module.inc 5.13 KB
Newer Older
1 2 3
<?php
// $Id$

4 5 6 7 8
/**
 * @file
 * API for loading and interacting with Drupal modules.
 */

9 10 11 12
/**
 * Call a function repeatedly with each module in turn as an argument.
 */
function module_iterate($function, $argument = '') {
Kjartan's avatar
Kjartan committed
13 14 15
  foreach (module_list() as $name) {
    $function($name, $argument);
  }
16 17
}

18 19 20 21 22 23 24 25 26 27 28 29 30 31
/**
 * 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) {
32 33
  static $list;

Dries's avatar
 
Dries committed
34
  if ($refresh) {
Dries's avatar
Dries committed
35
    $list = array();
Dries's avatar
 
Dries committed
36 37
  }

38
  if (!$list) {
39
    $list = array('admin' => 'admin', 'filter' => 'filter', 'system' => 'system', 'user' => 'user', 'watchdog' => 'watchdog');
40 41 42 43 44 45
    if ($bootstrap) {
      $result = db_query("SELECT name, filename, throttle, bootstrap FROM {system} WHERE type = 'module' AND status = 1 AND bootstrap = 1");
    }
    else {
      $result = db_query("SELECT name, filename, throttle, bootstrap FROM {system} WHERE type = 'module' AND status = 1");
    }
46
    while ($module = db_fetch_object($result)) {
Dries's avatar
 
Dries committed
47
      if (file_exists($module->filename)) {
48 49 50
        // 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.
51
        $throttle = ($module->throttle && variable_get('throttle_level', 0) > 0);
52
        if (!$throttle) {
Dries's avatar
Dries committed
53
          drupal_get_filename('module', $module->name, $module->filename);
Dries's avatar
 
Dries committed
54 55
          $list[$module->name] = $module->name;
        }
56
      }
57
    }
Dries's avatar
 
Dries committed
58
    asort($list);
59 60 61 62
  }
  return $list;
}

Dries's avatar
 
Dries committed
63 64 65 66
/**
 * Load all the modules that have been enabled in the system table.
 *
 * @return
Dries's avatar
Dries committed
67
 *   TRUE if all modules were loaded successfully.
Dries's avatar
 
Dries committed
68 69
 */
function module_load_all() {
Dries's avatar
Dries committed
70
  $list = module_list(TRUE, FALSE);
Dries's avatar
Dries committed
71 72
  $status = TRUE;

Dries's avatar
 
Dries committed
73
  foreach ($list as $module) {
Dries's avatar
Dries committed
74
    $status = (drupal_load('module', $module) && $status);
Dries's avatar
 
Dries committed
75
  }
Dries's avatar
Dries committed
76

Dries's avatar
 
Dries committed
77 78 79 80
  return $status;
}


81 82 83 84 85 86 87 88 89
/**
 * 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) {
90
  $list = module_list();
91
  return array_key_exists($module, $list);
92 93
}

94 95
/**
 * @defgroup hooks Hooks
Dries's avatar
 
Dries committed
96 97
 * @{
 * Allow modules to interact with the Drupal core.
98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127
 *
 * 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);
128 129
}

130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163
/**
 * 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, $a4);
164
    if (is_array($result)) {
165 166
      $return = array_merge($return, $result);
    }
167 168 169
    else if (isset($result)) {
      $return[] = $result;
    }
170 171 172 173 174 175
  }

  return $return;
}

/**
Dries's avatar
 
Dries committed
176
 * @} End of "defgroup hooks".
177 178
 */

Dries's avatar
 
Dries committed
179
?>