module.inc 15.5 KB
Newer Older
1 2 3
<?php
// $Id$

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

9
/**
10
 * 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 FROM {system} WHERE type = 'module' AND status = 1 AND bootstrap = 1 ORDER BY weight ASC, filename ASC");
62 63
      }
      else {
64
        $result = db_query("SELECT name, filename FROM {system} WHERE type = 'module' AND status = 1 ORDER BY weight ASC, filename ASC");
65 66 67
      }
      while ($module = db_fetch_object($result)) {
        if (file_exists($module->filename)) {
68 69
          drupal_get_filename('module', $module->name, $module->filename);
          $list[$module->name] = $module->name;
Dries's avatar
 
Dries committed
70
        }
71
      }
72 73
    }
  }
74 75 76 77 78 79 80
  if ($sort) {
    if (!isset($sorted_list)) {
      $sorted_list = $list;
      ksort($sorted_list);
    }
    return $sorted_list;
  }
81 82 83
  return $list;
}

Steven Wittens's avatar
Steven Wittens committed
84 85
/**
 * Rebuild the database cache of module files.
86
 *
Steven Wittens's avatar
Steven Wittens committed
87 88 89 90 91
 * @return
 *   The array of filesystem objects used to rebuild the cache.
 */
function module_rebuild_cache() {
  // Get current list of modules
92
  $files = drupal_system_listing('\.module$', 'modules', 'name', 0);
Steven Wittens's avatar
Steven Wittens committed
93 94 95 96 97 98

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

  ksort($files);

99 100 101 102 103
  // Set defaults for module info
  $defaults = array(
    'dependencies' => array(),
    'dependents' => array(),
    'description' => '',
104 105
    'version' => NULL,
    'php' => DRUPAL_MINIMUM_PHP,
106 107
  );

Steven Wittens's avatar
Steven Wittens committed
108
  foreach ($files as $filename => $file) {
109
    // Look for the info file.
110
    $file->info = drupal_parse_info_file(dirname($file->filename) . '/' . $file->name . '.info');
111

112 113 114 115 116
    // Skip modules that don't provide info.
    if (empty($file->info)) {
      unset($files[$filename]);
      continue;
    }
117 118
    // Merge in defaults and save.
    $files[$filename]->info = $file->info + $defaults;
Steven Wittens's avatar
Steven Wittens committed
119

120 121 122 123
    // 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]);

124
    // Log the critical hooks implemented by this module.
Steven Wittens's avatar
Steven Wittens committed
125 126 127 128 129 130 131 132 133 134
    $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 != $file->filename)) {
135
      db_query("UPDATE {system} SET info = '%s', name = '%s', filename = '%s', bootstrap = %d WHERE filename = '%s'", serialize($files[$filename]->info), $file->name, $file->filename, $bootstrap, $file->old_filename);
Steven Wittens's avatar
Steven Wittens committed
136 137 138
    }
    else {
      // This is a new module.
139
      $files[$filename]->status = 0;
140
      db_query("INSERT INTO {system} (name, info, type, filename, status, bootstrap) VALUES ('%s', '%s', '%s', '%s', %d, %d)", $file->name, serialize($files[$filename]->info), 'module', $file->filename, 0, $bootstrap);
Steven Wittens's avatar
Steven Wittens committed
141 142
    }
  }
143
  $files = _module_build_dependencies($files);
144 145
  return $files;
}
Steven Wittens's avatar
Steven Wittens committed
146

147
/**
148
 * Find dependencies any level deep and fill in dependents information too.
149
 *
150 151 152 153 154 155 156 157 158 159 160 161
 * 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 $files
 *   The array of filesystem objects used to rebuild the cache.
162
 * @return
163
 *   The same array with dependencies and dependents added where applicable.
164
 */
165 166 167 168 169 170 171 172 173
function _module_build_dependencies($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 $dependency_name) {
          // This is a nonexistent module.
174
          if ($dependency_name == '-circular-' || !isset($files[$dependency_name])) {
175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203
            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'][] = $candidate;
              }
            }
204 205 206
          }
        }
      }
207 208
      // Don't forget to break the reference.
      unset($file);
209
    }
210
  } while ($new_dependency);
Steven Wittens's avatar
Steven Wittens committed
211 212 213
  return $files;
}

214 215 216 217 218 219 220 221
/**
 * Determine whether a given module exists.
 *
 * @param $module
 *   The name of the module (without the .module extension).
 * @return
 *   TRUE if the module is both installed and enabled.
 */
222
function module_exists($module) {
223
  $list = module_list();
224
  return array_key_exists($module, $list);
225 226
}

Steven Wittens's avatar
Steven Wittens committed
227 228 229 230 231 232 233
/**
 * Load a module's installation hooks.
 */
function module_load_install($module) {
  // Make sure the installation API is available
  include_once './includes/install.inc';

234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251
  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;
  }

252
  $file = './' . drupal_get_path('module', $module) . "/$name.$type";
253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269

  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
270 271 272 273
  }
}

/**
274
 * Enable a given list of modules.
Steven Wittens's avatar
Steven Wittens committed
275
 *
276 277
 * @param $module_list
 *   An array of module names.
Steven Wittens's avatar
Steven Wittens committed
278
 */
279 280 281
function module_enable($module_list) {
  $invoke_modules = array();
  foreach ($module_list as $module) {
282
    $existing = db_fetch_object(db_query("SELECT status FROM {system} WHERE type = '%s' AND name = '%s'", 'module', $module));
283
    if ($existing->status == 0) {
284
      module_load_install($module);
285
      db_query("UPDATE {system} SET status = %d WHERE type = '%s' AND name = '%s'", 1, 'module', $module);
286 287 288
      drupal_load('module', $module);
      $invoke_modules[] = $module;
    }
Steven Wittens's avatar
Steven Wittens committed
289
  }
290 291 292 293 294 295 296 297 298 299

  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');
300
    // Check if node_access table needs rebuilding.
301 302 303 304
    // 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')) {
305 306
      node_access_needs_rebuild(TRUE);
    }
Steven Wittens's avatar
Steven Wittens committed
307 308 309 310
  }
}

/**
311
 * Disable a given set of modules.
Steven Wittens's avatar
Steven Wittens committed
312
 *
313 314
 * @param $module_list
 *   An array of module names.
Steven Wittens's avatar
Steven Wittens committed
315
 */
316 317 318 319
function module_disable($module_list) {
  $invoke_modules = array();
  foreach ($module_list as $module) {
    if (module_exists($module)) {
320 321 322 323 324
      // Check if node_access table needs rebuilding.
      if (!node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
        node_access_needs_rebuild(TRUE);
      }

325 326
      module_load_install($module);
      module_invoke($module, 'disable');
327
      db_query("UPDATE {system} SET status = %d WHERE type = '%s' AND name = '%s'", 0, 'module', $module);
328 329
      $invoke_modules[] = $module;
    }
Steven Wittens's avatar
Steven Wittens committed
330
  }
331 332 333 334 335 336

  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
337
  }
338

339
  // If there remains no more node_access module, rebuilding will be
340 341 342 343
  // 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
344 345
}

346 347
/**
 * @defgroup hooks Hooks
Dries's avatar
 
Dries committed
348 349
 * @{
 * Allow modules to interact with the Drupal core.
350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378
 *
 * 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, $hook) {
379
  return function_exists($module . '_' . $hook);
380 381
}

Dries's avatar
 
Dries committed
382 383 384 385 386
/**
 * Determine which modules are implementing a hook.
 *
 * @param $hook
 *   The name of the hook (e.g. "help" or "menu").
387 388 389
 * @param $sort
 *   By default, modules are ordered by weight and filename, settings this option
 *   to TRUE, module list will be ordered by module name.
390 391 392 393
 * @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
394 395 396
 * @return
 *   An array with the names of the modules which are implementing this hook.
 */
397
function module_implements($hook, $sort = FALSE, $refresh = FALSE) {
Dries's avatar
 
Dries committed
398 399
  static $implementations;

400
  if ($refresh) {
401
    $implementations = array();
402 403 404
    return;
  }

Dries's avatar
 
Dries committed
405 406
  if (!isset($implementations[$hook])) {
    $implementations[$hook] = array();
407
    $list = module_list(FALSE, TRUE, $sort);
Dries's avatar
 
Dries committed
408 409 410 411 412 413 414
    foreach ($list as $module) {
      if (module_hook($module, $hook)) {
        $implementations[$hook][] = $module;
      }
    }
  }

415
  // The explicit cast forces a copy to be made. This is needed because
416 417 418 419 420 421
  // $implementations[$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
422 423
}

424 425 426 427 428 429 430 431 432 433 434 435
/**
 * 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.
 */
436 437
function module_invoke() {
  $args = func_get_args();
438 439 440
  $module = $args[0];
  $hook = $args[1];
  unset($args[0], $args[1]);
441
  $function = $module . '_' . $hook;
442 443
  if (module_hook($module, $hook)) {
    return call_user_func_array($function, $args);
444 445 446 447 448 449 450 451 452 453 454 455 456
  }
}
/**
 * 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.
 */
457 458
function module_invoke_all() {
  $args = func_get_args();
459 460
  $hook = $args[0];
  unset($args[0]);
461
  $return = array();
462
  foreach (module_implements($hook) as $module) {
463
    $function = $module . '_' . $hook;
464
    $result = call_user_func_array($function, $args);
465
    if (isset($result) && is_array($result)) {
466
      $return = array_merge_recursive($return, $result);
467
    }
468 469 470
    else if (isset($result)) {
      $return[] = $result;
    }
471 472 473 474 475 476
  }

  return $return;
}

/**
Dries's avatar
 
Dries committed
477
 * @} End of "defgroup hooks".
478 479
 */

480 481 482 483
/**
 * Array of modules required by core.
 */
function drupal_required_modules() {
484
  return array('block', 'filter', 'node', 'system', 'user');
485
}