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Diffstat (limited to 'core/includes/module.inc')
| -rw-r--r-- | core/includes/module.inc | 1007 |
1 files changed, 1007 insertions, 0 deletions
diff --git a/core/includes/module.inc b/core/includes/module.inc new file mode 100644 index 00000000000..e20e164a173 --- /dev/null +++ b/core/includes/module.inc @@ -0,0 +1,1007 @@ +<?php + +/** + * @file + * API for loading and interacting with Drupal modules. + */ + +/** + * Load 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; +} + +/** + * Build 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('bootstrap')->get('bootstrap_modules')) { + $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('bootstrap')->set('bootstrap_modules', $bootstrap_list); + } + // To avoid a separate database lookup for the filepath, prime the + // drupal_get_filename() static cache for bootstrap modules only. + // The rest is stored separately to keep the bootstrap module cache small. + foreach ($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('bootstrap')->get('system_list')) { + $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); + } + } + cache('bootstrap')->set('system_list', $lists); + } + // To avoid a separate database lookup for the filepath, prime the + // drupal_get_filename() static cache with all enabled modules and themes. + foreach ($lists['filepaths'] as $item) { + drupal_get_filename($item['type'], $item['name'], $item['filepath']); + } + } + + return $lists[$type]; +} + +/** + * Reset 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('bootstrap')->deleteMultiple(array('bootstrap_modules', 'system_list')); +} + +/** + * Find dependencies any level deep and fill in required by information too. + * + * @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; +} + +/** + * Determine whether a given module exists. + * + * @param $module + * The name of the module (without the .module extension). + * + * @return + * TRUE if the module is both installed and enabled. + */ +function module_exists($module) { + $list = module_list(); + return isset($list[$module]); +} + +/** + * Load 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); +} + +/** + * Load 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, $name = NULL) { + if (!isset($name)) { + $name = $module; + } + + if (function_exists('drupal_get_path')) { + $file = DRUPAL_ROOT . '/' . drupal_get_path('module', $module) . "/$name.$type"; + if (is_file($file)) { + require_once $file; + return $file; + } + } + return FALSE; +} + +/** + * Load an include file for each of the modules that have been enabled in + * the system table. + */ +function module_load_all_includes($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 $module_list + * An array of module names. + * @param $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 $module_list is already complete and in the correct order. + * + * @return + * FALSE if one or more dependencies are missing, TRUE otherwise. + * + * @see hook_install() + * @see hook_enable() + * @see hook_modules_installed() + * @see hook_modules_enabled() + */ +function module_enable($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 (!$module_list) { + // Nothing to do. All modules already enabled. + return TRUE; + } + + // Sort the module list by pre-calculated weights. + arsort($module_list); + $module_list = array_keys($module_list); + } + + // Required for module installation checks. + include_once DRUPAL_ROOT . '/includes/install.inc'; + + $modules_installed = array(); + $modules_enabled = array(); + foreach ($module_list as $module) { + // Only process modules that are not already enabled. + $existing = db_query("SELECT status FROM {system} WHERE type = :type AND name = :name", array( + ':type' => 'module', + ':name' => $module)) + ->fetchObject(); + if ($existing->status == 0) { + // Load the module's code. + drupal_load('module', $module); + module_load_install($module); + + // Update the database and module list to reflect the new module. This + // needs to be done first so that the module's hook implementations, + // hook_schema() in particular, can be called while it is being + // installed. + db_update('system') + ->fields(array('status' => 1)) + ->condition('type', 'module') + ->condition('name', $module) + ->execute(); + // Refresh the module list to include it. + system_list_reset(); + module_list(TRUE); + module_implements_reset(); + _system_update_bootstrap_status(); + // Update the registry to include it. + registry_update(); + // Refresh the schema to include it. + drupal_get_schema(NULL, TRUE); + + // Allow modules to react prior to the installation of a module. + module_invoke_all('modules_preinstall', array($module)); + + // Now install the module if necessary. + if (drupal_get_installed_schema_version($module, TRUE) == SCHEMA_UNINSTALLED) { + drupal_install_schema($module); + + // Set the schema version to the number of the last update provided + // by the module. + $versions = drupal_get_schema_versions($module); + $version = $versions ? max($versions) : SCHEMA_INSTALLED; + + // If the module has no current updates, but has some that were + // previously removed, set the version to the value of + // hook_update_last_removed(). + if ($last_removed = module_invoke($module, 'update_last_removed')) { + $version = max($version, $last_removed); + } + drupal_set_installed_schema_version($module, $version); + // Allow the module to perform install tasks. + module_invoke($module, 'install'); + // Record the fact that it was installed. + $modules_installed[] = $module; + watchdog('system', '%module module installed.', array('%module' => $module), WATCHDOG_INFO); + } + + // Allow modules to react prior to the enabling of a module. + module_invoke_all('modules_preenable', array($module)); + + // Enable the module. + module_invoke($module, 'enable'); + + // Record the fact that it was enabled. + $modules_enabled[] = $module; + watchdog('system', '%module module enabled.', array('%module' => $module), WATCHDOG_INFO); + } + } + + // If any modules were newly installed, invoke hook_modules_installed(). + if (!empty($modules_installed)) { + module_invoke_all('modules_installed', $modules_installed); + } + + // If any modules were newly enabled, invoke hook_modules_enabled(). + if (!empty($modules_enabled)) { + module_invoke_all('modules_enabled', $modules_enabled); + } + + return TRUE; +} + +/** + * Disable a given set of modules. + * + * @param $module_list + * An array of module names. + * @param $disable_dependents + * If TRUE, dependent modules will automatically be added and disabled in the + * correct order. This incurs a significant performance cost, so use FALSE + * if you know $module_list is already complete and in the correct order. + */ +function module_disable($module_list, $disable_dependents = TRUE) { + if ($disable_dependents) { + // Get all module data so we can find dependents and sort. + $module_data = system_rebuild_module_data(); + // Create an associative array with weights as values. + $module_list = array_flip(array_values($module_list)); + + $profile = drupal_get_profile(); + while (list($module) = each($module_list)) { + if (!isset($module_data[$module]) || !$module_data[$module]->status) { + // This module doesn't exist or is already disabled, skip it. + unset($module_list[$module]); + continue; + } + $module_list[$module] = $module_data[$module]->sort; + + // Add dependent modules to the list, with a placeholder weight. + // The new modules will be processed as the while loop continues. + foreach ($module_data[$module]->required_by as $dependent => $dependent_data) { + if (!isset($module_list[$dependent]) && $dependent != $profile) { + $module_list[$dependent] = 0; + } + } + } + + // Sort the module list by pre-calculated weights. + asort($module_list); + $module_list = array_keys($module_list); + } + + $invoke_modules = array(); + + foreach ($module_list as $module) { + if (module_exists($module)) { + // Check if node_access table needs rebuilding. + if (!node_access_needs_rebuild() && module_hook($module, 'node_grants')) { + node_access_needs_rebuild(TRUE); + } + + module_load_install($module); + module_invoke($module, 'disable'); + db_update('system') + ->fields(array('status' => 0)) + ->condition('type', 'module') + ->condition('name', $module) + ->execute(); + $invoke_modules[] = $module; + watchdog('system', '%module module disabled.', array('%module' => $module), WATCHDOG_INFO); + } + } + + if (!empty($invoke_modules)) { + // Refresh the module list to exclude the disabled modules. + system_list_reset(); + module_list(TRUE); + module_implements_reset(); + // Invoke hook_modules_disabled before disabling modules, + // so we can still call module hooks to get information. + module_invoke_all('modules_disabled', $invoke_modules); + // Update the registry to remove the newly-disabled module. + registry_update(); + _system_update_bootstrap_status(); + } + + // If there remains no more node_access module, rebuilding will be + // straightforward, we can do it right now. + if (node_access_needs_rebuild() && count(module_implements('node_grants')) == 0) { + node_access_rebuild(); + } +} + +/** + * @defgroup hooks Hooks + * @{ + * Allow modules to interact with the Drupal core. + * + * Drupal's module system is based on the concept of "hooks". A hook is a PHP + * function that is named foo_bar(), where "foo" is the name of the module + * (whose filename is thus foo.module) and "bar" is the name of the hook. Each + * hook has a defined set of parameters and a specified result type. + * + * To extend Drupal, a module need simply implement a hook. When Drupal wishes + * to allow intervention from modules, it determines which modules implement a + * hook and calls that hook in all enabled modules that implement it. + * + * The available hooks to implement are explained here in the Hooks section of + * the developer documentation. The string "hook" is used as a placeholder for + * the module name in the hook definitions. For example, if the module file is + * called example.module, then hook_help() as implemented by that module would + * be defined as example_help(). + * + * The example functions included are not part of the Drupal core, they are + * just models that you can modify. Only the hooks implemented within modules + * are executed when running Drupal. + * + * See also @link themeable the themeable group page. @endlink + */ + +/** + * Determine whether a module implements a hook. + * + * @param $module + * The name of the module (without the .module extension). + * @param $hook + * The name of the hook (e.g. "help" or "menu"). + * + * @return + * TRUE if the module is both installed and enabled, and the hook is + * implemented in that module. + */ +function module_hook($module, $hook) { + $function = $module . '_' . $hook; + if (function_exists($function)) { + return TRUE; + } + // If the hook implementation does not exist, check whether it may live in an + // optional include file registered via hook_hook_info(). + $hook_info = module_hook_info(); + if (isset($hook_info[$hook]['group'])) { + module_load_include('inc', $module, $module . '.' . $hook_info[$hook]['group']); + if (function_exists($function)) { + return TRUE; + } + } + return FALSE; +} + +/** + * Determine which modules are implementing a hook. + * + * @param $hook + * The name of the hook (e.g. "help" or "menu"). + * @param $sort + * By default, modules are ordered by weight and filename, settings this option + * to TRUE, module list will be ordered by module name. + * + * @return + * An array with the names of the modules which are implementing this hook. + * + * @see module_implements_write_cache() + */ +function module_implements($hook, $sort = FALSE) { + // Use the advanced drupal_static() pattern, since this is called very often. + static $drupal_static_fast; + if (!isset($drupal_static_fast)) { + $drupal_static_fast['implementations'] = &drupal_static(__FUNCTION__); + } + $implementations = &$drupal_static_fast['implementations']; + + // Fetch implementations from cache. + if (empty($implementations)) { + $implementations = cache('bootstrap')->get('module_implements'); + if ($implementations === FALSE) { + $implementations = array(); + } + else { + $implementations = $implementations->data; + } + } + + if (!isset($implementations[$hook])) { + // The hook is not cached, so ensure that whether or not it has + // implementations, that the cache is updated at the end of the request. + $implementations['#write_cache'] = TRUE; + $hook_info = module_hook_info(); + $implementations[$hook] = array(); + $list = module_list(FALSE, FALSE, $sort); + foreach ($list as $module) { + $include_file = isset($hook_info[$hook]['group']) && module_load_include('inc', $module, $module . '.' . $hook_info[$hook]['group']); + // Since module_hook() may needlessly try to load the include file again, + // function_exists() is used directly here. + if (function_exists($module . '_' . $hook)) { + $implementations[$hook][$module] = $include_file ? $hook_info[$hook]['group'] : FALSE; + } + } + // Allow modules to change the weight of specific implementations but avoid + // an infinite loop. + if ($hook != 'module_implements_alter') { + drupal_alter('module_implements', $implementations[$hook], $hook); + } + } + else { + foreach ($implementations[$hook] as $module => $group) { + // If this hook implementation is stored in a lazy-loaded file, so include + // that file first. + if ($group) { + module_load_include('inc', $module, "$module.$group"); + } + // It is possible that a module removed a hook implementation without the + // implementations cache being rebuilt yet, so we check whether the + // function exists on each request to avoid undefined function errors. + // Since module_hook() may needlessly try to load the include file again, + // function_exists() is used directly here. + if (!function_exists($module . '_' . $hook)) { + // Clear out the stale implementation from the cache and force a cache + // refresh to forget about no longer existing hook implementations. + unset($implementations[$hook][$module]); + $implementations['#write_cache'] = TRUE; + } + } + } + + return array_keys($implementations[$hook]); +} + +/** + * Regenerate the stored list of hook implementations. + */ +function module_implements_reset() { + // We maintain a persistent cache of hook implementations in addition to the + // static cache to avoid looping through every module and every hook on each + // request. Benchmarks show that the benefit of this caching outweighs the + // additional database hit even when using the default database caching + // backend and only a small number of modules are enabled. The cost of the + // cache_get() is more or less constant and reduced further when non-database + // caching backends are used, so there will be more significant gains when a + // large number of modules are installed or hooks invoked, since this can + // quickly lead to module_hook() being called several thousand times + // per request. + drupal_static_reset('module_implements'); + cache('bootstrap')->set('module_implements', array()); + drupal_static_reset('module_hook_info'); + drupal_static_reset('drupal_alter'); + cache('bootstrap')->delete('hook_info'); +} + +/** + * Retrieve a list of what hooks are explicitly declared. + */ +function module_hook_info() { + // This function is indirectly invoked from bootstrap_invoke_all(), in which + // case common.inc, subsystems, and modules are not loaded yet, so it does not + // make sense to support hook groups resp. lazy-loaded include files prior to + // full bootstrap. + if (drupal_bootstrap(NULL, FALSE) != DRUPAL_BOOTSTRAP_FULL) { + return array(); + } + $hook_info = &drupal_static(__FUNCTION__); + + if (!isset($hook_info)) { + $hook_info = array(); + $cache = cache('bootstrap')->get('hook_info'); + if ($cache === FALSE) { + // Rebuild the cache and save it. + // We can't use module_invoke_all() here or it would cause an infinite + // loop. + foreach (module_list() as $module) { + $function = $module . '_hook_info'; + if (function_exists($function)) { + $result = $function(); + if (isset($result) && is_array($result)) { + $hook_info = array_merge_recursive($hook_info, $result); + } + } + } + // We can't use drupal_alter() for the same reason as above. + foreach (module_list() as $module) { + $function = $module . '_hook_info_alter'; + if (function_exists($function)) { + $function($hook_info); + } + } + cache('bootstrap')->set('hook_info', $hook_info); + } + else { + $hook_info = $cache->data; + } + } + + return $hook_info; +} + +/** + * Writes the hook implementation cache. + * + * @see module_implements() + */ +function module_implements_write_cache() { + $implementations = &drupal_static('module_implements'); + // Check whether we need to write the cache. We do not want to cache hooks + // which are only invoked on HTTP POST requests since these do not need to be + // optimized as tightly, and not doing so keeps the cache entry smaller. + if (isset($implementations['#write_cache']) && ($_SERVER['REQUEST_METHOD'] == 'GET' || $_SERVER['REQUEST_METHOD'] == 'HEAD')) { + unset($implementations['#write_cache']); + cache('bootstrap')->set('module_implements', $implementations); + } +} + +/** + * Invoke a hook in a particular module. + * + * @param $module + * The name of the module (without the .module extension). + * @param $hook + * The name of the hook to invoke. + * @param ... + * Arguments to pass to the hook implementation. + * + * @return + * The return value of the hook implementation. + */ +function module_invoke($module, $hook) { + $args = func_get_args(); + // Remove $module and $hook from the arguments. + unset($args[0], $args[1]); + if (module_hook($module, $hook)) { + return call_user_func_array($module . '_' . $hook, $args); + } +} + +/** + * Invoke a hook in all enabled modules that implement it. + * + * @param $hook + * The name of the hook to invoke. + * @param ... + * Arguments to pass to the hook. + * + * @return + * An array of return values of the hook implementations. If modules return + * arrays from their implementations, those are merged into one array. + */ +function module_invoke_all($hook) { + $args = func_get_args(); + // Remove $hook from the arguments. + unset($args[0]); + $return = array(); + foreach (module_implements($hook) as $module) { + $function = $module . '_' . $hook; + if (function_exists($function)) { + $result = call_user_func_array($function, $args); + if (isset($result) && is_array($result)) { + $return = array_merge_recursive($return, $result); + } + elseif (isset($result)) { + $return[] = $result; + } + } + } + + return $return; +} + +/** + * @} End of "defgroup hooks". + */ + +/** + * Array of modules required by core. + */ +function drupal_required_modules() { + $files = drupal_system_listing('/^' . DRUPAL_PHP_FUNCTION_PATTERN . '\.info$/', 'modules', 'name', 0); + $required = array(); + + // An install profile is required and one must always be loaded. + $required[] = drupal_get_profile(); + + foreach ($files as $name => $file) { + $info = drupal_parse_info_file($file->uri); + if (!empty($info) && !empty($info['required']) && $info['required']) { + $required[] = $name; + } + } + + return $required; +} + +/** + * Hands off alterable variables to type-specific *_alter implementations. + * + * This dispatch function hands off the passed-in variables to type-specific + * hook_TYPE_alter() implementations in modules. It ensures a consistent + * interface for all altering operations. + * + * A maximum of 2 alterable arguments is supported. In case more arguments need + * to be passed and alterable, modules provide additional variables assigned by + * reference in the last $context argument: + * @code + * $context = array( + * 'alterable' => &$alterable, + * 'unalterable' => $unalterable, + * 'foo' => 'bar', + * ); + * drupal_alter('mymodule_data', $alterable1, $alterable2, $context); + * @endcode + * + * Note that objects are always passed by reference in PHP5. If it is absolutely + * required that no implementation alters a passed object in $context, then an + * object needs to be cloned: + * @code + * $context = array( + * 'unalterable_object' => clone $object, + * ); + * drupal_alter('mymodule_data', $data, $context); + * @endcode + * + * @param $type + * A string describing the type of the alterable $data. 'form', 'links', + * 'node_content', and so on are several examples. Alternatively can be an + * array, in which case hook_TYPE_alter() is invoked for each value in the + * array, ordered first by module, and then for each module, in the order of + * values in $type. For example, when Form API is using drupal_alter() to + * execute both hook_form_alter() and hook_form_FORM_ID_alter() + * implementations, it passes array('form', 'form_' . $form_id) for $type. + * @param $data + * The variable that will be passed to hook_TYPE_alter() implementations to be + * altered. The type of this variable depends on the value of the $type + * argument. For example, when altering a 'form', $data will be a structured + * array. When altering a 'profile', $data will be an object. + * @param $context1 + * (optional) An additional variable that is passed by reference. + * @param $context2 + * (optional) An additional variable that is passed by reference. If more + * context needs to be provided to implementations, then this should be an + * associative array as described above. + */ +function drupal_alter($type, &$data, &$context1 = NULL, &$context2 = NULL) { + // Use the advanced drupal_static() pattern, since this is called very often. + static $drupal_static_fast; + if (!isset($drupal_static_fast)) { + $drupal_static_fast['functions'] = &drupal_static(__FUNCTION__); + } + $functions = &$drupal_static_fast['functions']; + + // Most of the time, $type is passed as a string, so for performance, + // normalize it to that. When passed as an array, usually the first item in + // the array is a generic type, and additional items in the array are more + // specific variants of it, as in the case of array('form', 'form_FORM_ID'). + if (is_array($type)) { + $cid = implode(',', $type); + $extra_types = $type; + $type = array_shift($extra_types); + // Allow if statements in this function to use the faster isset() rather + // than !empty() both when $type is passed as a string, or as an array with + // one item. + if (empty($extra_types)) { + unset($extra_types); + } + } + else { + $cid = $type; + } + + // Some alter hooks are invoked many times per page request, so statically + // cache the list of functions to call, and on subsequent calls, iterate + // through them quickly. + if (!isset($functions[$cid])) { + $functions[$cid] = array(); + $hook = $type . '_alter'; + $modules = module_implements($hook); + if (!isset($extra_types)) { + // For the more common case of a single hook, we do not need to call + // function_exists(), since module_implements() returns only modules with + // implementations. + foreach ($modules as $module) { + $functions[$cid][] = $module . '_' . $hook; + } + } + else { + // For multiple hooks, we need $modules to contain every module that + // implements at least one of them. + $extra_modules = array(); + foreach ($extra_types as $extra_type) { + $extra_modules = array_merge($extra_modules, module_implements($extra_type . '_alter')); + } + // If any modules implement one of the extra hooks that do not implement + // the primary hook, we need to add them to the $modules array in their + // appropriate order. + if (array_diff($extra_modules, $modules)) { + // Order the modules by the order returned by module_list(). + $modules = array_intersect(module_list(), array_merge($modules, $extra_modules)); + } + foreach ($modules as $module) { + // Since $modules is a merged array, for any given module, we do not + // know whether it has any particular implementation, so we need a + // function_exists(). + $function = $module . '_' . $hook; + if (function_exists($function)) { + $functions[$cid][] = $function; + } + foreach ($extra_types as $extra_type) { + $function = $module . '_' . $extra_type . '_alter'; + if (function_exists($function)) { + $functions[$cid][] = $function; + } + } + } + } + // Allow the theme to alter variables after the theme system has been + // initialized. + global $theme, $base_theme_info; + if (isset($theme)) { + $theme_keys = array(); + foreach ($base_theme_info as $base) { + $theme_keys[] = $base->name; + } + $theme_keys[] = $theme; + foreach ($theme_keys as $theme_key) { + $function = $theme_key . '_' . $hook; + if (function_exists($function)) { + $functions[$cid][] = $function; + } + if (isset($extra_types)) { + foreach ($extra_types as $extra_type) { + $function = $theme_key . '_' . $extra_type . '_alter'; + if (function_exists($function)) { + $functions[$cid][] = $function; + } + } + } + } + } + } + + foreach ($functions[$cid] as $function) { + $function($data, $context1, $context2); + } +} + |