj = db_fetch_object($result)) {
      $roles[$obj->rid] = $obj->name;
    }
  }

  return $roles;
}

/*
 * Break x,y,z and x+y+z into an array. Numeric only.
 *
 * @param $str
 *   The string to parse.
 *
 * @return $object
 *   An object containing
 *   - operator: Either 'and' or 'or'
 *   - value: An array of numeric values.
 */
function ctools_break_phrase($str) {
  $object = new stdClass();

  if (preg_match('/^([0-9]+[+ ])+[0-9]+$/', $str)) {
    // The '+' character in a query string may be parsed as ' '.
    $object->operator = 'or';
    $object->value = preg_split('/[+ ]/', $str);
  }
  else if (preg_match('/^([0-9]+,)*[0-9]+$/', $str)) {
    $object->operator = 'and';
    $object->value = explode(',', $str);
  }

  // Keep an 'error' value if invalid strings were given.
  if (!empty($str) && (empty($object->value) || !is_array($object->value))) {
    $object->value = array(-1);
    $object->invalid_input = TRUE;
    return $object;
  }

  if (empty($object->value)) {
    $object->value = array();
  }

  // Doubly ensure that all values are numeric only.
  foreach ($object->value as $id => $value) {
    $object->value[$id] = intval($value);
  }

  return $object;
}

/**
 * Set a token/value pair to be replaced later in the request, specifically in
 * ctools_preprocess_page().
 *
 * @param $token
 *   The token to be replaced later, during page rendering.  This should
 *    ideally be a string inside of an HTML comment, so that if there is
 *    no replacement, the token will not render on the page.
 * @param $type
 *   The type of the token. Can be either 'variable', which will pull data
 *   directly from the page variables
 * @param $argument
 *   If $type == 'variable' then argument should be the key to fetch from
 *   the $variables. If $type == 'callback' then it should either be the
 *   callback, or an array that will be sent to call_user_func_array().
 *
 * @return
 *   A array of token/variable names to be replaced.
 */
function ctools_set_page_token($token = NULL, $type = NULL, $argument = NULL) {
  static $tokens = array();

  if (isset($token)) {
    $tokens[$token] = array($type, $argument);
  }

  return $tokens;
}

/**
 * Easily set a token from the page variables.
 *
 * This function can be used like this:
 * $token = ctools_set_variable_token('tabs');
 *
 * $token will then be a simple replacement for the 'tabs' about of the
 * variables available in the page template.
 */
function ctools_set_variable_token($token) {
  $string = '<!-- ctools-page-' . $token . ' -->';
  ctools_set_page_token($string, 'variable', $token);
  return $string;
}

/**
 * Easily set a token from the page variables.
 *
 * This function can be used like this:
 * $token = ctools_set_variable_token('id', 'mymodule_myfunction');
 */
function ctools_set_callback_token($token, $callback) {
  // If the callback uses arguments they are considered in the token.
  if (is_array($callback)) {
    $token .= '-' . md5(serialize($callback));
  }
  $string = '<!-- ctools-page-' . $token . ' -->';
  ctools_set_page_token($string, 'callback', $callback);
  return $string;
}

// -----------------------------------------------------------------------
// Drupal core hooks

/**
 * Implement hook_init to keep our global CSS at the ready.
 */
function ctools_init() {
  ctools_add_css('ctools');
  // If we are sure that CTools' AJAX is in use, change the error handling.
  if (!empty($_REQUEST['ctools_ajax'])) {
    ini_set('display_errors', 0);
    register_shutdown_function('ctools_shutdown_handler');
  }

  // Clear plugin cache on the module page submit.
  if ($_GET['q'] == 'admin/build/modules/list/confirm' && !empty($_POST)) {
    cache_clear_all('ctools_plugin_files:', 'cache', TRUE);
  }
}

/**
 * Shutdown handler used during ajax operations to help catch fatal errors.
 */
function ctools_shutdown_handler() {
  if (function_exists('error_get_last') AND ($error = error_get_last())){
    switch($error['type']){
      case E_ERROR:
      case E_CORE_ERROR:
      case E_COMPILE_ERROR:
      case E_USER_ERROR:
        // Do this manually because including files here is dangerous.
        $commands = array(
          array(
            'command' => 'alert',
            'title' => t('Error'),
            'text' => t('Unable to complete operation. Fatal error in @file on line @line: @message', array(
              '@file' => $error['file'],
              '@line' => $error['line'],
              '@message' => $error['message'],
            )),
          ),
        );

        // Change the status code so that the client will read the AJAX returned.
        header('HTTP/1.1 200 OK');
        drupal_json($commands);
    }
  }
}

/**
 * Implementation of hook_theme().
 */
function ctools_theme() {
  ctools_include('utility');
  $items = array();
  ctools_passthrough('ctools', 'theme', $items);
  return $items;
}

/**
 * Implementation of hook_menu().
 */
function ctools_menu() {
  ctools_include('utility');
  $items = array();
  ctools_passthrough('ctools', 'menu', $items);
  return $items;
}

/**
 * Implementation of hook_cron. Clean up old caches.
 */
function ctools_cron() {
  ctools_include('utility');
  $items = array();
  ctools_passthrough('ctools', 'cron', $items);
}

/**
 * Ensure the CTools CSS cache is flushed whenever hook_flush_caches is invoked.
 */
function ctools_flush_caches() {
  // Do not actually flush caches if running on cron. Drupal uses this hook
  // in an inconsistent fashion and it does not necessarily mean to *flush*
  // caches when running from cron. Instead it's just getting a list of cache
  // tables and may not do any flushing.
  if (variable_get('cron_semaphore', FALSE)) {
    return;
  }

  ctools_include('css');
  ctools_css_flush_caches();
}

/**
 * Provide a search form with a different id so that form_alters will miss it
 * and thus not get advanced search settings.
 */
function ctools_forms() {
  $forms['ctools_search_form']= array(
    'callback' => 'search_form',
  );

  return $forms;
}

/**
 * Implements hook_form_alter().
 */
function ctools_form_alter(&$form, $form_state, $form_id) {
  $form['#after_build'][] = 'ctools_ajax_form_after_build';
}

/**
 * #after_build callback: Mark the $form['#action'] as a trusted URL for Ajax.
 */
function ctools_ajax_form_after_build($form, $form_state) {
  $settings = array(
    'CToolsUrlIsAjaxTrusted' => array(
      $form['#action'] => TRUE,
    ),
  );
  drupal_add_js($settings, 'setting');
  return $form;
}

/**
 * Implementation of hook_file_download()
 *
 * When using the private file system, we have to let Drupal know it's ok to
 * download CSS and image files from our temporary directory.
 */
function ctools_file_download($filepath) {
  if (strpos($filepath, 'ctools') === 0) {
    $mime = file_get_mimetype($filepath);
    // For safety's sake, we allow only text and images.
    if (strpos($mime, 'text') === 0 || strpos($mime, 'image') === 0) {
      return array('Content-type:' . $mime);
    }
  }
}

// -----------------------------------------------------------------------
// CTools hook implementations.

/**
 * Implementation of hook_ctools_plugin_directory() to let the system know
 * where all our own plugins are.
 */
function ctools_ctools_plugin_directory($owner, $plugin_type) {
  if ($owner == 'ctools') {
    return 'plugins/' . $plugin_type;
  }
}

/**
 * Implementation of hook_js_replacements().
 * This is a hook that is not a standard yet. We hope jquery_update and others
 * will expose this hook to inform modules which scripts they are modifying
 * in the theme layer.
 * The return format is $scripts[$type][$old_path] = $new_path.
 */
function ctools_js_replacements() {
  $replacements = array();
  // Until jquery_update is released with its own replacement hook, we will
  // take those replacements into account here.
  if (module_exists('jquery_update')) {
    $replacements = array_merge_recursive($replacements, jquery_update_get_replacements());
    foreach ($replacements as $type => $type_replacements) {
      foreach ($type_replacements as $old_path => $new_filename) {
        $replacements[$type][$old_path] = drupal_get_path('module', 'jquery_update') . "/replace/$new_filename";
      }
    }
    $replacements['core']['misc/jquery.js'] = jquery_update_jquery_path();
  }
  return $replacements;
}

/**
 * Inform CTools that the layout plugin can be loaded from themes.
 */
function ctools_ctools_plugin_access() {
  return array(
    'child plugins' => TRUE,
  );
}

// -----------------------------------------------------------------------
// Drupal theme preprocess hooks that must be in the .module file.

/**
 * Override or insert PHPTemplate variables into the templates.
 *
 * This needs to be in the .module file to ensure availability; we can't change the
 * paths or it won't be able to find templates.
 */
function ctools_garland_preprocess_page(&$vars) {
  $vars['tabs2'] = ctools_menu_secondary_local_tasks();

  // Hook into color.module
  if (module_exists('color')) {
    _color_page_alter($vars);
  }
}

/**
 * A theme preprocess function to automatically allow panels-based node
 * templates based upon input when the panel was configured.
 */
function ctools_preprocess_node(&$vars) {
  // The 'panel_identifier' attribute of the node is added when the pane is
  // rendered.
  if (!empty($vars['node']->panel_identifier)) {
    $vars['panel_identifier'] = check_plain($vars['node']->panel_identifier);
    $vars['template_files'][] = 'node-panel-' . check_plain($vars['node']->panel_identifier);
  }
}

/**
 * A theme preprocess function to allow content type plugins to use page
 * template variables which are not yet available when the content type is
 * rendered.
 */
function ctools_preprocess_page(&$variables) {
  $tokens = ctools_set_page_token();
  if (!empty($tokens)) {
    $temp_tokens = array();
    foreach ($tokens as $token => $key) {
      list($type, $argument) = $key;
      switch ($type) {
        case 'variable':
          $temp_tokens[$token] = isset($variables[$argument]) ? $variables[$argument] : '';
          break;
        case 'callback':
          if (is_string($argument) && function_exists($argument)) {
            $temp_tokens[$token] = $argument($variables);
          }
          if (is_array($argument) && function_exists($argument[0])) {
            $function = array_shift($argument);
            $argument = array_merge(array(&$variables), $argument);
            $temp_tokens[$token] = call_user_func_array($function, $argument);
          }
          break;
      }
    }
    $tokens = $temp_tokens;
    unset($temp_tokens);
    $variables['content'] = strtr($variables['content'], $tokens);
  }

  if (defined('CTOOLS_AJAX_INCLUDED')) {
    ctools_ajax_page_preprocess($variables);
  }
}

// -----------------------------------------------------------------------
// Menu callbacks that must be in the .module file.

/**
 * Determine if the current user has access via a plugin.
 *
 * This function is meant to be embedded in the Drupal menu system, and
 * therefore is in the .module file since sub files can't be loaded, and
 * takes arguments a little bit more haphazardly than ctools_access().
 *
 * @param $access
 *   An access control array which contains the following information:
 *   - 'logic': and or or. Whether all tests must pass or one must pass.
 *   - 'plugins': An array of access plugins. Each contains:
 *   - - 'name': The name of the plugin
 *   - - 'settings': The settings from the plugin UI.
 *   - - 'context': Which context to use.
 * @param ...
 *   zero or more context arguments generated from argument plugins. These
 *   contexts must have an 'id' attached to them so that they can be
 *   properly associated. The argument plugin system should set this, but
 *   if the context is coming from elsewhere it will need to be set manually.
 *
 * @return
 *   TRUE if access is granted, false if otherwise.
 */
function ctools_access_menu($access) {
  // Short circuit everything if there are no access tests.
  if (empty($access['plugins'])) {
    return TRUE;
  }

  $contexts = array();
  foreach (func_get_args() as $arg) {
    if (is_object($arg) && get_class($arg) == 'ctools_context') {
      $contexts[$arg->id] = $arg;
    }
  }

  ctools_include('context');
  return ctools_access($access, $contexts);
}

/**
 * Determine if the current user has access via checks to multiple different
 * permissions.
 *
 * This function is a thin wrapper around user_access that allows multiple
 * permissions to be easily designated for use on, for example, a menu callback.
 *
 * @param ...
 *   An indexed array of zero or more permission strings to be checked by
 *   user_access().
 *
 * @return
 *   Iff all checks pass will this function return TRUE. If an invalid argument
 *   is passed (e.g., not a string), this function errs on the safe said and
 *   returns FALSE.
 */
function ctools_access_multiperm() {
  foreach (func_get_args() as $arg) {
    if (!is_string($arg) || !user_access($arg)) {
      return FALSE;
    }
  }
  return TRUE;
}

/**
 * Check to see if the incoming menu item is js capable or not.
 *
 * This can be used as %ctools_js as part of a path in hook menu. CTools
 * ajax functions will automatically change the phrase 'nojs' to 'ajax'
 * when it attaches ajax to a link. This can be used to autodetect if
 * that happened.
 */
function ctools_js_load($js) {
  if ($js == 'ajax') {
    return TRUE;
  }
  return 0;
}

/**
 * Menu _load hook.
 *
 * This function will be called to load an object as a replacement for
 * %ctools_export_ui in menu paths.
 */
function ctools_export_ui_load($item_name, $plugin_name) {
  $return = &ctools_static(__FUNCTION__, FALSE);

  if (!$return) {
    ctools_include('export-ui');
    $plugin = ctools_get_export_ui($plugin_name);

    if ($plugin) {
      // Get the load callback.
      $item = ctools_export_crud_load($plugin['schema'], $item_name);
      return empty($item) ? FALSE : $item;
    }
  }

  return $return;
}

// -----------------------------------------------------------------------
// Caching callbacks on behalf of export-ui.

/**
 * Menu access callback for various tasks of export-ui.
 */
function ctools_export_ui_task_access($plugin_name, $op, $item = NULL) {
  ctools_include('export-ui');
  $plugin = ctools_get_export_ui($plugin_name);
  $handler = ctools_export_ui_get_handler($plugin);

  if ($handler) {
    return $handler->access($op, $item);
  }

  // Deny access if the handler cannot be found.
  return FALSE;
}

/**
 * Cache callback on behalf of ctools_export_ui.
 */
function ctools_export_ui_context_cache_get($plugin_name, $key) {
  ctools_include('export-ui');
  $plugin = ctools_get_export_ui($plugin_name);
  $handler = ctools_export_ui_get_handler($plugin);
  if ($handler) {
    $item = $handler->edit_cache_get($key);
    if (!$item) {
      $item = ctools_export_crud_load($handler->plugin['schema'], $key);
    }
    return $item;
  }
}

/**
 * Cache callback on behalf of ctools_export_ui.
 */
function ctools_export_ui_context_cache_set($plugin_name, $key, $item) {
  ctools_include('export-ui');
  $plugin = ctools_get_export_ui($plugin_name);
  $handler = ctools_export_ui_get_handler($plugin);
  if ($handler) {
    return $handler->edit_cache_set_key($item, $key);
  }
}

/**
 * Callback for access control ajax form on behalf of export ui.
 *
 * Returns the cached access config and contexts used.
 * Note that this is assuming that access will be in $item->access -- if it
 * is not, an export UI plugin will have to make its own callbacks.
 */
function ctools_export_ui_ctools_access_get($argument) {
  ctools_include('export-ui');
  list($plugin_name, $key) = explode(':', $argument);

  $plugin = ctools_get_export_ui($plugin_name);
  $handler = ctools_export_ui_get_handler($plugin);

  if ($handler) {
    ctools_include('context');
    $item = $handler->edit_cache_get($key);
    if (!$item) {
      $item = ctools_export_crud_load($handler->plugin['schema'], $key);
    }

    $contexts = ctools_context_load_contexts($item);
    return array($item->access, $contexts);
  }
}

/**
 * Callback for access control ajax form on behalf of export ui
 *
 * Returns the cached access config and contexts used.
 * Note that this is assuming that access will be in $item->access -- if it
 * is not, an export UI plugin will have to make its own callbacks.
 */
function ctools_export_ui_ctools_access_set($argument, $access) {
  ctools_include('export-ui');
  list($plugin_name, $key) = explode(':', $argument);

  $plugin = ctools_get_export_ui($plugin_name);
  $handler = ctools_export_ui_get_handler($plugin);

  if ($handler) {
    ctools_include('context');
    $item = $handler->edit_cache_get($key);
    if (!$item) {
      $item = ctools_export_crud_load($handler->plugin['schema'], $key);
    }
    $item->access = $access;
    return $handler->edit_cache_set_key($item, $key);
  }
}