module.inc 14.5 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 13 14 15 16 17 18 19
/**
 * Pass this to module_implements when its cache needs to be written.
 */
define('MODULE_IMPLEMENTS_WRITE_CACHE', -1);

/**
 * Pass this to module_implements when its cache needs to be cleared.
 */
define('MODULE_IMPLEMENTS_CLEAR_CACHE', -2);


20
/**
21
 * Load all the modules that have been enabled in the system table.
22
 */
23
function module_load_all() {
24
  foreach (module_list(TRUE) as $module) {
25 26
    drupal_load('module', $module);
  }
27 28
}

29
/**
30 31
 * Collect a list of all loaded modules. During the bootstrap, return only
 * vital modules. See bootstrap.inc
32 33 34 35
 *
 * @param $refresh
 *   Whether to force the module list to be regenerated (such as after the
 *   administrator has changed the system settings).
36
 * @param $sort
37 38
 *   By default, modules are ordered by weight and filename. Set this option to
 *   TRUE to return a module list ordered only by module name.
39 40 41
 * @param $fixed_list
 *   (Optional) Override the module list with the given modules. Stays until the
 *   next call with $refresh = TRUE.
42 43 44 45
 * @return
 *   An associative array whose keys and values are the names of all loaded
 *   modules.
 */
46
function module_list($refresh = FALSE, $sort = FALSE, $fixed_list = NULL) {
47
  static $list = array(), $sorted_list;
48

49
  if (empty($list) || $refresh || $fixed_list) {
Dries's avatar
Dries committed
50
    $list = array();
51
    $sorted_list = NULL;
52 53 54 55 56
    if ($fixed_list) {
      foreach ($fixed_list as $name => $module) {
        drupal_get_filename('module', $name, $module['filename']);
        $list[$name] = $name;
      }
57 58
    }
    else {
59
      $result = db_query("SELECT name, filename FROM {system} WHERE type = 'module' AND status = 1 ORDER BY weight ASC, filename ASC");
60
      foreach ($result as $module) {
61
        if (file_exists($module->filename)) {
62 63
          drupal_get_filename('module', $module->name, $module->filename);
          $list[$module->name] = $module->name;
Dries's avatar
 
Dries committed
64
        }
65
      }
66 67
    }
  }
68 69 70 71 72 73 74
  if ($sort) {
    if (!isset($sorted_list)) {
      $sorted_list = $list;
      ksort($sorted_list);
    }
    return $sorted_list;
  }
75 76 77
  return $list;
}

78
/**
79
 * Find dependencies any level deep and fill in required by information too.
80 81 82
 *
 * @param $files
 *   The array of filesystem objects used to rebuild the cache.
83
 * @return
84 85 86 87 88
 *   The same array with the new keys for each module:
 *   - requires: An array with the keys being the modules that this module
 *     requires.
 *   - required_by: An array with the keys being the modules that will not work
 *     without this module.
89
 */
90
function _module_build_dependencies($files) {
91
  require_once DRUPAL_ROOT . '/includes/graph.inc';
92 93 94 95 96 97 98
  $roots = $files;
  foreach ($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_name) {
        $graph[$file->name]['edges'][$dependency_name] = 1;
        unset($roots[$dependency_name]);
99 100
      }
    }
101 102 103
  }
  drupal_depth_first_search($graph, array_keys($roots));
  foreach ($graph as $module => $data) {
104
    $files[$module]->required_by = isset($data['reverse_paths']) ? $data['reverse_paths'] : array();
105 106 107
    $files[$module]->requires = isset($data['paths']) ? $data['paths'] : array();
    $files[$module]->sort = $data['weight'];
  }
Steven Wittens's avatar
Steven Wittens committed
108 109 110
  return $files;
}

111 112 113 114 115 116 117 118
/**
 * Determine whether a given module exists.
 *
 * @param $module
 *   The name of the module (without the .module extension).
 * @return
 *   TRUE if the module is both installed and enabled.
 */
119
function module_exists($module) {
120
  $list = module_list();
121
  return isset($list[$module]);
122 123
}

Steven Wittens's avatar
Steven Wittens committed
124 125 126 127 128
/**
 * Load a module's installation hooks.
 */
function module_load_install($module) {
  // Make sure the installation API is available
129
  include_once DRUPAL_ROOT . '/includes/install.inc';
Steven Wittens's avatar
Steven Wittens committed
130

131
  module_load_include('install', $module);
132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148
}

/**
 * Load a module include file.
 *
 * @param $type
 *   The include file's type (file extension).
 * @param $module
 *   The module to which the include file belongs.
 * @param $name
 *   Optionally, specify the file name. If not set, the module's name is used.
 */
function module_load_include($type, $module, $name = NULL) {
  if (empty($name)) {
    $name = $module;
  }

149
  if (drupal_function_exists('drupal_get_path')) {
150 151 152 153 154
    $file = DRUPAL_ROOT . '/' . drupal_get_path('module', $module) . "/$name.$type";
    if (is_file($file)) {
      require_once $file;
      return $file;
    }
155
  }
156
  return FALSE;
157 158 159 160 161 162 163 164 165 166
}

/**
 * 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);
Steven Wittens's avatar
Steven Wittens committed
167 168 169 170
  }
}

/**
171
 * Enable a given list of modules.
Steven Wittens's avatar
Steven Wittens committed
172
 *
173 174
 * @param $module_list
 *   An array of module names.
Steven Wittens's avatar
Steven Wittens committed
175
 */
176 177 178
function module_enable($module_list) {
  $invoke_modules = array();
  foreach ($module_list as $module) {
179 180 181 182
    $existing = db_query("SELECT status FROM {system} WHERE type = :type AND name = :name", array(
      ':type' => 'module',
      ':name' => $module))
      ->fetchObject();
183
    if ($existing->status == 0) {
184
      module_load_install($module);
185 186 187 188 189
      db_update('system')
        ->fields(array('status' => 1))
        ->condition('type', 'module')
        ->condition('name', $module)
        ->execute();
190 191
      drupal_load('module', $module);
      $invoke_modules[] = $module;
192
      watchdog('system', '%module module enabled.', array('%module' => $module), WATCHDOG_INFO);
193
    }
Steven Wittens's avatar
Steven Wittens committed
194
  }
195 196 197

  if (!empty($invoke_modules)) {
    // Refresh the module list to include the new enabled module.
198
    module_list(TRUE);
199
    // Force to regenerate the stored list of hook implementations.
200
    registry_rebuild();
201 202 203 204
  }

  foreach ($invoke_modules as $module) {
    module_invoke($module, 'enable');
205
    // Check if node_access table needs rebuilding.
206 207 208
    // 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.
209
    if (drupal_function_exists('node_access_needs_rebuild') && !node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
210 211
      node_access_needs_rebuild(TRUE);
    }
Steven Wittens's avatar
Steven Wittens committed
212
  }
213 214 215 216 217 218

  if (!empty($invoke_modules)) {
    // Invoke the hook_module_enable after all the modules have been
    // enabled.
    module_invoke_all('modules_enabled', $invoke_modules);
  }
Steven Wittens's avatar
Steven Wittens committed
219 220 221
}

/**
222
 * Disable a given set of modules.
Steven Wittens's avatar
Steven Wittens committed
223
 *
224 225
 * @param $module_list
 *   An array of module names.
Steven Wittens's avatar
Steven Wittens committed
226
 */
227 228 229 230
function module_disable($module_list) {
  $invoke_modules = array();
  foreach ($module_list as $module) {
    if (module_exists($module)) {
231 232 233 234 235
      // Check if node_access table needs rebuilding.
      if (!node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
        node_access_needs_rebuild(TRUE);
      }

236 237
      module_load_install($module);
      module_invoke($module, 'disable');
238 239 240 241 242
      db_update('system')
        ->fields(array('status' => 0))
        ->condition('type', 'module')
        ->condition('name', $module)
        ->execute();
243
      $invoke_modules[] = $module;
244
      watchdog('system', '%module module disabled.', array('%module' => $module), WATCHDOG_INFO);
245
    }
Steven Wittens's avatar
Steven Wittens committed
246
  }
247 248

  if (!empty($invoke_modules)) {
249 250 251
    // Invoke hook_module_disable before disabling modules,
    // so we can still call module hooks to get information.
    module_invoke_all('modules_disabled', $invoke_modules);
252
    // Refresh the module list to exclude the disabled modules.
253
    module_list(TRUE);
254
    // Force to regenerate the stored list of hook implementations.
255
    registry_rebuild();
Steven Wittens's avatar
Steven Wittens committed
256
  }
257

258
  // If there remains no more node_access module, rebuilding will be
259 260 261 262
  // straightforward, we can do it right now.
  if (node_access_needs_rebuild() && count(module_implements('node_grants')) == 0) {
    node_access_rebuild();
  }
Steven Wittens's avatar
Steven Wittens committed
263 264
}

265 266
/**
 * @defgroup hooks Hooks
Dries's avatar
 
Dries committed
267 268
 * @{
 * Allow modules to interact with the Drupal core.
269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297
 *
 * 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) {
298 299 300 301 302 303 304
  $function = $module . '_' . $hook;
  if (defined('MAINTENANCE_MODE')) {
    return function_exists($function);
  }
  else {
    return drupal_function_exists($function);
  }
305 306
}

Dries's avatar
 
Dries committed
307 308 309 310
/**
 * Determine which modules are implementing a hook.
 *
 * @param $hook
311 312
 *   The name of the hook (e.g. "help" or "menu"). Special cases:
 *     MODULE_IMPLEMENTS_CLEAR_CACHE: Force the stored list of hook
313
 *   implementations to be regenerated (such as after enabling a new module,
314 315 316 317
 *     before processing hook_enable).
 *     MODULE_IMPLEMENTS_WRITE_CACHE: Write the stored list of hook
 *     implementations into the cache_registry table.
 * @param $sort
318
 *   By default, modules are ordered by weight and filename. By setting this
319
 *   option to TRUE, modules will be ordered by module name.
Dries's avatar
 
Dries committed
320 321
 * @return
 *   An array with the names of the modules which are implementing this hook.
322 323
 *   All enabled modules are taken into consideration and the files containing
 *   the implementations are loaded as necessary.
Dries's avatar
 
Dries committed
324
 */
325 326
function module_implements($hook, $sort = FALSE) {
  static $implementations = array(), $sorted_implementations = array(), $loaded = array(), $cached_hooks = 0;
Dries's avatar
 
Dries committed
327

328 329
  if (defined('MAINTENANCE_MODE')) {
    return _module_implements_maintenance($hook, $sort);
330
  }
331
  if ($hook === MODULE_IMPLEMENTS_CLEAR_CACHE) {
332
    $implementations = array();
333 334 335 336 337
    $sorted_implementations = array();
    $loaded = array();
    $cached_hooks = 0;
    cache_clear_all('hooks', 'cache_registry');
    return;
338
  }
339 340 341 342 343 344
  if ($hook === MODULE_IMPLEMENTS_WRITE_CACHE) {
    // Only write this to cache if we loaded new implementations.
    if (count($implementations) > $cached_hooks) {
      cache_set('hooks', $implementations, 'cache_registry');
    }
    return;
345 346
  }

347 348 349 350 351
  if (!isset($loaded[$hook])) {
    if (empty($implementations) && ($cache = cache_get('hooks', 'cache_registry'))) {
      $implementations = $cache->data;
      $cached_hooks = count($implementations);
    }
352
    if (!isset($implementations[$hook])) {
353 354 355 356 357 358
      $implementations[$hook] = db_query("SELECT module FROM {registry} WHERE type = 'function' AND suffix = :hook ORDER BY weight, module", array(':hook' => $hook))->fetchCol();
    }
    foreach ($implementations[$hook] as $module) {
      $function = $module . '_' . $hook;
      if (!function_exists($function)) {
        drupal_function_exists($function);
Dries's avatar
 
Dries committed
359 360
      }
    }
361 362
    $loaded[$hook] = TRUE;
  }
Dries's avatar
 
Dries committed
363

364 365 366 367 368 369 370 371
  if ($sort) {
    if (!isset($sorted_implementations[$hook])) {
      $sorted_implementations[$hook] = $implementations[$hook];
      sort($sorted_implementations[$hook]);
    }
    return $sorted_implementations[$hook];
  }
  else {
372 373
    return $implementations[$hook];
  }
Dries's avatar
 
Dries committed
374 375
}

376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406
/**
 * This is the maintenance version of module_implements for internal use only.
 *
 * This function is called whenever MAINTENANCE_MODE is defined and is a
 * safe code path for Drupal installation or upgrade because it does not use
 * the database, instead it uses module_list. @see module_list $fixed_list on
 * how to make module_list also DB independent.
 *
 * @param $hook
 *   The name of the hook (e.g. "help" or "menu").
 * @param $sort
 *   By default, modules are ordered by weight and filename, settings this
 *   option to TRUE, module list will be ordered by module name.
 * @return
 *   An array with the names of the modules which are implementing this hook.
 *   Only enabled and already loaded modules are taken into consideration.
 */
function _module_implements_maintenance($hook, $sort = FALSE) {
  $implementations = array();
  foreach (module_list() as $module) {
    $function = $module . '_' . $hook;
    if (function_exists($function)) {
      $implementations[] = $module;
    }
    if ($sort) {
      sort($implementations);
    }
  }
  return $implementations;
}

407 408 409 410 411 412 413 414 415 416 417 418
/**
 * 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.
 */
419 420
function module_invoke() {
  $args = func_get_args();
421 422 423
  $module = $args[0];
  $hook = $args[1];
  unset($args[0], $args[1]);
424
  if (module_hook($module, $hook)) {
425
    return call_user_func_array($module . '_' . $hook, $args);
426 427 428 429 430 431 432 433 434 435 436 437 438
  }
}
/**
 * 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.
 */
439 440
function module_invoke_all() {
  $args = func_get_args();
441 442
  $hook = $args[0];
  unset($args[0]);
443
  $return = array();
444
  foreach (module_implements($hook) as $module) {
445
    $function = $module . '_' . $hook;
446 447 448 449 450
    if (drupal_function_exists($function)) {
      $result = call_user_func_array($function, $args);
      if (isset($result) && is_array($result)) {
        $return = array_merge_recursive($return, $result);
      }
451
      elseif (isset($result)) {
452 453
        $return[] = $result;
      }
454
    }
455 456 457 458 459 460
  }

  return $return;
}

/**
Dries's avatar
 
Dries committed
461
 * @} End of "defgroup hooks".
462 463
 */

464 465 466 467
/**
 * Array of modules required by core.
 */
function drupal_required_modules() {
468 469 470
  $files = drupal_system_listing('/\.info$/', 'modules', 'name', 0);
  $required = array();
  foreach ($files as $name => $file) {
471
    $info = drupal_parse_info_file($file->filepath);
472 473 474 475 476
    if (!empty($info) && !empty($info['required']) && $info['required']) {
      $required[] = $name;
    }
  }
  return $required;
477
}