<?php

/**

 * @file

 * API for loading and interacting with Drupal modules.

 */

/**

 * Loads all the modules that have been enabled in the system table.

 *

 * @param $bootstrap

 *   Whether to load only the reduced set of modules loaded in "bootstrap mode"

 *   for cached pages. See bootstrap.inc.

 *

 * @return

 *   If $bootstrap is NULL, return a boolean indicating whether all modules

 *   have been loaded.

 */

function module_load_all($bootstrap = FALSE) {

  static $has_run = FALSE;

  if (isset($bootstrap)) {

    foreach (module_list(TRUE, $bootstrap) as $module) {

      drupal_load('module', $module);

    }

    // $has_run will be TRUE if $bootstrap is FALSE.

    $has_run = !$bootstrap;

  }

  return $has_run;

}

/**

 * Returns a list of currently active modules.

 *

 * Usually, this returns a list of all enabled modules. When called early on in

 * the bootstrap, it will return a list of vital modules only (those needed to

 * generate cached pages).

 *

 * All parameters to this function are optional and should generally not be

 * changed from their defaults.

 *

 * @param $refresh

 *   (optional) Whether to force the module list to be regenerated (such as

 *   after the administrator has changed the system settings). Defaults to

 *   FALSE.

 * @param $bootstrap_refresh

 *   (optional) When $refresh is TRUE, setting $bootstrap_refresh to TRUE forces

 *   the module list to be regenerated using the reduced set of modules loaded

 *   in "bootstrap mode" for cached pages. Otherwise, setting $refresh to TRUE

 *   generates the complete list of enabled modules.

 * @param $sort

 *   (optional) By default, modules are ordered by weight and module name. Set

 *   this option to TRUE to return a module list ordered only by module name.

 * @param $fixed_list

 *   (optional) If an array of module names is provided, this will override the

 *   module list with the given set of modules. This will persist until the next

 *   call with $refresh set to TRUE or with a new $fixed_list passed in. This

 *   parameter is primarily intended for internal use (e.g., in install.php and

 *   update.php).

 *

 * @return

 *   An associative array whose keys and values are the names of the modules in

 *   the list.

 */

function module_list($refresh = FALSE, $bootstrap_refresh = FALSE, $sort = FALSE, $fixed_list = NULL) {

  static $list = array(), $sorted_list;

  if (empty($list) || $refresh || $fixed_list) {

    $list = array();

    $sorted_list = NULL;

    if ($fixed_list) {

      foreach ($fixed_list as $name => $module) {

        drupal_get_filename('module', $name, $module['filename']);

        $list[$name] = $name;

      }

    }

    else {

      if ($refresh) {

        // For the $refresh case, make sure that system_list() returns fresh

        // data.

        drupal_static_reset('system_list');

      }

      if ($bootstrap_refresh) {

        $list = system_list('bootstrap');

      }

      else {

        // Not using drupal_map_assoc() here as that requires common.inc.

        $list = array_keys(system_list('module_enabled'));

        $list = (!empty($list) ? array_combine($list, $list) : array());

      }

    }

  }

  if ($sort) {

    if (!isset($sorted_list)) {

      $sorted_list = $list;

      ksort($sorted_list);

    }

    return $sorted_list;

  }

  return $list;

}

/**

 * Builds a list of bootstrap modules and enabled modules and themes.

 *

 * @param $type

 *   The type of list to return:

 *   - module_enabled: All enabled modules.

 *   - bootstrap: All enabled modules required for bootstrap.

 *   - theme: All themes.

 *

 * @return

 *   An associative array of modules or themes, keyed by name. For $type

 *   'bootstrap', the array values equal the keys. For $type 'module_enabled'

 *   or 'theme', the array values are objects representing the respective

 *   database row, with the 'info' property already unserialized.

 *

 * @see module_list()

 * @see list_themes()

 */

function system_list($type) {

  $lists = &drupal_static(__FUNCTION__);

  // For bootstrap modules, attempt to fetch the list from cache if possible.

  // if not fetch only the required information to fire bootstrap hooks

  // in case we are going to serve the page from cache.

  if ($type == 'bootstrap') {

    if (isset($lists['bootstrap'])) {

      return $lists['bootstrap'];

    }

    if ($cached = cache_get('bootstrap_modules', 'cache_bootstrap')) {

      $bootstrap_list = $cached->data;

    }

    else {

      $bootstrap_list = db_query("SELECT name, filename FROM {system} WHERE status = 1 AND bootstrap = 1 AND type = 'module' ORDER BY weight ASC, name ASC")->fetchAllAssoc('name');

      cache_set('bootstrap_modules', $bootstrap_list, 'cache_bootstrap');

    }

    // To avoid a separate database lookup for the filepath, prime the

    // drupal_get_filename() static cache for bootstrap modules only.

    // The rest is stored separately to keep the bootstrap module cache small.

    foreach ($bootstrap_list as $module) {

      drupal_get_filename('module', $module->name, $module->filename);

    }

    // We only return the module names here since module_list() doesn't need

    // the filename itself.

    $lists['bootstrap'] = array_keys($bootstrap_list);

  }

  // Otherwise build the list for enabled modules and themes.

  elseif (!isset($lists['module_enabled'])) {

    if ($cached = cache_get('system_list', 'cache_bootstrap')) {

      $lists = $cached->data;

    }

    else {

      $lists = array(

        'module_enabled' => array(),

        'theme' => array(),

        'filepaths' => array(),

      );

      // The module name (rather than the filename) is used as the fallback

      // weighting in order to guarantee consistent behavior across different

      // Drupal installations, which might have modules installed in different

      // locations in the file system. The ordering here must also be

      // consistent with the one used in module_implements().

      $result = db_query("SELECT * FROM {system} WHERE type = 'theme' OR (type = 'module' AND status = 1) ORDER BY weight ASC, name ASC");

      foreach ($result as $record) {

        $record->info = unserialize($record->info);

        // Build a list of all enabled modules.

        if ($record->type == 'module') {

          $lists['module_enabled'][$record->name] = $record;

        }

        // Build a list of themes.

        if ($record->type == 'theme') {

          $lists['theme'][$record->name] = $record;

        }

        // Build a list of filenames so drupal_get_filename can use it.

        if ($record->status) {

          $lists['filepaths'][] = array('type' => $record->type, 'name' => $record->name, 'filepath' => $record->filename);

        }

      }

      foreach ($lists['theme'] as $key => $theme) {

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

          // Make a list of the theme's base themes.

          require_once DRUPAL_ROOT . '/includes/theme.inc';

          $lists['theme'][$key]->base_themes = drupal_find_base_themes($lists['theme'], $key);

          // Don't proceed if there was a problem with the root base theme.

          if (!current($lists['theme'][$key]->base_themes)) {

            continue;

          }

          // Determine the root base theme.

          $base_key = key($lists['theme'][$key]->base_themes);

          // Add to the list of sub-themes for each of the theme's base themes.

          foreach (array_keys($lists['theme'][$key]->base_themes) as $base_theme) {

            $lists['theme'][$base_theme]->sub_themes[$key] = $lists['theme'][$key]->info['name'];

          }

          // Add the base theme's theme engine info.

          $lists['theme'][$key]->info['engine'] = isset($lists['theme'][$base_key]->info['engine']) ? $lists['theme'][$base_key]->info['engine'] : 'theme';

        }

        else {

          // A plain theme is its own engine.

          $base_key = $key;

          if (!isset($lists['theme'][$key]->info['engine'])) {

            $lists['theme'][$key]->info['engine'] = 'theme';

          }

        }

        // Set the theme engine prefix.

        $lists['theme'][$key]->prefix = ($lists['theme'][$key]->info['engine'] == 'theme') ? $base_key : $lists['theme'][$key]->info['engine'];

      }

      cache_set('system_list', $lists, 'cache_bootstrap');

    }

    // To avoid a separate database lookup for the filepath, prime the

    // drupal_get_filename() static cache with all enabled modules and themes.

    foreach ($lists['filepaths'] as $item) {

      drupal_get_filename($item['type'], $item['name'], $item['filepath']);

    }

  }

  return $lists[$type];

}

/**

 * Resets all system_list() caches.

 */

function system_list_reset() {

  drupal_static_reset('system_list');

  drupal_static_reset('system_rebuild_module_data');

  drupal_static_reset('list_themes');

  cache_clear_all('bootstrap_modules', 'cache_bootstrap');

  cache_clear_all('system_list', 'cache_bootstrap');

  // Clean up the bootstrap file scan cache.

  drupal_static_reset('_drupal_file_scan_cache');

  cache_clear_all('_drupal_file_scan_cache', 'cache_bootstrap');

}

/**

 * Determines which modules require and are required by each module.

 *

 * @param $files

 *   The array of filesystem objects used to rebuild the cache.

 *

 * @return

 *   The same array with the new keys for each module:

 *   - requires: An array with the keys being the modules that this module

 *     requires.

 *   - required_by: An array with the keys being the modules that will not work

 *     without this module.

 */

function _module_build_dependencies($files) {

  require_once DRUPAL_ROOT . '/includes/graph.inc';

  foreach ($files as $filename => $file) {

    $graph[$file->name]['edges'] = array();

    if (isset($file->info['dependencies']) && is_array($file->info['dependencies'])) {

      foreach ($file->info['dependencies'] as $dependency) {

        $dependency_data = drupal_parse_dependency($dependency);

        $graph[$file->name]['edges'][$dependency_data['name']] = $dependency_data;

      }

    }

  }

  drupal_depth_first_search($graph);

  foreach ($graph as $module => $data) {

    $files[$module]->required_by = isset($data['reverse_paths']) ? $data['reverse_paths'] : array();

    $files[$module]->requires = isset($data['paths']) ? $data['paths'] : array();

    $files[$module]->sort = $data['weight'];

  }

  return $files;

}

/**

 * Determines whether a given module exists.

 *

 * @param string $module

 *   The name of the module (without the .module extension).

 *

 * @return bool

 *   TRUE if the module is both installed and enabled, FALSE otherwise.

 */

function module_exists($module) {

  $list = module_list();

  return isset($list[$module]);

}

/**

 * Loads a module's installation hooks.

 *

 * @param $module

 *   The name of the module (without the .module extension).

 *

 * @return

 *   The name of the module's install file, if successful; FALSE otherwise.

 */

function module_load_install($module) {

  // Make sure the installation API is available

  include_once DRUPAL_ROOT . '/includes/install.inc';

  return module_load_include('install', $module);

}

/**

 * Loads a module include file.

 *

 * Examples:

 * @code

 *   // Load node.admin.inc from the node module.

 *   module_load_include('inc', 'node', 'node.admin');

 *   // Load content_types.inc from the node module.

 *   module_load_include('inc', 'node', 'content_types');

 * @endcode

 *

 * Do not use this function to load an install file, use module_load_install()

 * instead. Do not use this function in a global context since it requires

 * Drupal to be fully bootstrapped, use require_once DRUPAL_ROOT . '/path/file'

 * instead.

 *

 * @param $type

 *   The include file's type (file extension).

 * @param $module

 *   The module to which the include file belongs.

 * @param $name

 *   (optional) The base file name (without the $type extension). If omitted,

 *   $module is used; i.e., resulting in "$module.$type" by default.

 *

 * @return

 *   The name of the included file, if successful; FALSE otherwise.

 */

function module_load_include($type, $module, $name = NULL) {

  static $files = array();

  if (!isset($name)) {

    $name = $module;

  }

  $key = $type . ':' . $module . ':' . $name;

  if (isset($files[$key])) {

    return $files[$key];

  }

  if (function_exists('drupal_get_path')) {

    $file = DRUPAL_ROOT . '/' . drupal_get_path('module', $module) . "/$name.$type";

    if (is_file($file)) {

      require_once $file;

      $files[$key] = $file;

      return $file;

    }

    else {

      $files[$key] = FALSE;

    }

  }

  return FALSE;

}

/**

 * Loads an include file for each module enabled in the {system} table.

 */

function module_load_all_includes($type, $name = NULL) {

  $modules = module_list();

  foreach ($modules as $module) {

    module_load_include($type, $module, $name);

  }

}

/**

 * Enables or installs a given list of modules.

 *

 * Definitions:

 * - "Enabling" is the process of activating a module for use by Drupal.

 * - "Disabling" is the process of deactivating a module.

 * - "Installing" is the process of enabling it for the first time or after it

 *   has been uninstalled.

 * - "Uninstalling" is the process of removing all traces of a module.

 *

 * Order of events:

 * - Gather and add module dependencies to $module_list (if applicable).

 * - For each module that is being enabled:

 *   - Install module schema and update system registries and caches.

 *   - If the module is being enabled for the first time or had been

 *     uninstalled, invoke hook_install() and add it to the list of installed

 *     modules.

 *   - Invoke hook_enable().

 * - Invoke hook_modules_installed().

 * - Invoke hook_modules_enabled().

 *

 * @param string[] $module_list

 *   An array of module names.

 * @param bool $enable_dependencies

 *   If TRUE, dependencies will automatically be added and enabled in the

 *   correct order. This incurs a significant performance cost, so use FALSE

 *   if you know $module_list is already complete and in the correct order.

 *

 * @return bool

 *   FALSE if one or more dependencies are missing, TRUE otherwise.

 *

 * @see hook_install()

 * @see hook_enable()

 * @see hook_modules_installed()

 * @see hook_modules_enabled()

 * @see module_disable()

 * @see drupal_uninstall_modules()

 */

function module_enable($module_list, $enable_dependencies = TRUE) {

  if ($enable_dependencies) {

    // Get all module data so we can find dependencies and sort.

    $module_data = system_rebuild_module_data();

    // Create an associative array with weights as values.

    $module_list = array_flip(array_values($module_list));

    while (list($module) = each($module_list)) {

      if (!isset($module_data[$module])) {

        // This module is not found in the filesystem, abort.

        return FALSE;

      }

      if ($module_data[$module]->status) {

        // Skip already enabled modules.

        unset($module_list[$module]);

        continue;

      }

      $module_list[$module] = $module_data[$module]->sort;

      // Add dependencies to the list, with a placeholder weight.

      // The new modules will be processed as the while loop continues.

      foreach (array_keys($module_data[$module]->requires) as $dependency) {

        if (!isset($module_list[$dependency])) {

          $module_list[$dependency] = 0;

        }

      }

    }

    if (!$module_list) {

      // Nothing to do. All modules already enabled.

      return TRUE;

    }