<?php // $Id$ /** * @file * API for loading and interacting with Drupal modules. */ /** * Initialize all modules. * * To change the required set of modules, change this function as well as * system_listing() and module_list(). */ function module_init() { module_load_all(); module_invoke_all('init'); } /** * 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 installed and enabled modules. * * @param $refresh * Whether to force the module list to be regenerated (such as after the * administrator has changed the system settings). * @param $bootstrap * Whether to return the reduced set of modules loaded in "bootstrap mode" for * cached pages. See bootstrap.inc. * @return * An associative array whose keys and values are the names of all loaded * modules. */ function module_list($refresh = FALSE, $bootstrap = FALSE) { static $list; if ($refresh) { unset($list); } if (!$list) { $list = array('admin' => 'admin', 'filter' => 'filter', 'system' => 'system', 'user' => 'user', 'watchdog' => 'watchdog'); if ($bootstrap) { $result = db_query("SELECT name, filename, throttle, bootstrap FROM {system} WHERE type = 'module' AND status = 1 AND bootstrap = 1"); } else { $result = db_query("SELECT name, filename, throttle, bootstrap FROM {system} WHERE type = 'module' AND status = 1"); } while ($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) > 4); if (!$throttle) { $list[$module->name] = $module->name; module_set_filename($module->name, $module->filename); } } } asort($list); } return $list; } /** * Set the filename of a module, for future loading through module_load() * * @param $module * Name of the module which to specify the filename of. * @param $pa * Filename of the module named $module. * @return * Filename of module, if no $path has been specified. */ function module_set_filename($module, $path = null) { static $list; if ($path) { $list[$module] = $path; } else { return $list[$module] ? $list[$module] : "modules/$module.module"; } } /** * Retrieve the filename of a module * * @param $module * Name of the module which to retrieve the filename of. * @return * Filename of module. */ function module_get_filename($module) { return module_set_filename($module); } /** * Retrieve the path of a module * * @param $module * Name of the module which to retrieve the path of. * @return * Path of module. */ function module_get_path($module) { return dirname(module_get_filename($module)); } /** * Load a module into Drupal, but check first wether a module by the same name * has been loaded, and that the filename being included exists. * @param $module * The name of the module to be loaded. * @return * TRUE if the load was successfull. */ function module_load($module) { static $loaded = array(); if (!$loaded[$module]) { $filename = module_get_filename($module); if (file_exists($filename)) { include_once($filename); $loaded[$module] = $filename; return true; } } return false; } /** * Load all the modules that have been enabled in the system table. * * @return * TRUE if all modules were loaded successfully */ function module_load_all() { $list = module_list(); $status = true; foreach ($list as $module) { $status = $status && module_load($module); } return $status; } /** * Determine whether a given module exists. * * @param $module * The name of the module (without the .module extension). * @return * TRUE if the module is both installed and enabled. */ function module_exist($module) { $list = module_list(); return array_key_exists($module, $list); } /** * @defgroup hooks Hooks * * 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 call 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 is 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); } /** * 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, $a1 = NULL, $a2 = NULL, $a3 = NULL, $a4 = NULL) { $function = $module .'_'. $hook; if (function_exists($function)) { return $function($a1, $a2, $a3, $a4); } } /** * 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, $a1 = NULL, $a2 = NULL, $a3 = NULL, $a4 = NULL) { $return = array(); foreach (module_list() as $module) { $result = module_invoke($module, $hook, $a1, $a2, $a3, $a4); if (isset($result)) { $return = array_merge($return, $result); } } return $return; } /** * @} end of defgroup hooks */ ?>