webmaster@1: <?php
webmaster@1: // $Id: module.inc,v 1.115 2007/12/27 12:31:05 goba Exp $
webmaster@1: 
webmaster@1: /**
webmaster@1:  * @file
webmaster@1:  * API for loading and interacting with Drupal modules.
webmaster@1:  */
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Load all the modules that have been enabled in the system table.
webmaster@1:  */
webmaster@1: function module_load_all() {
webmaster@1:   foreach (module_list(TRUE, FALSE) as $module) {
webmaster@1:     drupal_load('module', $module);
webmaster@1:   }
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Call a function repeatedly with each module in turn as an argument.
webmaster@1:  */
webmaster@1: function module_iterate($function, $argument = '') {
webmaster@1:   foreach (module_list() as $name) {
webmaster@1:     $function($name, $argument);
webmaster@1:   }
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Collect a list of all loaded modules. During the bootstrap, return only
webmaster@1:  * vital modules. See bootstrap.inc
webmaster@1:  *
webmaster@1:  * @param $refresh
webmaster@1:  *   Whether to force the module list to be regenerated (such as after the
webmaster@1:  *   administrator has changed the system settings).
webmaster@1:  * @param $bootstrap
webmaster@1:  *   Whether to return the reduced set of modules loaded in "bootstrap mode"
webmaster@1:  *   for cached pages. See bootstrap.inc.
webmaster@1:  * @param $sort
webmaster@1:  *   By default, modules are ordered by weight and filename, settings this option
webmaster@1:  *   to TRUE, module list will be ordered by module name.
webmaster@1:  * @param $fixed_list
webmaster@1:  *   (Optional) Override the module list with the given modules. Stays until the
webmaster@1:  *   next call with $refresh = TRUE.
webmaster@1:  * @return
webmaster@1:  *   An associative array whose keys and values are the names of all loaded
webmaster@1:  *   modules.
webmaster@1:  */
webmaster@1: function module_list($refresh = FALSE, $bootstrap = TRUE, $sort = FALSE, $fixed_list = NULL) {
webmaster@1:   static $list, $sorted_list;
webmaster@1: 
webmaster@1:   if ($refresh || $fixed_list) {
webmaster@1:     unset($sorted_list);
webmaster@1:     $list = array();
webmaster@1:     if ($fixed_list) {
webmaster@1:       foreach ($fixed_list as $name => $module) {
webmaster@1:         drupal_get_filename('module', $name, $module['filename']);
webmaster@1:         $list[$name] = $name;
webmaster@1:       }
webmaster@1:     }
webmaster@1:     else {
webmaster@1:       if ($bootstrap) {
webmaster@1:         $result = db_query("SELECT name, filename, throttle FROM {system} WHERE type = 'module' AND status = 1 AND bootstrap = 1 ORDER BY weight ASC, filename ASC");
webmaster@1:       }
webmaster@1:       else {
webmaster@1:         $result = db_query("SELECT name, filename, throttle FROM {system} WHERE type = 'module' AND status = 1 ORDER BY weight ASC, filename ASC");
webmaster@1:       }
webmaster@1:       while ($module = db_fetch_object($result)) {
webmaster@1:         if (file_exists($module->filename)) {
webmaster@1:           // Determine the current throttle status and see if the module should be
webmaster@1:           // loaded based on server load. We have to directly access the throttle
webmaster@1:           // variables, since throttle.module may not be loaded yet.
webmaster@1:           $throttle = ($module->throttle && variable_get('throttle_level', 0) > 0);
webmaster@1:           if (!$throttle) {
webmaster@1:             drupal_get_filename('module', $module->name, $module->filename);
webmaster@1:             $list[$module->name] = $module->name;
webmaster@1:           }
webmaster@1:         }
webmaster@1:       }
webmaster@1:     }
webmaster@1:   }
webmaster@1:   if ($sort) {
webmaster@1:     if (!isset($sorted_list)) {
webmaster@1:       $sorted_list = $list;
webmaster@1:       ksort($sorted_list);
webmaster@1:     }
webmaster@1:     return $sorted_list;
webmaster@1:   }
webmaster@1:   return $list;
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Rebuild the database cache of module files.
webmaster@1:  *
webmaster@1:  * @return
webmaster@1:  *   The array of filesystem objects used to rebuild the cache.
webmaster@1:  */
webmaster@1: function module_rebuild_cache() {
webmaster@1:   // Get current list of modules
webmaster@1:   $files = drupal_system_listing('\.module$', 'modules', 'name', 0);
webmaster@1: 
webmaster@1:   // Extract current files from database.
webmaster@1:   system_get_files_database($files, 'module');
webmaster@1: 
webmaster@1:   ksort($files);
webmaster@1: 
webmaster@1:   // Set defaults for module info
webmaster@1:   $defaults = array(
webmaster@1:     'dependencies' => array(),
webmaster@1:     'dependents' => array(),
webmaster@1:     'description' => '',
webmaster@1:     'version' => NULL,
webmaster@1:     'php' => DRUPAL_MINIMUM_PHP,
webmaster@1:   );
webmaster@1: 
webmaster@1:   foreach ($files as $filename => $file) {
webmaster@1:     // Look for the info file.
webmaster@1:     $file->info = drupal_parse_info_file(dirname($file->filename) .'/'. $file->name .'.info');
webmaster@1: 
webmaster@1:     // Skip modules that don't provide info.
webmaster@1:     if (empty($file->info)) {
webmaster@1:       unset($files[$filename]);
webmaster@1:       continue;
webmaster@1:     }
webmaster@1:     // Merge in defaults and save.
webmaster@1:     $files[$filename]->info = $file->info + $defaults;
webmaster@1: 
webmaster@1:     // Invoke hook_system_info_alter() to give installed modules a chance to
webmaster@1:     // modify the data in the .info files if necessary.
webmaster@1:     drupal_alter('system_info', $files[$filename]->info, $files[$filename]);
webmaster@1: 
webmaster@1:     // Log the critical hooks implemented by this module.
webmaster@1:     $bootstrap = 0;
webmaster@1:     foreach (bootstrap_hooks() as $hook) {
webmaster@1:       if (module_hook($file->name, $hook)) {
webmaster@1:         $bootstrap = 1;
webmaster@1:         break;
webmaster@1:       }
webmaster@1:     }
webmaster@1: 
webmaster@1:     // Update the contents of the system table:
webmaster@1:     if (isset($file->status) || (isset($file->old_filename) && $file->old_filename != $file->filename)) {
webmaster@1:       db_query("UPDATE {system} SET info = '%s', name = '%s', filename = '%s', bootstrap = %d WHERE filename = '%s'", serialize($files[$filename]->info), $file->name, $file->filename, $bootstrap, $file->old_filename);
webmaster@1:     }
webmaster@1:     else {
webmaster@1:       // This is a new module.
webmaster@1:       $files[$filename]->status = 0;
webmaster@1:       $files[$filename]->throttle = 0;
webmaster@1:       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);
webmaster@1:     }
webmaster@1:   }
webmaster@1:   $files = _module_build_dependencies($files);
webmaster@1:   return $files;
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Find dependencies any level deep and fill in dependents information too.
webmaster@1:  *
webmaster@1:  * If module A depends on B which in turn depends on C then this function will
webmaster@1:  * add C to the list of modules A depends on. This will be repeated until
webmaster@1:  * module A has a list of all modules it depends on. If it depends on itself,
webmaster@1:  * called a circular dependency, that's marked by adding a nonexistent module,
webmaster@1:  * called -circular- to this list of modules. Because this does not exist,
webmaster@1:  * it'll be impossible to switch module A on.
webmaster@1:  *
webmaster@1:  * Also we fill in a dependents array in $file->info. Using the names above,
webmaster@1:  * the dependents array of module B lists A.
webmaster@1:  *
webmaster@1:  * @param $files
webmaster@1:  *   The array of filesystem objects used to rebuild the cache.
webmaster@1:  * @return
webmaster@1:  *   The same array with dependencies and dependents added where applicable.
webmaster@1:  */
webmaster@1: function _module_build_dependencies($files) {
webmaster@1:   do {
webmaster@1:     $new_dependency = FALSE;
webmaster@1:     foreach ($files as $filename => $file) {
webmaster@1:       // We will modify this object (module A, see doxygen for module A, B, C).
webmaster@1:       $file = &$files[$filename];
webmaster@1:       if (isset($file->info['dependencies']) && is_array($file->info['dependencies'])) {
webmaster@1:         foreach ($file->info['dependencies'] as $dependency_name) {
webmaster@1:           // This is a nonexistent module.
webmaster@1:           if ($dependency_name == '-circular-' || !isset($files[$dependency_name])) {
webmaster@1:             continue;
webmaster@1:           }
webmaster@1:           // $dependency_name is module B (again, see doxygen).
webmaster@1:           $files[$dependency_name]->info['dependents'][$filename] = $filename;
webmaster@1:           $dependency = $files[$dependency_name];
webmaster@1:           if (isset($dependency->info['dependencies']) && is_array($dependency->info['dependencies'])) {
webmaster@1:             // Let's find possible C modules.
webmaster@1:             foreach ($dependency->info['dependencies'] as $candidate) {
webmaster@1:               if (array_search($candidate, $file->info['dependencies']) === FALSE) {
webmaster@1:                 // Is this a circular dependency?
webmaster@1:                 if ($candidate == $filename) {
webmaster@1:                   // As a module name can not contain dashes, this makes
webmaster@1:                   // impossible to switch on the module.
webmaster@1:                   $candidate = '-circular-';
webmaster@1:                   // Do not display the message or add -circular- more than once.
webmaster@1:                   if (array_search($candidate, $file->info['dependencies']) !== FALSE) {
webmaster@1:                     continue;
webmaster@1:                   }
webmaster@1:                   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');
webmaster@1:                 }
webmaster@1:                 else {
webmaster@1:                   // We added a new dependency to module A. The next loop will
webmaster@1:                   // be able to use this as "B module" thus finding even
webmaster@1:                   // deeper dependencies.
webmaster@1:                   $new_dependency = TRUE;
webmaster@1:                 }
webmaster@1:                 $file->info['dependencies'][] = $candidate;
webmaster@1:               }
webmaster@1:             }
webmaster@1:           }
webmaster@1:         }
webmaster@1:       }
webmaster@1:       // Don't forget to break the reference.
webmaster@1:       unset($file);
webmaster@1:     }
webmaster@1:   } while ($new_dependency);
webmaster@1:   return $files;
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Determine whether a given module exists.
webmaster@1:  *
webmaster@1:  * @param $module
webmaster@1:  *   The name of the module (without the .module extension).
webmaster@1:  * @return
webmaster@1:  *   TRUE if the module is both installed and enabled.
webmaster@1:  */
webmaster@1: function module_exists($module) {
webmaster@1:   $list = module_list();
webmaster@1:   return array_key_exists($module, $list);
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Load a module's installation hooks.
webmaster@1:  */
webmaster@1: function module_load_install($module) {
webmaster@1:   // Make sure the installation API is available
webmaster@1:   include_once './includes/install.inc';
webmaster@1: 
webmaster@1:   module_load_include('install', $module);
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Load a module include file.
webmaster@1:  *
webmaster@1:  * @param $type
webmaster@1:  *   The include file's type (file extension).
webmaster@1:  * @param $module
webmaster@1:  *   The module to which the include file belongs.
webmaster@1:  * @param $name
webmaster@1:  *   Optionally, specify the file name. If not set, the module's name is used.
webmaster@1:  */
webmaster@1: function module_load_include($type, $module, $name = NULL) {
webmaster@1:   if (empty($name)) {
webmaster@1:     $name = $module;
webmaster@1:   }
webmaster@1: 
webmaster@1:   $file = './'. drupal_get_path('module', $module) ."/$name.$type";
webmaster@1: 
webmaster@1:   if (is_file($file)) {
webmaster@1:     require_once $file;
webmaster@1:   }
webmaster@1:   else {
webmaster@1:     return FALSE;
webmaster@1:   }
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Load an include file for each of the modules that have been enabled in
webmaster@1:  * the system table.
webmaster@1:  */
webmaster@1: function module_load_all_includes($type, $name = NULL) {
webmaster@1:   $modules = module_list();
webmaster@1:   foreach ($modules as $module) {
webmaster@1:     module_load_include($type, $module, $name);
webmaster@1:   }
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Enable a given list of modules.
webmaster@1:  *
webmaster@1:  * @param $module_list
webmaster@1:  *   An array of module names.
webmaster@1:  */
webmaster@1: function module_enable($module_list) {
webmaster@1:   $invoke_modules = array();
webmaster@1:   foreach ($module_list as $module) {
webmaster@1:     $existing = db_fetch_object(db_query("SELECT status FROM {system} WHERE type = '%s' AND name = '%s'", 'module', $module));
webmaster@1:     if ($existing->status == 0) {
webmaster@1:       module_load_install($module);
webmaster@1:       db_query("UPDATE {system} SET status = %d, throttle = %d WHERE type = '%s' AND name = '%s'", 1, 0, 'module', $module);
webmaster@1:       drupal_load('module', $module);
webmaster@1:       $invoke_modules[] = $module;
webmaster@1:     }
webmaster@1:   }
webmaster@1: 
webmaster@1:   if (!empty($invoke_modules)) {
webmaster@1:     // Refresh the module list to include the new enabled module.
webmaster@1:     module_list(TRUE, FALSE);
webmaster@1:     // Force to regenerate the stored list of hook implementations.
webmaster@1:     module_implements('', FALSE, TRUE);
webmaster@1:   }
webmaster@1: 
webmaster@1:   foreach ($invoke_modules as $module) {
webmaster@1:     module_invoke($module, 'enable');
webmaster@1:     // Check if node_access table needs rebuilding.
webmaster@1:     // We check for the existence of node_access_needs_rebuild() since
webmaster@1:     // at install time, module_enable() could be called while node.module
webmaster@1:     // is not enabled yet.
webmaster@1:     if (function_exists('node_access_needs_rebuild') && !node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
webmaster@1:       node_access_needs_rebuild(TRUE);
webmaster@1:     }
webmaster@1:   }
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Disable a given set of modules.
webmaster@1:  *
webmaster@1:  * @param $module_list
webmaster@1:  *   An array of module names.
webmaster@1:  */
webmaster@1: function module_disable($module_list) {
webmaster@1:   $invoke_modules = array();
webmaster@1:   foreach ($module_list as $module) {
webmaster@1:     if (module_exists($module)) {
webmaster@1:       // Check if node_access table needs rebuilding.
webmaster@1:       if (!node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
webmaster@1:         node_access_needs_rebuild(TRUE);
webmaster@1:       }
webmaster@1: 
webmaster@1:       module_load_install($module);
webmaster@1:       module_invoke($module, 'disable');
webmaster@1:       db_query("UPDATE {system} SET status = %d, throttle = %d WHERE type = '%s' AND name = '%s'", 0, 0, 'module', $module);
webmaster@1:       $invoke_modules[] = $module;
webmaster@1:     }
webmaster@1:   }
webmaster@1: 
webmaster@1:   if (!empty($invoke_modules)) {
webmaster@1:     // Refresh the module list to exclude the disabled modules.
webmaster@1:     module_list(TRUE, FALSE);
webmaster@1:     // Force to regenerate the stored list of hook implementations.
webmaster@1:     module_implements('', FALSE, TRUE);
webmaster@1:   }
webmaster@1: 
webmaster@1:   // If there remains no more node_access module, rebuilding will be
webmaster@1:   // straightforward, we can do it right now.
webmaster@1:   if (node_access_needs_rebuild() && count(module_implements('node_grants')) == 0) {
webmaster@1:     node_access_rebuild();
webmaster@1:   }
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * @defgroup hooks Hooks
webmaster@1:  * @{
webmaster@1:  * Allow modules to interact with the Drupal core.
webmaster@1:  *
webmaster@1:  * Drupal's module system is based on the concept of "hooks". A hook is a PHP
webmaster@1:  * function that is named foo_bar(), where "foo" is the name of the module (whose
webmaster@1:  * filename is thus foo.module) and "bar" is the name of the hook. Each hook has
webmaster@1:  * a defined set of parameters and a specified result type.
webmaster@1:  *
webmaster@1:  * To extend Drupal, a module need simply implement a hook. When Drupal wishes to
webmaster@1:  * allow intervention from modules, it determines which modules implement a hook
webmaster@1:  * and call that hook in all enabled modules that implement it.
webmaster@1:  *
webmaster@1:  * The available hooks to implement are explained here in the Hooks section of
webmaster@1:  * the developer documentation. The string "hook" is used as a placeholder for
webmaster@1:  * the module name is the hook definitions. For example, if the module file is
webmaster@1:  * called example.module, then hook_help() as implemented by that module would be
webmaster@1:  * defined as example_help().
webmaster@1:  */
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Determine whether a module implements a hook.
webmaster@1:  *
webmaster@1:  * @param $module
webmaster@1:  *   The name of the module (without the .module extension).
webmaster@1:  * @param $hook
webmaster@1:  *   The name of the hook (e.g. "help" or "menu").
webmaster@1:  * @return
webmaster@1:  *   TRUE if the module is both installed and enabled, and the hook is
webmaster@1:  *   implemented in that module.
webmaster@1:  */
webmaster@1: function module_hook($module, $hook) {
webmaster@1:   return function_exists($module .'_'. $hook);
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Determine which modules are implementing a hook.
webmaster@1:  *
webmaster@1:  * @param $hook
webmaster@1:  *   The name of the hook (e.g. "help" or "menu").
webmaster@1:  * @param $sort
webmaster@1:  *   By default, modules are ordered by weight and filename, settings this option
webmaster@1:  *   to TRUE, module list will be ordered by module name.
webmaster@1:  * @param $refresh
webmaster@1:  *   For internal use only: Whether to force the stored list of hook
webmaster@1:  *   implementations to be regenerated (such as after enabling a new module,
webmaster@1:  *   before processing hook_enable).
webmaster@1:  * @return
webmaster@1:  *   An array with the names of the modules which are implementing this hook.
webmaster@1:  */
webmaster@1: function module_implements($hook, $sort = FALSE, $refresh = FALSE) {
webmaster@1:   static $implementations;
webmaster@1: 
webmaster@1:   if ($refresh) {
webmaster@1:     $implementations = array();
webmaster@1:     return;
webmaster@1:   }
webmaster@1: 
webmaster@1:   if (!isset($implementations[$hook])) {
webmaster@1:     $implementations[$hook] = array();
webmaster@1:     $list = module_list(FALSE, TRUE, $sort);
webmaster@1:     foreach ($list as $module) {
webmaster@1:       if (module_hook($module, $hook)) {
webmaster@1:         $implementations[$hook][] = $module;
webmaster@1:       }
webmaster@1:     }
webmaster@1:   }
webmaster@1: 
webmaster@1:   // The explicit cast forces a copy to be made. This is needed because
webmaster@1:   // $implementations[$hook] is only a reference to an element of
webmaster@1:   // $implementations and if there are nested foreaches (due to nested node
webmaster@1:   // API calls, for example), they would both manipulate the same array's
webmaster@1:   // references, which causes some modules' hooks not to be called.
webmaster@1:   // See also http://www.zend.com/zend/art/ref-count.php.
webmaster@1:   return (array)$implementations[$hook];
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Invoke a hook in a particular module.
webmaster@1:  *
webmaster@1:  * @param $module
webmaster@1:  *   The name of the module (without the .module extension).
webmaster@1:  * @param $hook
webmaster@1:  *   The name of the hook to invoke.
webmaster@1:  * @param ...
webmaster@1:  *   Arguments to pass to the hook implementation.
webmaster@1:  * @return
webmaster@1:  *   The return value of the hook implementation.
webmaster@1:  */
webmaster@1: function module_invoke() {
webmaster@1:   $args = func_get_args();
webmaster@1:   $module = $args[0];
webmaster@1:   $hook = $args[1];
webmaster@1:   unset($args[0], $args[1]);
webmaster@1:   $function = $module .'_'. $hook;
webmaster@1:   if (module_hook($module, $hook)) {
webmaster@1:     return call_user_func_array($function, $args);
webmaster@1:   }
webmaster@1: }
webmaster@1: /**
webmaster@1:  * Invoke a hook in all enabled modules that implement it.
webmaster@1:  *
webmaster@1:  * @param $hook
webmaster@1:  *   The name of the hook to invoke.
webmaster@1:  * @param ...
webmaster@1:  *   Arguments to pass to the hook.
webmaster@1:  * @return
webmaster@1:  *   An array of return values of the hook implementations. If modules return
webmaster@1:  *   arrays from their implementations, those are merged into one array.
webmaster@1:  */
webmaster@1: function module_invoke_all() {
webmaster@1:   $args = func_get_args();
webmaster@1:   $hook = $args[0];
webmaster@1:   unset($args[0]);
webmaster@1:   $return = array();
webmaster@1:   foreach (module_implements($hook) as $module) {
webmaster@1:     $function = $module .'_'. $hook;
webmaster@1:     $result = call_user_func_array($function, $args);
webmaster@1:     if (isset($result) && is_array($result)) {
webmaster@1:       $return = array_merge_recursive($return, $result);
webmaster@1:     }
webmaster@1:     else if (isset($result)) {
webmaster@1:       $return[] = $result;
webmaster@1:     }
webmaster@1:   }
webmaster@1: 
webmaster@1:   return $return;
webmaster@1: }
webmaster@1: 
webmaster@1: /**
webmaster@1:  * @} End of "defgroup hooks".
webmaster@1:  */
webmaster@1: 
webmaster@1: /**
webmaster@1:  * Array of modules required by core.
webmaster@1:  */
webmaster@1: function drupal_required_modules() {
webmaster@1:   return array('block', 'filter', 'node', 'system', 'user');
webmaster@1: }