module.inc 16 KB
Newer Older
1 2 3
<?php
// $Id$

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

9
/**
10
 * Load all the modules that have been enabled in the system table.
11
 */
12
function module_load_all() {
13 14 15
  foreach (module_list(TRUE, FALSE) as $module) {
    drupal_load('module', $module);
  }
16 17
}

18 19 20 21
/**
 * Call a function repeatedly with each module in turn as an argument.
 */
function module_iterate($function, $argument = '') {
Kjartan's avatar
Kjartan committed
22 23 24
  foreach (module_list() as $name) {
    $function($name, $argument);
  }
25 26
}

27
/**
28 29
 * Collect a list of all loaded modules. During the bootstrap, return only
 * vital modules. See bootstrap.inc
30 31 32 33 34
 *
 * @param $refresh
 *   Whether to force the module list to be regenerated (such as after the
 *   administrator has changed the system settings).
 * @param $bootstrap
35 36
 *   Whether to return the reduced set of modules loaded in "bootstrap mode"
 *   for cached pages. See bootstrap.inc.
37 38 39
 * @param $sort
 *   By default, modules are ordered by weight and filename, settings this option
 *   to TRUE, module list will be ordered by module name.
40 41 42
 * @param $fixed_list
 *   (Optional) Override the module list with the given modules. Stays until the
 *   next call with $refresh = TRUE.
43 44 45 46
 * @return
 *   An associative array whose keys and values are the names of all loaded
 *   modules.
 */
47
function module_list($refresh = FALSE, $bootstrap = TRUE, $sort = FALSE, $fixed_list = NULL) {
48
  static $list, $sorted_list;
49

50
  if ($refresh || $fixed_list) {
51
    unset($sorted_list);
Dries's avatar
Dries committed
52
    $list = array();
53 54 55 56 57
    if ($fixed_list) {
      foreach ($fixed_list as $name => $module) {
        drupal_get_filename('module', $name, $module['filename']);
        $list[$name] = $name;
      }
58 59
    }
    else {
60
      if ($bootstrap) {
61
        $result = db_query("SELECT name, filename, throttle FROM {system} WHERE type = 'module' AND status = 1 AND bootstrap = 1 ORDER BY weight ASC, filename ASC");
62 63
      }
      else {
64
        $result = db_query("SELECT name, filename, throttle FROM {system} WHERE type = 'module' AND status = 1 ORDER BY weight ASC, filename ASC");
65 66 67 68 69 70 71 72 73 74 75
      }
      while ($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) > 0);
          if (!$throttle) {
            drupal_get_filename('module', $module->name, $module->filename);
            $list[$module->name] = $module->name;
          }
Dries's avatar
 
Dries committed
76
        }
77
      }
78 79
    }
  }
80 81 82 83 84 85 86
  if ($sort) {
    if (!isset($sorted_list)) {
      $sorted_list = $list;
      ksort($sorted_list);
    }
    return $sorted_list;
  }
87 88 89
  return $list;
}

Steven Wittens's avatar
Steven Wittens committed
90 91
/**
 * Rebuild the database cache of module files.
92
 *
Steven Wittens's avatar
Steven Wittens committed
93 94 95 96 97
 * @return
 *   The array of filesystem objects used to rebuild the cache.
 */
function module_rebuild_cache() {
  // Get current list of modules
98
  $files = drupal_system_listing('\.module$', 'modules', 'name', 0);
Steven Wittens's avatar
Steven Wittens committed
99 100 101 102 103 104

  // Extract current files from database.
  system_get_files_database($files, 'module');

  ksort($files);

105 106 107 108 109
  // Set defaults for module info
  $defaults = array(
    'dependencies' => array(),
    'dependents' => array(),
    'description' => '',
110 111
    'version' => NULL,
    'php' => DRUPAL_MINIMUM_PHP,
112 113
  );

Steven Wittens's avatar
Steven Wittens committed
114
  foreach ($files as $filename => $file) {
115 116 117
    // Look for the info file.
    $file->info = drupal_parse_info_file(dirname($file->filename) .'/'. $file->name .'.info');

118 119 120 121 122
    // Skip modules that don't provide info.
    if (empty($file->info)) {
      unset($files[$filename]);
      continue;
    }
123 124
    // Merge in defaults and save.
    $files[$filename]->info = $file->info + $defaults;
Steven Wittens's avatar
Steven Wittens committed
125

126 127 128 129
    // Invoke hook_system_info_alter() to give installed modules a chance to
    // modify the data in the .info files if necessary.
    drupal_alter('system_info', $files[$filename]->info, $files[$filename]);

130
    // Log the critical hooks implemented by this module.
Steven Wittens's avatar
Steven Wittens committed
131 132 133 134 135 136 137 138 139 140
    $bootstrap = 0;
    foreach (bootstrap_hooks() as $hook) {
      if (module_hook($file->name, $hook)) {
        $bootstrap = 1;
        break;
      }
    }

    // Update the contents of the system table:
    if (isset($file->status) || (isset($file->old_filename) && $file->old_filename != $file->filename)) {
141
      db_query("UPDATE {system} SET info = '%s', name = '%s', filename = '%s', bootstrap = %d WHERE filename = '%s'", serialize($files[$filename]->info), $file->name, $file->filename, $bootstrap, $file->old_filename);
Steven Wittens's avatar
Steven Wittens committed
142 143 144
    }
    else {
      // This is a new module.
145 146
      $files[$filename]->status = 0;
      $files[$filename]->throttle = 0;
147
      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);
Steven Wittens's avatar
Steven Wittens committed
148 149
    }
  }
150
  $files = _module_build_dependencies($files);
151 152
  return $files;
}
Steven Wittens's avatar
Steven Wittens committed
153

154
/**
155
 * Find dependencies any level deep and fill in dependents information too.
156
 *
157 158 159 160 161 162 163 164 165 166 167 168
 * If module A depends on B which in turn depends on C then this function will
 * add C to the list of modules A depends on. This will be repeated until
 * module A has a list of all modules it depends on. If it depends on itself,
 * called a circular dependency, that's marked by adding a nonexistent module,
 * called -circular- to this list of modules. Because this does not exist,
 * it'll be impossible to switch module A on.
 *
 * Also we fill in a dependents array in $file->info. Using the names above,
 * the dependents array of module B lists A.
 *
 * @param $files
 *   The array of filesystem objects used to rebuild the cache.
169
 * @return
170
 *   The same array with dependencies and dependents added where applicable.
171
 */
172 173 174 175 176 177 178 179 180
function _module_build_dependencies($files) {
  do {
    $new_dependency = FALSE;
    foreach ($files as $filename => $file) {
      // We will modify this object (module A, see doxygen for module A, B, C).
      $file = &$files[$filename];
      if (isset($file->info['dependencies']) && is_array($file->info['dependencies'])) {
        foreach ($file->info['dependencies'] as $dependency_name) {
          // This is a nonexistent module.
181
          if ($dependency_name == '-circular-' || !isset($files[$dependency_name])) {
182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210
            continue;
          }
          // $dependency_name is module B (again, see doxygen).
          $files[$dependency_name]->info['dependents'][$filename] = $filename;
          $dependency = $files[$dependency_name];
          if (isset($dependency->info['dependencies']) && is_array($dependency->info['dependencies'])) {
            // Let's find possible C modules.
            foreach ($dependency->info['dependencies'] as $candidate) {
              if (array_search($candidate, $file->info['dependencies']) === FALSE) {
                // Is this a circular dependency?
                if ($candidate == $filename) {
                  // As a module name can not contain dashes, this makes
                  // impossible to switch on the module.
                  $candidate = '-circular-';
                  // Do not display the message or add -circular- more than once.
                  if (array_search($candidate, $file->info['dependencies']) !== FALSE) {
                    continue;
                  }
                  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');
                }
                else {
                  // We added a new dependency to module A. The next loop will
                  // be able to use this as "B module" thus finding even
                  // deeper dependencies.
                  $new_dependency = TRUE;
                }
                $file->info['dependencies'][] = $candidate;
              }
            }
211 212 213
          }
        }
      }
214 215
      // Don't forget to break the reference.
      unset($file);
216
    }
217
  } while ($new_dependency);
Steven Wittens's avatar
Steven Wittens committed
218 219 220
  return $files;
}

221 222 223 224 225 226 227 228
/**
 * Determine whether a given module exists.
 *
 * @param $module
 *   The name of the module (without the .module extension).
 * @return
 *   TRUE if the module is both installed and enabled.
 */
229
function module_exists($module) {
230
  $list = module_list();
231
  return array_key_exists($module, $list);
232 233
}

Steven Wittens's avatar
Steven Wittens committed
234 235 236 237 238 239 240
/**
 * Load a module's installation hooks.
 */
function module_load_install($module) {
  // Make sure the installation API is available
  include_once './includes/install.inc';

241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276
  module_load_include('install', $module);
}

/**
 * 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;
  }

  $file = './'. drupal_get_path('module', $module) ."/$name.$type";

  if (is_file($file)) {
    require_once $file;
  }
  else {
    return FALSE;
  }
}

/**
 * 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
277 278 279 280
  }
}

/**
281
 * Enable a given list of modules.
Steven Wittens's avatar
Steven Wittens committed
282
 *
283 284
 * @param $module_list
 *   An array of module names.
Steven Wittens's avatar
Steven Wittens committed
285
 */
286 287 288
function module_enable($module_list) {
  $invoke_modules = array();
  foreach ($module_list as $module) {
289
    $existing = db_fetch_object(db_query("SELECT status FROM {system} WHERE type = '%s' AND name = '%s'", 'module', $module));
290
    if ($existing->status == 0) {
291
      module_load_install($module);
292
      db_query("UPDATE {system} SET status = %d, throttle = %d WHERE type = '%s' AND name = '%s'", 1, 0, 'module', $module);
293 294 295
      drupal_load('module', $module);
      $invoke_modules[] = $module;
    }
Steven Wittens's avatar
Steven Wittens committed
296
  }
297 298 299 300 301 302 303 304 305 306

  if (!empty($invoke_modules)) {
    // Refresh the module list to include the new enabled module.
    module_list(TRUE, FALSE);
    // Force to regenerate the stored list of hook implementations.
    module_implements('', FALSE, TRUE);
  }

  foreach ($invoke_modules as $module) {
    module_invoke($module, 'enable');
307
    // Check if node_access table needs rebuilding.
308 309 310 311
    // 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.
    if (function_exists('node_access_needs_rebuild') && !node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
312 313
      node_access_needs_rebuild(TRUE);
    }
Steven Wittens's avatar
Steven Wittens committed
314 315 316 317
  }
}

/**
318
 * Disable a given set of modules.
Steven Wittens's avatar
Steven Wittens committed
319
 *
320 321
 * @param $module_list
 *   An array of module names.
Steven Wittens's avatar
Steven Wittens committed
322
 */
323 324 325 326
function module_disable($module_list) {
  $invoke_modules = array();
  foreach ($module_list as $module) {
    if (module_exists($module)) {
327 328 329 330 331
      // Check if node_access table needs rebuilding.
      if (!node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
        node_access_needs_rebuild(TRUE);
      }

332 333
      module_load_install($module);
      module_invoke($module, 'disable');
334
      db_query("UPDATE {system} SET status = %d, throttle = %d WHERE type = '%s' AND name = '%s'", 0, 0, 'module', $module);
335 336
      $invoke_modules[] = $module;
    }
Steven Wittens's avatar
Steven Wittens committed
337
  }
338 339 340 341 342 343

  if (!empty($invoke_modules)) {
    // Refresh the module list to exclude the disabled modules.
    module_list(TRUE, FALSE);
    // Force to regenerate the stored list of hook implementations.
    module_implements('', FALSE, TRUE);
Steven Wittens's avatar
Steven Wittens committed
344
  }
345

346
  // If there remains no more node_access module, rebuilding will be
347 348 349 350
  // 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
351 352
}

353 354
/**
 * @defgroup hooks Hooks
Dries's avatar
 
Dries committed
355 356
 * @{
 * Allow modules to interact with the Drupal core.
357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386
 *
 * 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);
387 388
}

Dries's avatar
 
Dries committed
389 390 391 392 393
/**
 * Determine which modules are implementing a hook.
 *
 * @param $hook
 *   The name of the hook (e.g. "help" or "menu").
394 395 396
 * @param $sort
 *   By default, modules are ordered by weight and filename, settings this option
 *   to TRUE, module list will be ordered by module name.
397 398 399 400
 * @param $refresh
 *   For internal use only: Whether to force the stored list of hook
 *   implementations to be regenerated (such as after enabling a new module,
 *   before processing hook_enable).
Dries's avatar
 
Dries committed
401 402 403
 * @return
 *   An array with the names of the modules which are implementing this hook.
 */
404
function module_implements($hook, $sort = FALSE, $refresh = FALSE) {
Dries's avatar
 
Dries committed
405 406
  static $implementations;

407
  if ($refresh) {
408
    $implementations = array();
409 410 411
    return;
  }

Dries's avatar
 
Dries committed
412 413
  if (!isset($implementations[$hook])) {
    $implementations[$hook] = array();
414
    $list = module_list(FALSE, TRUE, $sort);
Dries's avatar
 
Dries committed
415 416 417 418 419 420 421
    foreach ($list as $module) {
      if (module_hook($module, $hook)) {
        $implementations[$hook][] = $module;
      }
    }
  }

422
  // The explicit cast forces a copy to be made. This is needed because
423 424 425 426 427 428
  // $implementations[$hook] is only a reference to an element of
  // $implementations and if there are nested foreaches (due to nested node
  // API calls, for example), they would both manipulate the same array's
  // references, which causes some modules' hooks not to be called.
  // See also http://www.zend.com/zend/art/ref-count.php.
  return (array)$implementations[$hook];
Dries's avatar
 
Dries committed
429 430
}

431 432 433 434 435 436 437 438 439 440 441 442
/**
 * 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.
 */
443 444
function module_invoke() {
  $args = func_get_args();
445 446 447
  $module = $args[0];
  $hook = $args[1];
  unset($args[0], $args[1]);
448
  $function = $module .'_'. $hook;
449 450
  if (module_hook($module, $hook)) {
    return call_user_func_array($function, $args);
451 452 453 454 455 456 457 458 459 460 461 462 463
  }
}
/**
 * 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.
 */
464 465
function module_invoke_all() {
  $args = func_get_args();
466 467
  $hook = $args[0];
  unset($args[0]);
468
  $return = array();
469 470 471
  foreach (module_implements($hook) as $module) {
    $function = $module .'_'. $hook;
    $result = call_user_func_array($function, $args);
472
    if (isset($result) && is_array($result)) {
473
      $return = array_merge_recursive($return, $result);
474
    }
475 476 477
    else if (isset($result)) {
      $return[] = $result;
    }
478 479 480 481 482 483
  }

  return $return;
}

/**
Dries's avatar
 
Dries committed
484
 * @} End of "defgroup hooks".
485 486
 */

487 488 489 490
/**
 * Array of modules required by core.
 */
function drupal_required_modules() {
491
  return array('block', 'filter', 'node', 'system', 'user');
492
}