<?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));
// The array is iterated over manually (instead of using a foreach) because
// modules may be added to the list within the loop and we need to process
// them.
while ($module = key($module_list)) {
next($module_list);
if (!isset($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', $module)
->execute();
// Refresh the module list to include it.
system_list_reset();
module_list(TRUE);
module_implements('', FALSE, TRUE);
_system_update_bootstrap_status();
// Update the registry to include it.
registry_update();
// Refresh the schema to include it.
drupal_get_schema(NULL, TRUE);
// Update the theme registry to include it.
drupal_theme_rebuild();
// Clear entity cache.
entity_info_cache_clear();
// Now install the module if necessary.
if (drupal_get_installed_schema_version($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' => $module), WATCHDOG_INFO);
}
// Enable the module.
module_invoke($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;
}
/**
* Disables a given set of modules.
*
* @param string[] $module_list
* An array of module names.
* @param bool $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 $module_list is already complete and in the correct order.
*
* @see drupal_uninstall_modules()
* @see module_enable()
*/
function module_disable($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));
$profile = drupal_get_profile();
// The array is iterated over manually (instead of using a foreach) because
// modules may be added to the list within the loop and we need to process
// them.
while ($module = key($module_list)) {
next($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('', FALSE, TRUE);
entity_info_cache_clear();
// 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();
// Update the theme registry to remove the newly-disabled module.
drupal_theme_rebuild();
}
// 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 themeable
* @see callbacks
*/
/**
* @defgroup callbacks Callbacks
* @{
* Callback function signatures.
*
* Drupal's API sometimes uses callback functions to allow you to define how
* some type of processing happens. A callback is a function with a defined
* signature, which you define in a module. Then you pass the function name as
* a parameter to a Drupal API function or return it as part of a hook
* implementation return value, and your function is called at an appropriate
* time. For instance, when setting up batch processing you might need to
* provide a callback function for each processing step and/or a callback for
* when processing is finished; you would do that by defining these functions
* and passing their names into the batch setup function.
*
* Callback function signatures, like hook definitions, are described by
* creating and documenting dummy functions in a *.api.php file; normally, the
* dummy callback function's name should start with "callback_", and you should
* document the parameters and return value and provide a sample function body.
* Then your API documentation can refer to this callback function in its
* documentation. A user of your API can usually name their callback function
* anything they want, although a standard name would be to replace "callback_"
* with the module name.
*
* @see hooks
* @see themeable
*
* @}
*/
/**
* Determines 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;
}
/**
* Determines which modules are implementing a hook.
*
* Lazy-loaded include files specified with "group" via hook_hook_info() or
* hook_module_implements_alter() will be automatically included by this
* function when necessary.
*
* @param string $hook
* The name of the hook (e.g. "help" or "menu").
* @param bool $sort
* By default, modules are ordered by weight and filename, settings this option
* to TRUE, module list will be ordered by module name.
* @param bool $reset
* For internal use only: Whether to force the stored list of hook
* implementations to be regenerated (such as after enabling a new module,
* before processing hook_enable).
*
* @return
* An array with the names of the modules which are implementing this hook.
*
* @see module_implements_write_cache()
*/
function module_implements($hook, $sort = FALSE, $reset = 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__);
$drupal_static_fast['verified'] = &drupal_static(__FUNCTION__ . ':verified');
}
$implementations = &$drupal_static_fast['implementations'];
$verified = &$drupal_static_fast['verified'];
// 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.
if ($reset) {
$implementations = array();
$verified = array();
cache_set('module_implements', array(), 'cache_bootstrap');
drupal_static_reset('module_hook_info');
drupal_static_reset('drupal_alter');
cache_clear_all('hook_info', 'cache_bootstrap');
cache_clear_all('system_cache_tables', 'cache');
return;
}
// Fetch implementations from cache.
// This happens on the first call to module_implements(*, *, FALSE) during a
// request, but also when $implementations have been reset, e.g. after
// module_enable().
if (empty($implementations)) {
$implementations = cache_get('module_implements', 'cache_bootstrap');
if ($implementations === FALSE) {
$implementations = array();
}
else {
$implementations = $implementations->data;
}
// Forget all previously "verified" hooks, in case that $implementations
// were cleared via drupal_static_reset('module_implements') instead of
// module_implements(*, *, TRUE).
$verified = array();
}
if (!isset($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;
// Discover implementations for this hook.
$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') {
// Remember the implementations before hook_module_implements_alter().
$implementations_before = $implementations[$hook];
drupal_alter('module_implements', $implementations[$hook], $hook);
// Verify implementations that were added or modified.
foreach (array_diff_assoc($implementations[$hook], $implementations_before) as $module => $group) {
// If drupal_alter('module_implements') changed or added a $group, the
// respective file needs to be included.
if ($group) {
module_load_include('inc', $module, "$module.$group");
}
// If a new implementation was added, verify that the function exists.
if (!function_exists($module . '_' . $hook)) {
unset($implementations[$hook][$module]);
}
}
}
// Implementations for this hook are now "verified".
$verified[$hook] = TRUE;
}
elseif (!isset($verified[$hook])) {
// Implementations for this hook were in the cache, but they are not
// "verified" yet.
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;
}
}
$verified[$hook] = TRUE;
}
return array_keys($implementations[$hook]);
}
/**
* Retrieves a list of hooks that are declared through hook_hook_info().
*
* @return
* An associative array whose keys are hook names and whose values are an
* associative array containing a group name. The structure of the array
* is the same as the return value of hook_hook_info().
*
* @see hook_hook_info()
*/
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();
$cache = cache_get('hook_info', 'cache_bootstrap');
if ($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_set('hook_info', $hook_info, 'cache_bootstrap');
}
else {
$hook_info = $cache->data;
}
}
return $hook_info;
}
/**
* Writes the hook implementation cache.
*
* @see module_implements()
*/
function module_implements_write_cache() {
// The list of implementations includes vital modules only before full
// bootstrap, so do not write cache if we are not fully bootstrapped yet.
if (drupal_get_bootstrap_phase() != DRUPAL_BOOTSTRAP_FULL) {
return;
}
$implementations = &drupal_static('module_implements');
if (isset($implementations['#write_cache'])) {
unset($implementations['#write_cache']);
cache_set('module_implements', $implementations, 'cache_bootstrap');
}
}
/**
* Invokes a hook in a particular module.
*
* All arguments are passed by value. Use drupal_alter() if you need to pass
* arguments by reference.
*
* @param $module
* The name of the module (without the .module extension).
* @param $hook
* The name of the hook to invoke.
* @param ...
* Arguments to pass to the hook implementation.
*
* @return
* The return value of the hook implementation.
*
* @see drupal_alter()
*/
function module_invoke($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);
}
}
/**
* Invokes a hook in all enabled modules that implement it.
*
* All arguments are passed by value. Use drupal_alter() if you need to pass
* arguments by reference.
*
* @param $hook
* The name of the hook to invoke.
* @param ...
* Arguments to pass to the hook.
*
* @return
* An array of return values of the hook implementations. If modules return
* arrays from their implementations, those are merged into one array
* recursively. Note: integer keys in arrays will be lost, as the merge is
* done using array_merge_recursive().
*
* @see drupal_alter()
*/
function module_invoke_all($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".
*/
/**
* Returns an 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 installation 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;
}
/**
* Passes alterable variables to specific hook_TYPE_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 (a third is supported for
* legacy reasons, but should not be used in new code). 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.
* @param $context3
* (optional) An additional variable that is passed by reference. This
* parameter is deprecated and will not exist in Drupal 8; consequently, it
* should not be used for new Drupal 7 code either. It is here only for
* backwards compatibility with older code that passed additional arguments
* to drupal_alter().
*/
function drupal_alter($type, &$data, &$context1 = NULL, &$context2 = NULL, &$context3 = 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 $modules array in their
// appropriate order. module_implements() can only return ordered
// implementations of a single hook. To get the ordered implementations
// of multiple hooks, we mimic the module_implements() logic of first
// ordering by module_list(), and then calling
// drupal_alter('module_implements').
if (array_diff($extra_modules, $modules)) {
// Merge the arrays and order by module_list().
$modules = array_intersect(module_list(), array_merge($modules, $extra_modules));
// Since module_implements() already took care of loading the necessary
// include files, we can safely pass FALSE for the array values.
$implementations = array_fill_keys($modules, FALSE);
// Let modules adjust the order solely based on the primary hook. This
// ensures the same module order regardless of whether this if block
// runs. Calling drupal_alter() recursively in this way does not result
// in an infinite loop, because this call is for a single $type, so we
// won't end up in this code block again.
drupal_alter('module_implements', $implementations, $hook);
$modules = array_keys($implementations);
}
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, $context3);
}
}