module.inc 16.4 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 module name. 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 60 61 62 63 64
      // 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().
      $result = db_query("SELECT name, filename FROM {system} WHERE type = 'module' AND status = 1 ORDER BY weight ASC, name ASC");
65
      foreach ($result as $module) {
66
        if (file_exists($module->filename)) {
67 68
          drupal_get_filename('module', $module->name, $module->filename);
          $list[$module->name] = $module->name;
Dries's avatar
 
Dries committed
69
        }
70
      }
71 72
    }
  }
73 74 75 76 77 78 79
  if ($sort) {
    if (!isset($sorted_list)) {
      $sorted_list = $list;
      ksort($sorted_list);
    }
    return $sorted_list;
  }
80 81 82
  return $list;
}

83
/**
84
 * Find dependencies any level deep and fill in required by information too.
85 86 87
 *
 * @param $files
 *   The array of filesystem objects used to rebuild the cache.
88
 * @return
89 90 91 92 93
 *   The same array with the new keys for each module:
 *   - requires: An array with the keys being the modules that this module
 *     requires.
 *   - required_by: An array with the keys being the modules that will not work
 *     without this module.
94
 */
95
function _module_build_dependencies($files) {
96
  require_once DRUPAL_ROOT . '/includes/graph.inc';
97 98 99 100
  $roots = $files;
  foreach ($files as $filename => $file) {
    $graph[$file->name]['edges'] = array();
    if (isset($file->info['dependencies']) && is_array($file->info['dependencies'])) {
101 102 103 104
      foreach ($file->info['dependencies'] as $dependency) {
        $dependency_data = drupal_parse_dependency($dependency);
        $graph[$file->name]['edges'][$dependency_data['name']] = $dependency_data;
        unset($roots[$dependency_data['name']]);
105 106
      }
    }
107 108 109
  }
  drupal_depth_first_search($graph, array_keys($roots));
  foreach ($graph as $module => $data) {
110
    $files[$module]->required_by = isset($data['reverse_paths']) ? $data['reverse_paths'] : array();
111 112 113
    $files[$module]->requires = isset($data['paths']) ? $data['paths'] : array();
    $files[$module]->sort = $data['weight'];
  }
Steven Wittens's avatar
Steven Wittens committed
114 115 116
  return $files;
}

117 118 119 120 121 122 123 124
/**
 * Determine whether a given module exists.
 *
 * @param $module
 *   The name of the module (without the .module extension).
 * @return
 *   TRUE if the module is both installed and enabled.
 */
125
function module_exists($module) {
126
  $list = module_list();
127
  return isset($list[$module]);
128 129
}

Steven Wittens's avatar
Steven Wittens committed
130 131 132 133 134
/**
 * Load a module's installation hooks.
 */
function module_load_install($module) {
  // Make sure the installation API is available
135
  include_once DRUPAL_ROOT . '/includes/install.inc';
Steven Wittens's avatar
Steven Wittens committed
136

137
  module_load_include('install', $module);
138 139 140 141
}

/**
 * Load a module include file.
142
 *
143 144
 * Examples:
 * @code
145
 *   // Load node.admin.inc from the node module.
146
 *   module_load_include('inc', 'node', 'node.admin');
147
 *   // Load content_types.inc from the node module.
148
 *   module_load_include('inc', 'node', 'content_types');
149
 * @endcode
150
 *
151 152 153
 * Do not use this function to load an install file. Use module_load_install()
 * instead.
 *
154 155 156 157 158
 * @param $type
 *   The include file's type (file extension).
 * @param $module
 *   The module to which the include file belongs.
 * @param $name
159
 *   Optionally, specify the base file name (without the $type extension).
160
 *   If not set, $module is used.
161 162 163 164 165 166
 */
function module_load_include($type, $module, $name = NULL) {
  if (empty($name)) {
    $name = $module;
  }

167
  if (drupal_function_exists('drupal_get_path')) {
168 169 170 171 172
    $file = DRUPAL_ROOT . '/' . drupal_get_path('module', $module) . "/$name.$type";
    if (is_file($file)) {
      require_once $file;
      return $file;
    }
173
  }
174
  return FALSE;
175 176 177 178 179 180 181 182 183 184
}

/**
 * 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
185 186 187 188
  }
}

/**
189
 * Enable a given list of modules.
Steven Wittens's avatar
Steven Wittens committed
190
 *
191 192
 * @param $module_list
 *   An array of module names.
193 194
 * @param $disable_modules_installed_hook
 *   Normally just testing wants to set this to TRUE.
Steven Wittens's avatar
Steven Wittens committed
195
 */
196
function module_enable($module_list, $disable_modules_installed_hook = FALSE) {
197
  $invoke_modules = array();
198

199 200 201
  // Try to install the enabled modules and collect which were installed.
  // $module_list is not changed and already installed modules are ignored.
  $modules_installed = array_filter($module_list, '_drupal_install_module');
202
  foreach ($module_list as $module) {
203 204 205 206
    $existing = db_query("SELECT status FROM {system} WHERE type = :type AND name = :name", array(
      ':type' => 'module',
      ':name' => $module))
      ->fetchObject();
207
    if ($existing->status == 0) {
208
      module_load_install($module);
209 210 211 212 213
      db_update('system')
        ->fields(array('status' => 1))
        ->condition('type', 'module')
        ->condition('name', $module)
        ->execute();
214 215
      drupal_load('module', $module);
      $invoke_modules[] = $module;
216
      watchdog('system', '%module module enabled.', array('%module' => $module), WATCHDOG_INFO);
217
    }
Steven Wittens's avatar
Steven Wittens committed
218
  }
219 220 221

  if (!empty($invoke_modules)) {
    // Refresh the module list to include the new enabled module.
222
    module_list(TRUE);
223
    // Force to regenerate the stored list of hook implementations.
224
    registry_rebuild();
225 226 227 228 229

    // If any modules were newly installed, execute the hook for them.
    if (!$disable_modules_installed_hook && !empty($modules_installed)) {
      module_invoke_all('modules_installed', $modules_installed);
    }
230 231 232 233
  }

  foreach ($invoke_modules as $module) {
    module_invoke($module, 'enable');
234
    // Check if node_access table needs rebuilding.
235 236 237
    // 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.
238
    if (drupal_function_exists('node_access_needs_rebuild') && !node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
239 240
      node_access_needs_rebuild(TRUE);
    }
Steven Wittens's avatar
Steven Wittens committed
241
  }
242 243 244 245 246 247

  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
248 249 250
}

/**
251
 * Disable a given set of modules.
Steven Wittens's avatar
Steven Wittens committed
252
 *
253 254
 * @param $module_list
 *   An array of module names.
Steven Wittens's avatar
Steven Wittens committed
255
 */
256 257 258 259
function module_disable($module_list) {
  $invoke_modules = array();
  foreach ($module_list as $module) {
    if (module_exists($module)) {
260 261 262 263 264
      // Check if node_access table needs rebuilding.
      if (!node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
        node_access_needs_rebuild(TRUE);
      }

265 266
      module_load_install($module);
      module_invoke($module, 'disable');
267 268 269 270 271
      db_update('system')
        ->fields(array('status' => 0))
        ->condition('type', 'module')
        ->condition('name', $module)
        ->execute();
272
      $invoke_modules[] = $module;
273
      watchdog('system', '%module module disabled.', array('%module' => $module), WATCHDOG_INFO);
274
    }
Steven Wittens's avatar
Steven Wittens committed
275
  }
276 277

  if (!empty($invoke_modules)) {
278 279 280
    // Invoke hook_module_disable before disabling modules,
    // so we can still call module hooks to get information.
    module_invoke_all('modules_disabled', $invoke_modules);
281
    // Refresh the module list to exclude the disabled modules.
282
    module_list(TRUE);
283
    // Force to regenerate the stored list of hook implementations.
284
    registry_rebuild();
Steven Wittens's avatar
Steven Wittens committed
285
  }
286

287
  // If there remains no more node_access module, rebuilding will be
288 289 290 291
  // 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
292 293
}

294 295
/**
 * @defgroup hooks Hooks
Dries's avatar
 
Dries committed
296 297
 * @{
 * Allow modules to interact with the Drupal core.
298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326
 *
 * 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) {
327
  $function = $module . '_' . $hook;
328
  return function_exists($function) || drupal_function_exists($function);
329 330
}

Dries's avatar
 
Dries committed
331 332 333 334
/**
 * Determine which modules are implementing a hook.
 *
 * @param $hook
335 336
 *   The name of the hook (e.g. "help" or "menu"). Special cases:
 *     MODULE_IMPLEMENTS_CLEAR_CACHE: Force the stored list of hook
337
 *   implementations to be regenerated (such as after enabling a new module,
338 339 340 341
 *     before processing hook_enable).
 *     MODULE_IMPLEMENTS_WRITE_CACHE: Write the stored list of hook
 *     implementations into the cache_registry table.
 * @param $sort
342
 *   By default, modules are ordered by weight and module name. By setting this
343
 *   option to TRUE, modules will be ordered by module name.
Dries's avatar
 
Dries committed
344 345
 * @return
 *   An array with the names of the modules which are implementing this hook.
346 347
 *   All enabled modules are taken into consideration and the files containing
 *   the implementations are loaded as necessary.
Dries's avatar
 
Dries committed
348
 */
349
function module_implements($hook, $sort = FALSE) {
350
  static $implementations = array(), $sorted_implementations = array(), $loaded = array(), $cached_hooks = 0, $maintenance;
Dries's avatar
 
Dries committed
351

352 353 354 355 356 357 358
  // Use a static variable for maintenance mode to avoid the overhead of
  // calling defined() each time the function is called.
  if (!isset($maintenance)) {
    $maintenance = defined('MAINTENANCE_MODE');
  }

  if ($maintenance) {
359
    return _module_implements_maintenance($hook, $sort);
360
  }
361
  if ($hook === MODULE_IMPLEMENTS_CLEAR_CACHE) {
362
    $implementations = array();
363 364 365 366 367
    $sorted_implementations = array();
    $loaded = array();
    $cached_hooks = 0;
    cache_clear_all('hooks', 'cache_registry');
    return;
368
  }
369 370 371 372 373 374
  if ($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;
375 376
  }

377 378 379 380 381
  if (!isset($loaded[$hook])) {
    if (empty($implementations) && ($cache = cache_get('hooks', 'cache_registry'))) {
      $implementations = $cache->data;
      $cached_hooks = count($implementations);
    }
382
    if (!isset($implementations[$hook])) {
383 384 385 386 387
      // 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_list().
388 389 390 391 392 393
      $implementations[$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
394 395
      }
    }
396 397
    $loaded[$hook] = TRUE;
  }
Dries's avatar
 
Dries committed
398

399 400 401 402 403 404 405 406
  if ($sort) {
    if (!isset($sorted_implementations[$hook])) {
      $sorted_implementations[$hook] = $implementations[$hook];
      sort($sorted_implementations[$hook]);
    }
    return $sorted_implementations[$hook];
  }
  else {
407 408
    return $implementations[$hook];
  }
Dries's avatar
 
Dries committed
409 410
}

411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441
/**
 * 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;
}

442 443 444 445 446 447 448 449 450 451 452 453
/**
 * 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.
 */
454 455
function module_invoke() {
  $args = func_get_args();
456 457 458
  $module = $args[0];
  $hook = $args[1];
  unset($args[0], $args[1]);
459
  if (module_hook($module, $hook)) {
460
    return call_user_func_array($module . '_' . $hook, $args);
461 462 463 464 465 466 467 468 469 470 471 472 473
  }
}
/**
 * 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.
 */
474 475
function module_invoke_all() {
  $args = func_get_args();
476 477
  $hook = $args[0];
  unset($args[0]);
478
  $return = array();
479
  foreach (module_implements($hook) as $module) {
480
    $function = $module . '_' . $hook;
481 482 483 484 485
    if (drupal_function_exists($function)) {
      $result = call_user_func_array($function, $args);
      if (isset($result) && is_array($result)) {
        $return = array_merge_recursive($return, $result);
      }
486
      elseif (isset($result)) {
487 488
        $return[] = $result;
      }
489
    }
490 491 492 493 494 495
  }

  return $return;
}

/**
Dries's avatar
 
Dries committed
496
 * @} End of "defgroup hooks".
497 498
 */

499 500 501 502
/**
 * Array of modules required by core.
 */
function drupal_required_modules() {
503 504 505
  $files = drupal_system_listing('/\.info$/', 'modules', 'name', 0);
  $required = array();
  foreach ($files as $name => $file) {
506
    $info = drupal_parse_info_file($file->uri);
507 508 509 510 511
    if (!empty($info) && !empty($info['required']) && $info['required']) {
      $required[] = $name;
    }
  }
  return $required;
512
}