Club Drupal

<?php

/**

 * @file

 *

 * Contains routines to organize and load plugins. It allows a special

 * variation of the hook system so that plugins can be kept in separate

 * .inc files, and can be either loaded all at once or loaded only when

 * necessary.

 */

/**

 * Get an array of information about modules that support an API.

 *

 * This will ask each module if they support the given API, and if they do

 * it will return an array of information about the modules that do.

 *

 * This function invokes hook_ctools_api. This invocation is statically

 * cached, so feel free to call it as often per page run as you like, it

 * will cost very little.

 *

 * This function can be used as an alternative to module_implements and can

 * thus be used to find a precise list of modules that not only support

 * a given hook (aka 'api') but also restrict to only modules that use

 * the given version. This will allow multiple modules moving at different

 * paces to still be able to work together and, in the event of a mismatch,

 * either fall back to older behaviors or simply cease loading, which is

 * still better than a crash.

 *

 * @param $owner

 *   The name of the module that controls the API.

 * @param $api

 *   The name of the api. The api name forms the file name:

 *   $module.$api.inc

 * @param $minimum_version

 *   The lowest version API that is compatible with this one. If a module

 *   reports its API as older than this, its files will not be loaded. This

 *   should never change during operation.

 * @param $current_version

 *   The current version of the api. If a module reports its minimum API as

 *   higher than this, its files will not be loaded. This should never change

 *   during operation.

 *

 * @return

 *   An array of API information, keyed by module. Each module's information will

 *   contain:

 *   - 'version': The version of the API required by the module. The module

 *     should use the lowest number it can support so that the widest range

 *     of supported versions can be used.

 *   - 'path': If not provided, this will be the module's path. This is

 *     where the module will store any subsidiary files. This differs from

 *     plugin paths which are figured separately.

 *

 *   APIs can request any other information to be placed here that they might

 *   need. This should be in the documentation for that particular API.

 */

function ctools_plugin_api_info($owner, $api, $minimum_version, $current_version) {

  $cache = &drupal_static(__FUNCTION__, array());

  if (!isset($cache[$owner][$api])) {

    $cache[$owner][$api] = array();

    $hook = ctools_plugin_api_get_hook($owner, $api);

    foreach (module_implements($hook) as $module) {

      $function = $module . '_' . $hook;

      $info = $function($owner, $api);

      $version = NULL;

      // This is added to make hook_views_api() compatible with this, since

      // views used a different version key.

      if (isset($info['version'])) {

        $version = $info['version'];

      }

      else if (isset($info['api'])) {

        $version = $info['api'];

      }

      if (!isset($version)) {

        continue;

      }

      // Only process if version is between minimum and current, inclusive.

      if (($version == $minimum_version) || ($version == $current_version)

        || (version_compare($version, $minimum_version, '>=')

        && version_compare($version, $current_version, '<='))) {

        if (!isset($info['path'])) {

          $info['path'] = drupal_get_path('module', $module);

        }

        $cache[$owner][$api][$module] = $info;

      }

    }

    // And allow themes to implement these as well.

    $themes = _ctools_list_themes();

    foreach ($themes as $name => $theme) {

      if (!empty($theme->info['api'][$owner][$api])) {

        $info = $theme->info['api'][$owner][$api];

        if (!isset($info['version'])) {

          continue;

        }

        // Only process if version is between minimum and current, inclusive.

      if (version_compare($info['version'], $minimum_version, '>=') && version_compare($info['version'], $current_version, '<=')) {

          if (!isset($info['path'])) {

            $info['path'] = '';

          }

          // Because themes can't easily specify full path, we add it here

          // even though we do not for modules:

          $info['path'] = drupal_get_path('theme', $name) . '/' . $info['path'];

          $cache[$owner][$api][$name] = $info;

        }

      }

    }

    // Allow other modules to hook in.

    drupal_alter($hook, $cache[$owner][$api], $owner, $api);

  }

  return $cache[$owner][$api];

}

/**

 * Load a group of API files.

 *

 * This will ask each module if they support the given API, and if they do

 * it will load the specified file name. The API and the file name

 * coincide by design.

 *

 * @param $owner

 *   The name of the module that controls the API.

 * @param $api

 *   The name of the api. The api name forms the file name:

 *   $module.$api.inc, though this can be overridden by the module's response.

 * @param $minimum_version

 *   The lowest version API that is compatible with this one. If a module

 *   reports its API as older than this, its files will not be loaded. This

 *   should never change during operation.

 * @param $current_version

 *   The current version of the api. If a module reports its minimum API as

 *   higher than this, its files will not be loaded. This should never change

 *   during operation.

 *

 * @return

 *   The API information, in case you need it.

 */

function ctools_plugin_api_include($owner, $api, $minimum_version, $current_version) {

  static $already_done = array();

  $info = ctools_plugin_api_info($owner, $api, $minimum_version, $current_version);

  foreach ($info as $module => $plugin_info) {

    if (!isset($already_done[$owner][$api][$module])) {

      if (isset($plugin_info["$api file"])) {

        $file = $plugin_info["$api file"];

      }

      else if (isset($plugin_info['file'])) {

        $file = $plugin_info['file'];

      }

      else {

        $file = "$module.$api.inc";

      }

      if (file_exists(DRUPAL_ROOT . "/$plugin_info[path]/$file")) {

        require_once DRUPAL_ROOT . "/$plugin_info[path]/$file";

      }

      else if (file_exists(DRUPAL_ROOT . "/$file")) {

        require_once DRUPAL_ROOT . "/$file";

      }

      $already_done[$owner][$api][$module] = TRUE;

    }

  }

  return $info;

}

/**

 * Find out what hook to use to determine if modules support an API.

 *

 * By default, most APIs will use hook_ctools_plugin_api, but some modules

 * want sole ownership. This technique lets modules define what hook

 * to use.

 */

function ctools_plugin_api_get_hook($owner, $api) {

  // Allow modules to use their own hook for this. The only easy way to do

  // this right now is with a magically named function.

  if (function_exists($function = $owner . '_' . $api . '_hook_name')) {

    $hook = $function();

  }

  else if (function_exists($function = $owner . '_ctools_plugin_api_hook_name')) {

    $hook = $function();

  }

  // Do this last so that if the $function above failed to return, we have a

  // sane default.

  if (empty($hook)) {

    $hook = 'ctools_plugin_api';

  }

  return $hook;

}

/**

 * Fetch a group of plugins by name.

 *

 * @param string $module

 *   The name of the module that utilizes this plugin system. It will be used to

 *   get more data about the plugin as defined on hook_ctools_plugin_type().

 * @param string $type

 *   The type identifier of the plugin.

 * @param string $id

 *   If specified, return only information about plugin with this identifier.

 *   The system will do its utmost to load only plugins with this id.

 *

 * @return array

 *   An array of information arrays about the plugins received. The contents of

 *   the array are specific to the plugin.

 */

function ctools_get_plugins($module, $type, $id = NULL) {

  // Store local caches of plugins and plugin info so we don't have to do full

  // lookups every time.

  static $drupal_static_fast;

  if (!isset($drupal_static_fast)) {

    $drupal_static_fast['plugins'] = &drupal_static('ctools_plugins', array());

  }

  $plugins = &$drupal_static_fast['plugins'];

  $info = ctools_plugin_get_plugin_type_info();

  if (!isset($info[$module][$type])) {

    // If we don't find the plugin we attempt a cache rebuild before bailing out

    $info = ctools_plugin_get_plugin_type_info(TRUE);

    // Bail out noisily if an invalid module/type combination is requested.

    if (!isset($info[$module][$type])) {

      watchdog('ctools', 'Invalid plugin module/type combination requested: module @module and type @type', array('@module' => $module, '@type' => $type), WATCHDOG_ERROR);

      return array();

    }

  }

  // Make sure our plugins array is populated.

  if (!isset($plugins[$module][$type])) {

    $plugins[$module][$type] = array();

  }

  // Attempt to shortcut this whole piece of code if we already have the

  // requested plugin:

  if ($id && array_key_exists($id, $plugins[$module][$type])) {

    return $plugins[$module][$type][$id];

  }

  // Store the status of plugin loading. If a module plugin type pair is true,

  // then it is fully loaded and no searching or setup needs to be done.

  $setup = &drupal_static('ctools_plugin_setup', array());

  // We assume we don't need to build a cache.

  $build_cache = FALSE;

  // If the plugin info says this can be cached, check cache first.

  if ($info[$module][$type]['cache'] && empty($setup[$module][$type])) {

    $cache = cache_get("plugins:$module:$type", $info[$module][$type]['cache table']);

    if (!empty($cache->data)) {

      // Cache load succeeded so use the cached plugin list.

      $plugins[$module][$type]   = $cache->data;

      // Set $setup to true so we know things where loaded.

      $setup[$module][$type]     = TRUE;

    }

    else {

      // Cache load failed so store that we need to build and write the cache.

      $build_cache = TRUE;

    }

  }

  // Always load all hooks if we need them. Note we only need them now if the

  // plugin asks for them. We can assume that if we have plugins we've already

  // called the global hook.

  if (!empty($info[$module][$type]['use hooks']) && empty($plugins[$module][$type])) {

    $plugins[$module][$type] = ctools_plugin_load_hooks($info[$module][$type]);

  }

  // Then see if we should load all files. We only do this if we want a list of

  // all plugins or there was a cache miss.

  if (empty($setup[$module][$type]) && ($build_cache || !$id)) {

    $setup[$module][$type] = TRUE;

    $plugins[$module][$type] = array_merge($plugins[$module][$type], ctools_plugin_load_includes($info[$module][$type]));

    // If the plugin can have child plugins, and we're loading all plugins,

    // go through the list of plugins we have and find child plugins.

    if (!$id && !empty($info[$module][$type]['child plugins'])) {

      // If a plugin supports children, go through each plugin and ask.

      $temp = array();

      foreach ($plugins[$module][$type] as $name => $plugin) {

        // The strpos ensures that we don't try to find children for plugins

        // that are already children.

        if (!empty($plugin['get children']) && function_exists($plugin['get children']) && strpos($name, ':') === FALSE) {

          $temp = array_merge($plugin['get children']($plugin, $name), $temp);

        }

        else {

          $temp[$name] = $plugin;

        }

      }

      $plugins[$module][$type] = $temp;

    }

  }

  // If we were told earlier that this is cacheable and the cache was empty,

  // give something back.

  if ($build_cache) {

    cache_set("plugins:$module:$type", $plugins[$module][$type], $info[$module][$type]['cache table']);

  }

  // If no id was requested, we are finished here:

  if (!$id) {

    // Use array_filter because looking for unknown plugins could cause NULL

    // entries to appear in the list later.

    return array_filter($plugins[$module][$type]);

  }

  // Check to see if we need to look for the file

  if (!array_key_exists($id, $plugins[$module][$type])) {

    // If we can have child plugins, check to see if the plugin name is in the

    // format of parent:child and break it up if it is.

    if (!empty($info[$module][$type]['child plugins']) && strpos($id, ':') !== FALSE) {

      list($parent, $child) = explode(':', $id, 2);

    }

    else {

      $parent = $id;

    }

    if (!array_key_exists($parent, $plugins[$module][$type])) {

      $result = ctools_plugin_load_includes($info[$module][$type], $parent);

      // Set to either what was returned or NULL.

      $plugins[$module][$type][$parent] = isset($result[$parent]) ? $result[$parent] : NULL;

    }

    // If we are looking for a child, and have the parent, ask the parent for the child.

    if (!empty($child) && !empty($plugins[$module][$type][$parent]) && function_exists($plugins[$module][$type][$parent]['get child'])) {

      $plugins[$module][$type][$id] = $plugins[$module][$type][$parent]['get child']($plugins[$module][$type][$parent], $parent, $child);

    }

  }

  // At this point we should either have the plugin, or a NULL.

  return $plugins[$module][$type][$id];

}

/**

 * Return the full list of plugin type info for all plugin types registered in

 * the current system.

 *

 * This function manages its own cache getting/setting, and should always be

 * used as the way to initially populate the list of plugin types. Make sure you

 * call this function to properly populate the ctools_plugin_type_info static

 * variable.

 *

 * @return array

 *   A multilevel array of plugin type info, the outer array keyed on module

 *   name and each inner array keyed on plugin type name.

 */

function ctools_plugin_get_plugin_type_info($flush = FALSE) {

  static $drupal_static_fast;

  if (!isset($drupal_static_fast)) {

    $drupal_static_fast['info_loaded'] = &drupal_static('ctools_plugin_type_info_loaded', FALSE);

    $drupal_static_fast['all_type_info'] = &drupal_static('ctools_plugin_type_info', array());

  }

  $info_loaded = &$drupal_static_fast['info_loaded'];

  $all_type_info = &$drupal_static_fast['all_type_info'];

  // Only trigger info loading once.

  if ($info_loaded && !$flush) {

    return $all_type_info;

  }

  $info_loaded = TRUE;

  $cache = cache_get('ctools_plugin_type_info');

  if (!empty($cache->data) && !$flush) {

    // Plugin type info cache is warm, use it.

    $all_type_info = $cache->data;

  }

  else {

    // Cache expired, refill it.

    foreach (module_implements('ctools_plugin_type') as $module) {

      $module_infos = array();

      $function = $module . '_ctools_plugin_type';

      $module_infos = $function();

      foreach ($module_infos as $plugin_type_name => $plugin_type_info) {

        // Apply defaults. Array addition will not overwrite pre-existing keys.

        $plugin_type_info += array(

          'module' => $module,

          'type' => $plugin_type_name,

          'cache' => FALSE,

          'cache table' => 'cache',

          'classes' => array(),

          'use hooks' => FALSE,

          'defaults' => array(),

          'process' => '',

          'alterable' => TRUE,

          'extension' => 'inc',

          'info file' => FALSE,

          'hook' => $module . '_' . $plugin_type_name,

          'load themes' => FALSE,

        );

        $all_type_info[$module][$plugin_type_name] = $plugin_type_info;

      }

    }

    cache_set('ctools_plugin_type_info', $all_type_info);

  }

  return $all_type_info;

}

/**

 * Reset all static caches that affect the result of ctools_get_plugins().

 */

function ctools_get_plugins_reset() {

  drupal_static_reset('ctools_plugins');

  drupal_static_reset('ctools_plugin_setup');

  drupal_static_reset('ctools_plugin_load_includes');

  drupal_static_reset('ctools_plugin_api_info');

}

/**

 * Load plugins from a directory.

 *

 * @param $info

 *   The plugin info as returned by ctools_plugin_get_info()

 * @param $file

 *   The file to load if we're looking for just one particular plugin.

 *

 * @return

 *   An array of information created for this plugin.

 */

function ctools_plugin_load_includes($info, $filename = NULL) {

  // Keep a static array so we don't hit file_scan_directory more than necessary.

  $all_files = &drupal_static(__FUNCTION__, array());

  // store static of plugin arrays for reference because they can't be reincluded.

  static $plugin_arrays = array();

  if (!isset($all_files[$info['module']][$info['type']])) {

    $cache = cache_get("ctools_plugin_files:$info[module]:$info[type]");

    if ($cache) {

      $all_files[$info['module']][$info['type']] = $cache->data;

    }

    // Do not attempt any file scan even if the cached entry was empty.

    // A NULL entry here would mean the plugin just does not exists, and we

    // cannot afford to run file scan on production sites normal run.

    elseif (!isset($all_files[$info['module']][$info['type']])) {

      $all_files[$info['module']][$info['type']] = array();

      // Load all our plugins.

      $directories = ctools_plugin_get_directories($info);

      $extension = (empty($info['info file']) || ($info['extension'] != 'inc')) ? $info['extension'] : 'info';

      foreach ($directories as $module => $path) {

        $all_files[$info['module']][$info['type']][$module] = file_scan_directory($path, '/\.' . $extension . '$/', array('key' => 'name'));

      }

      cache_set("ctools_plugin_files:$info[module]:$info[type]", $all_files[$info['module']][$info['type']]);

    }

  }

  $file_list = $all_files[$info['module']][$info['type']];

  $plugins = array();

  // Iterate through all the plugin .inc files, load them and process the hook

  // that should now be available.

  foreach (array_filter($file_list) as $module => $files) {

    if ($filename) {

      $files = isset($files[$filename]) ? array($filename => $files[$filename]) : array();

    }

    foreach ($files as $file) {

      if (!empty($info['info file'])) {

        // Parse a .info file

        $result = ctools_plugin_process_info($info, $module, $file);

      }

      else {

        // Parse a hook.

        $plugin = NULL; // ensure that we don't have something leftover from earlier.

        if (isset($plugin_arrays[$file->uri])) {

          $identifier = $plugin_arrays[$file->uri];

        }

        else {

          include_once DRUPAL_ROOT . '/' . $file->uri;

          // .inc files have a special format for the hook identifier.

          // For example, 'foo.inc' in the module 'mogul' using the plugin

          // whose hook is named 'borg_type' should have a function named (deep breath)

          // mogul_foo_borg_type()

          // If, however, the .inc file set the quasi-global $plugin array, we

          // can use that and not even call a function. Set the $identifier

          // appropriately and ctools_plugin_process() will handle it.

          if (isset($plugin)) {

            $plugin_arrays[$file->uri] = $plugin;

            $identifier = $plugin;

          }

          else {

            $identifier = $module . '_' . $file->name;

          }

        }

        $result = ctools_plugin_process($info, $module, $identifier, dirname($file->uri), basename($file->uri), $file->name);

      }

      if (is_array($result)) {

        $plugins = array_merge($plugins, $result);

      }

    }

  }

  return $plugins;

}

/**

 * Get a list of directories to search for plugins of the given type.

 *

 * This utilizes hook_ctools_plugin_directory() to determine a complete list of

 * directories. Only modules that implement this hook and return a string

 * value will have their directories included.

 *

 * @param $info

 *   The $info array for the plugin as returned by ctools_plugin_get_info().

 *

 * @return array $directories

 *   An array of directories to search.

 */

function ctools_plugin_get_directories($info) {

  $directories = array();

  foreach (module_implements('ctools_plugin_directory') as $module) {

    $function = $module . '_ctools_plugin_directory';

    $result = $function($info['module'], $info['type']);

    if ($result && is_string($result)) {

      $directories[$module] = drupal_get_path('module', $module) . '/' . $result;

    }

  }

  if (!empty($info['load themes'])) {

    $themes = _ctools_list_themes();

    foreach ($themes as $name => $theme) {

      if (!empty($theme->info['plugins'][$info['module']][$info['type']])) {

        $directories[$name] = drupal_get_path('theme', $name) . '/' . $theme->info['plugins'][$info['module']][$info['type']];

      }

    }

  }

  return $directories;

}

/**

 * Helper function to build a ctools-friendly list of themes capable of

 * providing plugins.

 *

 * @return array $themes

 *   A list of themes that can act as plugin providers, sorted parent-first with

 *   the active theme placed last.

 */

function _ctools_list_themes() {

  static $themes;

  if (is_null($themes)) {

    $current = variable_get('theme_default', FALSE);

    $themes = $active = array();

    $all_themes = list_themes();

    foreach ($all_themes as $name => $theme) {

      // Only search from active themes

      if (empty($theme->status) && $theme->name != $current) {

        continue;

      }

      $active[$name] = $theme;

      // Prior to drupal 6.14, $theme->base_themes does not exist. Build it.

      if (!isset($theme->base_themes) && !empty($theme->base_theme)) {

        $active[$name]->base_themes = ctools_find_base_themes($all_themes, $name);

      }

    }

    // Construct a parent-first list of all themes

    foreach ($active as $name => $theme) {

      $base_themes = isset($theme->base_themes) ? $theme->base_themes : array();

      $themes = array_merge($themes, $base_themes, array($name => $theme->info['name']));

    }

    // Put the actual theme info objects into the array

    foreach (array_keys($themes) as $name) {

      if (isset($all_themes[$name])) {

        $themes[$name] = $all_themes[$name];

      }

    }

    // Make sure the current default theme always gets the last word

    if ($current_key = array_search($current, array_keys($themes))) {

      $themes += array_splice($themes, $current_key, 1);

    }

  }

  return $themes;

}

/**

 * Find all the base themes for the specified theme.

 *

 * Themes can inherit templates and function implementations from earlier themes.

 *

 * NOTE: this is a verbatim copy of system_find_base_themes(), which was not

 * implemented until 6.14. It is included here only as a fallback for outdated

 * versions of drupal core.

 *

 * @param $themes

 *   An array of available themes.

 * @param $key

 *   The name of the theme whose base we are looking for.

 * @param $used_keys

 *   A recursion parameter preventing endless loops.

 * @return

 *   Returns an array of all of the theme's ancestors; the first element's value

 *   will be NULL if an error occurred.

 */

function ctools_find_base_themes($themes, $key, $used_keys = array()) {

  $base_key = $themes[$key]->info['base theme'];

  // Does the base theme exist?

  if (!isset($themes[$base_key])) {

    return array($base_key => NULL);

  }

  $current_base_theme = array($base_key => $themes[$base_key]->info['name']);

  // Is the base theme itself a child of another theme?

  if (isset($themes[$base_key]->info['base theme'])) {

    // Do we already know the base themes of this theme?

    if (isset($themes[$base_key]->base_themes)) {

      return $themes[$base_key]->base_themes + $current_base_theme;

    }

    // Prevent loops.

    if (!empty($used_keys[$base_key])) {

      return array($base_key => NULL);

    }

    $used_keys[$base_key] = TRUE;

    return ctools_find_base_themes($themes, $base_key, $used_keys) + $current_base_theme;

  }

  // If we get here, then this is our parent theme.

  return $current_base_theme;

}

/**

 * Load plugin info for the provided hook; this is handled separately from

 * plugins from files.

 *

 * @param $info

 *   The info array about the plugin as created by ctools_plugin_get_info()

 *

 * @return

 *   An array of info supplied by any hook implementations.

 */

function ctools_plugin_load_hooks($info) {

  $hooks = array();

  foreach (module_implements($info['hook']) as $module) {

    $result = ctools_plugin_process($info, $module, $module, drupal_get_path('module', $module));

    if (is_array($result)) {

      $hooks = array_merge($hooks, $result);

    }

  }

  return $hooks;

}

/**

 * Process a single hook implementation of a ctools plugin.

 *

 * @param $info

 *   The $info array about the plugin as returned by ctools_plugin_get_info()

 * @param $module

 *   The module that implements the plugin being processed.

 * @param $identifier

 *   The plugin identifier, which is used to create the name of the hook

 *   function being called.

 * @param $path

 *   The path where files utilized by this plugin will be found.

 * @param $file

 *   The file that was loaded for this plugin, if it exists.

 * @param $base

 *   The base plugin name to use. If a file was loaded for the plugin, this

 *   is the plugin to assume must be present. This is used to automatically

 *   translate the array to make the syntax more friendly to plugin

 *   implementors.

 */

function ctools_plugin_process($info, $module, $identifier, $path, $file = NULL, $base = NULL) {

  if (is_array($identifier)) {

    $result = $identifier;

  }

  else {

    $function = $identifier . '_' . $info['hook'];

    if (!function_exists($function)) {

      return NULL;

    }

    $result = $function($info);

    if (!isset($result) || !is_array($result)) {

      return NULL;

    }

  }

  // Automatically convert to the proper format that lets plugin implementations

  // not nest arrays as deeply as they used to, but still support the older

  // format where they do:

  if ($base && (!isset($result[$base]) || !is_array($result[$base]))) {

    $result = array($base => $result);

  }

  return _ctools_process_data($result, $info, $module, $path, $file);

}

/**

 * Fill in default values and run hooks for data loaded for one or

 * more plugins.

 */

function _ctools_process_data($result, $plugin_type_info, $module, $path, $file) {

  // Fill in global defaults.

  foreach ($result as $name => $plugin) {

    $result[$name] += array(

      'module' => $module,

      'name' => $name,

      'path' => $path,

      'file' => $file,

      'plugin module' => $plugin_type_info['module'],

      'plugin type' => $plugin_type_info['type'],

    );

    // Fill in plugin-specific defaults, if they exist.

    if (!empty($plugin_type_info['defaults'])) {

      if (is_array($plugin_type_info['defaults'])) {

        $result[$name] += $plugin_type_info['defaults'];

      }

    }

    // Allow the plugin to be altered before processing.

    if (!empty($plugin_type_info['alterable']) && $plugin_type_info['alterable']) {

      drupal_alter('ctools_plugin_pre', $result[$name], $plugin_type_info);

    }

    // Allow the plugin owner to do additional processing.

    if (!empty($plugin_type_info['process']) && $function = ctools_plugin_get_function($plugin_type_info, 'process')) {

      $function($result[$name], $plugin_type_info);

    }

    // Allow the plugin to be altered after processing.

    if (!empty($plugin_type_info['alterable']) && $plugin_type_info['alterable']) {

      drupal_alter('ctools_plugin_post', $result[$name], $plugin_type_info);

    }

  }

  return $result;

}

/**

 * Process an info file for plugin information, rather than a hook.

 */

function ctools_plugin_process_info($info, $module, $file) {

  $result = drupal_parse_info_file($file->uri);

  if ($result) {

    $result = array($file->name => $result);

    return _ctools_process_data($result, $info, $module, dirname($file->uri), basename($file->uri));

  }

}

/**

 * Ask a module for info about a particular plugin type.

 */

function ctools_plugin_get_info($module, $type) {

  $all_info = ctools_plugin_get_plugin_type_info();

  return isset($all_info[$module][$type]) ? $all_info[$module][$type] : array();

}

/**

 * Get a function from a plugin, if it exists. If the plugin is not already

 * loaded, try ctools_plugin_load_function() instead.

 *

 * @param $plugin_definition

 *   The loaded plugin type.

 * @param $function_name

 *   The identifier of the function. For example, 'settings form'.

 *

 * @return

 *   The actual name of the function to call, or NULL if the function

 *   does not exist.

 */

function ctools_plugin_get_function($plugin_definition, $function_name) {

  // If cached the .inc file may not have been loaded. require_once is quite safe

  // and fast so it's okay to keep calling it.

  if (isset($plugin_definition['file'])) {

    // Plugins that are loaded from info files have the info file as

    // $plugin['file'].  Don't try to run those.

    $info = ctools_plugin_get_info($plugin_definition['plugin module'], $plugin_definition['plugin type']);

    if (empty($info['info file'])) {

      require_once DRUPAL_ROOT . '/' . $plugin_definition['path'] . '/' . $plugin_definition['file'];

    }

  }

  if (!isset($plugin_definition[$function_name])) {

    return;

  }

  if (is_array($plugin_definition[$function_name]) && isset($plugin_definition[$function_name]['function'])) {

    $function = $plugin_definition[$function_name]['function'];

    if (isset($plugin_definition[$function_name]['file'])) {

      $file = $plugin_definition[$function_name]['file'];

      if (isset($plugin_definition[$function_name]['path'])) {

        $file = $plugin_definition[$function_name]['path'] . '/' . $file;

      }

      require_once DRUPAL_ROOT . '/' . $file;

    }

  }

  else {

    $function = $plugin_definition[$function_name];

  }

  if (function_exists($function)) {

    return $function;

  }

}

/**

 * Load a plugin and get a function name from it, returning success only

 * if the function exists.

 *

 * @param $module

 *   The module that owns the plugin type.

 * @param $type

 *   The type of plugin.

 * @param $id

 *   The id of the specific plugin to load.

 * @param $function_name

 *   The identifier of the function. For example, 'settings form'.

 *

 * @return

 *   The actual name of the function to call, or NULL if the function

 *   does not exist.

 */

function ctools_plugin_load_function($module, $type, $id, $function_name) {

  $plugin = ctools_get_plugins($module, $type, $id);

  return ctools_plugin_get_function($plugin, $function_name);

}

/**

 * Get a class from a plugin, if it exists. If the plugin is not already

 * loaded, try ctools_plugin_load_class() instead.

 *

 * @param $plugin_definition

 *   The loaded plugin type.

 * @param $class_name

 *   The identifier of the class. For example, 'handler'.

 *

 * @return

 *   The actual name of the class to call, or NULL if the class does not exist.

 */

function ctools_plugin_get_class($plugin_definition, $class_name) {

  // If cached the .inc file may not have been loaded. require_once is quite safe

  // and fast so it's okay to keep calling it.

  if (isset($plugin_definition['file'])) {

    // Plugins that are loaded from info files have the info file as

    // $plugin['file'].  Don't try to run those.

    $info = ctools_plugin_get_info($plugin_definition['plugin module'], $plugin_definition['plugin type']);

    if (empty($info['info file'])) {

      require_once DRUPAL_ROOT . '/' . $plugin_definition['path'] . '/' . $plugin_definition['file'];

    }

  }

  $return = FALSE;

  if (!isset($plugin_definition[$class_name])) {

    return;

  }

  else if (is_string($plugin_definition[$class_name])) {

    // Plugin uses the string form shorthand.

    $return = $plugin_definition[$class_name];

  }

  else if (isset($plugin_definition[$class_name]['class'])) {

    // Plugin uses the verbose array form.

    $return = $plugin_definition[$class_name]['class'];

  }

  // @todo consider adding an else {watchdog(...)} here

  return ($return && class_exists($return)) ? $return : NULL;

}

/**

 * Load a plugin and get a class name from it, returning success only if the

 * class exists.

 *

 * @param $module

 *   The module that owns the plugin type.

 * @param $type

 *   The type of plugin.

 * @param $id

 *   The id of the specific plugin to load.

 * @param $class_name

 *   The identifier of the class. For example, 'handler'.

 *

 * @return

 *   The actual name of the class to call, or NULL if the class does not exist.

 */

function ctools_plugin_load_class($module, $type, $id, $class_name) {

  $plugin = ctools_get_plugins($module, $type, $id);

  return ctools_plugin_get_class($plugin, $class_name);

}

/**

 * Sort callback for sorting plugins naturally.

 *

 * Sort first by weight, then by title.

 */

function ctools_plugin_sort($a, $b) {

  if (is_object($a)) {

    $a = (array) $a;

  }

  if (is_object($b)) {

    $b = (array) $b;

  }

  if (empty($a['weight'])) {

    $a['weight'] = 0;

  }

  if (empty($b['weight'])) {

    $b['weight'] = 0;

  }

  if ($a['weight'] == $b['weight']) {

    return strnatcmp(strtolower($a['title']), strtolower($b['title']));

  }

  return ($a['weight'] < $b['weight']) ? -1 : 1;

}