module.inc
API for loading and interacting with Drupal modules.
File
drupal-6.x/includes/module.incView source
- <?php
-
- /**
- * @file
- * API for loading and interacting with Drupal modules.
- */
-
- /**
- * Load all the modules that have been enabled in the system table.
- */
- function module_load_all() {
- foreach (module_list(TRUE, FALSE) as $module) {
- drupal_load('module', $module);
- }
- }
-
- /**
- * Call a function repeatedly with each module in turn as an argument.
- */
- function module_iterate($function, $argument = '') {
- foreach (module_list() as $name) {
- $function($name, $argument);
- }
- }
-
- /**
- * Collect a list of all loaded modules. During the bootstrap, return only
- * vital modules. See bootstrap.inc
- *
- * @param $refresh
- * Whether to force the module list to be regenerated (such as after the
- * administrator has changed the system settings).
- * @param $bootstrap
- * Whether to return the reduced set of modules loaded in "bootstrap mode"
- * for cached pages. See bootstrap.inc.
- * @param $sort
- * By default, modules are ordered by weight and filename, settings this option
- * to TRUE, module list will be ordered by module name.
- * @param $fixed_list
- * (Optional) Override the module list with the given modules. Stays until the
- * next call with $refresh = TRUE.
- * @return
- * An associative array whose keys and values are the names of all loaded
- * modules.
- */
- function module_list($refresh = FALSE, $bootstrap = TRUE, $sort = FALSE, $fixed_list = NULL) {
- static $list, $sorted_list;
-
- if ($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] = $name;
- }
- }
- else {
- if ($bootstrap) {
- $result = db_query("SELECT name, filename, throttle FROM {system} WHERE type = 'module' AND status = 1 AND bootstrap = 1 ORDER BY weight ASC, filename ASC");
- }
- else {
- $result = db_query("SELECT name, filename, throttle FROM {system} WHERE type = 'module' AND status = 1 ORDER BY weight ASC, filename ASC");
- }
- while ($module = db_fetch_object($result)) {
- if (file_exists($module->filename)) {
- // Determine the current throttle status and see if the module should be
- // loaded based on server load. We have to directly access the throttle
- // variables, since throttle.module may not be loaded yet.
- $throttle = ($module->throttle && variable_get('throttle_level', 0) > 0);
- if (!$throttle) {
- drupal_get_filename('module', $module->name, $module->filename);
- $list[$module->name] = $module->name;
- }
- }
- }
- }
- }
- if ($sort) {
- if (!isset($sorted_list)) {
- $sorted_list = $list;
- ksort($sorted_list);
- }
- return $sorted_list;
- }
- return $list;
- }
-
- /**
- * Rebuild the database cache of module files.
- *
- * @return
- * The array of filesystem objects used to rebuild the cache.
- */
- function module_rebuild_cache() {
- $write_database = TRUE;
- // If lock not acquired, return $files data without writing to database.
- if (!lock_acquire('module_rebuild_cache')) {
- $write_database = FALSE;
- // Wait for the parallel thread to be done so we are more likely
- // to get updated and consistent data.
- lock_wait('module_rebuild_cache');
- }
- // Get current list of modules
- $files = drupal_system_listing('\.module$', 'modules', 'name', 0);
-
- // Extract current files from database.
- system_get_files_database($files, 'module');
-
- ksort($files);
-
- // Set defaults for module info
- $defaults = array(
- 'dependencies' => array(),
- 'dependents' => array(),
- 'description' => '',
- 'version' => NULL,
- 'php' => DRUPAL_MINIMUM_PHP,
- );
-
- foreach ($files as $filename => $file) {
- // Look for the info file.
- $file->info = drupal_parse_info_file(dirname($file->filename) .'/'. $file->name .'.info');
-
- // Skip modules that don't provide info.
- if (empty($file->info)) {
- unset($files[$filename]);
- continue;
- }
-
- // Invoke hook_system_info_alter() to give installed modules a chance to
- // modify the data in the .info files if necessary.
- drupal_alter('system_info', $files[$filename]->info, $files[$filename]);
-
- // Merge in defaults and save.
- $files[$filename]->info = $file->info + $defaults;
- }
-
- // If lock not acquired, return $files data without writing to database.
- if ($write_database) {
- foreach ($files as $filename => $file) {
- // Log the critical hooks implemented by this module.
- $bootstrap = 0;
- foreach (bootstrap_hooks() as $hook) {
- if (module_hook($file->name, $hook)) {
- $bootstrap = 1;
- break;
- }
- }
-
- // Update the contents of the system table:
- if (isset($file->status)) {
- db_query("UPDATE {system} SET info = '%s', name = '%s', filename = '%s', bootstrap = %d WHERE filename = '%s'", serialize($files[$filename]->info), $file->name, $file->filename, $bootstrap, $file->old_filename);
- }
- else {
- // This is a new module.
- $files[$filename]->status = 0;
- $files[$filename]->throttle = 0;
- db_query("INSERT INTO {system} (name, info, type, filename, status, throttle, bootstrap) VALUES ('%s', '%s', '%s', '%s', %d, %d, %d)", $file->name, serialize($files[$filename]->info), 'module', $file->filename, 0, 0, $bootstrap);
- }
- }
- lock_release('module_rebuild_cache');
- }
- $files = _module_build_dependencies($files);
- return $files;
- }
-
- /**
- * Find dependencies any level deep and fill in dependents information too.
- *
- * If module A depends on B which in turn depends on C then this function will
- * add C to the list of modules A depends on. This will be repeated until
- * module A has a list of all modules it depends on. If it depends on itself,
- * called a circular dependency, that's marked by adding a nonexistent module,
- * called -circular- to this list of modules. Because this does not exist,
- * it'll be impossible to switch module A on.
- *
- * Also we fill in a dependents array in $file->info. Using the names above,
- * the dependents array of module B lists A.
- *
- * @param $files
- * The array of filesystem objects used to rebuild the cache.
- * @return
- * The same array with dependencies and dependents added where applicable.
- */
- function _module_build_dependencies($files) {
- do {
- $new_dependency = FALSE;
- foreach ($files as $filename => $file) {
- // We will modify this object (module A, see doxygen for module A, B, C).
- $file = &$files[$filename];
- if (isset($file->info['dependencies']) && is_array($file->info['dependencies'])) {
- foreach ($file->info['dependencies'] as $dependency_name) {
- // This is a nonexistent module.
- if ($dependency_name == '-circular-' || !isset($files[$dependency_name])) {
- continue;
- }
- // $dependency_name is module B (again, see doxygen).
- $files[$dependency_name]->info['dependents'][$filename] = $filename;
- $dependency = $files[$dependency_name];
- if (isset($dependency->info['dependencies']) && is_array($dependency->info['dependencies'])) {
- // Let's find possible C modules.
- foreach ($dependency->info['dependencies'] as $candidate) {
- if (array_search($candidate, $file->info['dependencies']) === FALSE) {
- // Is this a circular dependency?
- if ($candidate == $filename) {
- // As a module name can not contain dashes, this makes
- // impossible to switch on the module.
- $candidate = '-circular-';
- // Do not display the message or add -circular- more than once.
- if (array_search($candidate, $file->info['dependencies']) !== FALSE) {
- continue;
- }
- drupal_set_message(t('%module is part of a circular dependency. This is not supported and you will not be able to switch it on.', array('%module' => $file->info['name'])), 'error');
- }
- else {
- // We added a new dependency to module A. The next loop will
- // be able to use this as "B module" thus finding even
- // deeper dependencies.
- $new_dependency = TRUE;
- }
- $file->info['dependencies'][] = $candidate;
- }
- }
- }
- }
- }
- // Don't forget to break the reference.
- unset($file);
- }
- } while ($new_dependency);
- 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) {
- $list = module_list();
- return array_key_exists($module, $list);
- }
-
- /**
- * Load a module's installation hooks.
- */
- function module_load_install($module) {
- // Make sure the installation API is available
- include_once './includes/install.inc';
-
- 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.
- *
- * @param $type
- * The include file's type (file extension).
- * @param $module
- * The module to which the include file belongs.
- * @param $name
- * Optionally, specify the base file name (without the $type extension).
- * If not set, $module is used.
- */
- function module_load_include($type, $module, $name = NULL) {
- if (empty($name)) {
- $name = $module;
- }
-
- $file = './'. drupal_get_path('module', $module) ."/$name.$type";
-
- if (is_file($file)) {
- require_once $file;
- }
- else {
- return FALSE;
- }
- }
-
- /**
- * Load an include file for each of the modules that have been enabled in
- * the system table.
- */
- function module_load_all_includes($type, $name = NULL) {
- $modules = module_list();
- foreach ($modules as $module) {
- module_load_include($type, $module, $name);
- }
- }
-
- /**
- * Enable a given list of modules.
- *
- * @param $module_list
- * An array of module names.
- */
- function module_enable($module_list) {
- $invoke_modules = array();
- foreach ($module_list as $module) {
- $existing = db_fetch_object(db_query("SELECT status FROM {system} WHERE type = '%s' AND name = '%s'", 'module', $module));
- if ($existing->status == 0) {
- module_load_install($module);
- db_query("UPDATE {system} SET status = %d, throttle = %d WHERE type = '%s' AND name = '%s'", 1, 0, 'module', $module);
- drupal_load('module', $module);
- $invoke_modules[] = $module;
- }
- }
-
- if (!empty($invoke_modules)) {
- // Refresh the module list to include the new enabled module.
- module_list(TRUE, FALSE);
- // Force to regenerate the stored list of hook implementations.
- module_implements('', FALSE, TRUE);
- }
-
- foreach ($invoke_modules as $module) {
- module_invoke($module, 'enable');
- // Check if node_access table needs rebuilding.
- // We check for the existence of node_access_needs_rebuild() since
- // at install time, module_enable() could be called while node.module
- // is not enabled yet.
- if (function_exists('node_access_needs_rebuild') && !node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
- node_access_needs_rebuild(TRUE);
- }
- }
- }
-
- /**
- * Disable a given set of modules.
- *
- * @param $module_list
- * An array of module names.
- */
- function module_disable($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_query("UPDATE {system} SET status = %d, throttle = %d WHERE type = '%s' AND name = '%s'", 0, 0, 'module', $module);
- $invoke_modules[] = $module;
- }
- }
-
- if (!empty($invoke_modules)) {
- // Refresh the module list to exclude the disabled modules.
- module_list(TRUE, FALSE);
- // Force to regenerate the stored list of hook implementations.
- module_implements('', FALSE, TRUE);
- }
-
- // 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().
- */
-
- /**
- * 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, $hook) {
- return function_exists($module .'_'. $hook);
- }
-
- /**
- * 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.
- * @param $refresh
- * For internal use only: Whether to force the stored list of hook
- * implementations to be regenerated (such as after enabling a new module,
- * before processing hook_enable).
- * @return
- * An array with the names of the modules which are implementing this hook.
- */
- function module_implements($hook, $sort = FALSE, $refresh = FALSE) {
- static $implementations;
-
- if ($refresh) {
- $implementations = array();
- return;
- }
-
- if (!isset($implementations[$hook])) {
- $implementations[$hook] = array();
- $list = module_list(FALSE, TRUE, $sort);
- foreach ($list as $module) {
- if (module_hook($module, $hook)) {
- $implementations[$hook][] = $module;
- }
- }
- }
-
- // The explicit cast forces a copy to be made. This is needed because
- // $implementations[$hook] is only a reference to an element of
- // $implementations and if there are nested foreaches (due to nested node
- // API calls, for example), they would both manipulate the same array's
- // references, which causes some modules' hooks not to be called.
- // See also http://www.zend.com/zend/art/ref-count.php.
- return (array)$implementations[$hook];
- }
-
- /**
- * 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() {
- $args = func_get_args();
- $module = $args[0];
- $hook = $args[1];
- unset($args[0], $args[1]);
- $function = $module .'_'. $hook;
- if (module_hook($module, $hook)) {
- return call_user_func_array($function, $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() {
- $args = func_get_args();
- $hook = $args[0];
- unset($args[0]);
- $return = array();
- foreach (module_implements($hook) as $module) {
- $function = $module .'_'. $hook;
- $result = call_user_func_array($function, $args);
- if (isset($result) && is_array($result)) {
- $return = array_merge_recursive($return, $result);
- }
- else if (isset($result)) {
- $return[] = $result;
- }
- }
-
- return $return;
- }
-
- /**
- * @} End of "defgroup hooks".
- */
-
- /**
- * Array of modules required by core.
- */
- function drupal_required_modules() {
- return array('block', 'filter', 'node', 'system', 'user');
- }