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
 * Collect a list of all loaded modules. During the bootstrap, return only
 * vital modules. See bootstrap.inc
21
22
23
24
25
 *
 * @param $refresh
 *   Whether to force the module list to be regenerated (such as after the
 *   administrator has changed the system settings).
 * @param $bootstrap
26
27
 *   Whether to return the reduced set of modules loaded in "bootstrap mode"
 *   for cached pages. See bootstrap.inc.
28
29
30
 * @param $sort
 *   By default, modules are ordered by weight and filename, settings this option
 *   to TRUE, module list will be ordered by module name.
31
32
33
 * @param $fixed_list
 *   (Optional) Override the module list with the given modules. Stays until the
 *   next call with $refresh = TRUE.
34
35
36
37
 * @return
 *   An associative array whose keys and values are the names of all loaded
 *   modules.
 */
38
function module_list($refresh = FALSE, $bootstrap = TRUE, $sort = FALSE, $fixed_list = NULL) {
39
  static $list = array(), $sorted_list;
40

41
  if (empty($list) || $refresh || $fixed_list) {
42
    unset($sorted_list);
Dries's avatar
Dries committed
43
    $list = array();
44
45
46
47
48
    if ($fixed_list) {
      foreach ($fixed_list as $name => $module) {
        drupal_get_filename('module', $name, $module['filename']);
        $list[$name] = $name;
      }
49
50
    }
    else {
51
      if ($bootstrap) {
52
        $result = db_query("SELECT name, filename FROM {system} WHERE type = 'module' AND status = 1 AND bootstrap = 1 ORDER BY weight ASC, filename ASC");
53
54
      }
      else {
55
        $result = db_query("SELECT name, filename FROM {system} WHERE type = 'module' AND status = 1 ORDER BY weight ASC, filename ASC");
56
57
58
      }
      while ($module = db_fetch_object($result)) {
        if (file_exists($module->filename)) {
59
60
          drupal_get_filename('module', $module->name, $module->filename);
          $list[$module->name] = $module->name;
Dries's avatar
   
Dries committed
61
        }
62
      }
63
64
    }
  }
65
66
67
68
69
70
71
  if ($sort) {
    if (!isset($sorted_list)) {
      $sorted_list = $list;
      ksort($sorted_list);
    }
    return $sorted_list;
  }
72
73
74
  return $list;
}

Steven Wittens's avatar
Steven Wittens committed
75
76
/**
 * Rebuild the database cache of module files.
77
 *
Steven Wittens's avatar
Steven Wittens committed
78
79
80
81
82
 * @return
 *   The array of filesystem objects used to rebuild the cache.
 */
function module_rebuild_cache() {
  // Get current list of modules
83
  $files = drupal_system_listing('/\.module$/', 'modules', 'name', 0);
Steven Wittens's avatar
Steven Wittens committed
84
85
86
87
88
89

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

  ksort($files);

90
91
92
93
94
  // Set defaults for module info
  $defaults = array(
    'dependencies' => array(),
    'dependents' => array(),
    'description' => '',
95
    'package' => 'Other',
96
97
    'version' => NULL,
    'php' => DRUPAL_MINIMUM_PHP,
98
99
  );

Steven Wittens's avatar
Steven Wittens committed
100
  foreach ($files as $filename => $file) {
101
    // Look for the info file.
102
    $file->info = drupal_parse_info_file(dirname($file->filename) . '/' . $file->name . '.info');
103

104
105
106
107
108
    // Skip modules that don't provide info.
    if (empty($file->info)) {
      unset($files[$filename]);
      continue;
    }
109
110
    // Merge in defaults and save.
    $files[$filename]->info = $file->info + $defaults;
Steven Wittens's avatar
Steven Wittens committed
111

112
113
114
115
    // 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]);

116
    // Log the critical hooks implemented by this module.
Steven Wittens's avatar
Steven Wittens committed
117
118
119
120
121
122
123
124
125
126
    $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 != $file->filename)) {
127
      db_query("UPDATE {system} SET info = '%s', name = '%s', filename = '%s', bootstrap = %d WHERE filename = '%s'", serialize($files[$filename]->info), $file->name, $file->filename, $bootstrap, $file->old_filename);
Steven Wittens's avatar
Steven Wittens committed
128
129
130
    }
    else {
      // This is a new module.
131
      $files[$filename]->status = 0;
132
      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
133
134
    }
  }
135
  $files = _module_build_dependencies($files);
136
137
  return $files;
}
Steven Wittens's avatar
Steven Wittens committed
138

139
/**
140
 * Find dependencies any level deep and fill in dependents information too.
141
 *
142
143
144
145
146
147
148
149
150
151
152
153
 * 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 $files
 *   The array of filesystem objects used to rebuild the cache.
154
 * @return
155
 *   The same array with dependencies and dependents added where applicable.
156
 */
157
158
159
160
161
162
163
164
165
function _module_build_dependencies($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 $dependency_name) {
          // This is a nonexistent module.
166
          if ($dependency_name == '-circular-' || !isset($files[$dependency_name])) {
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
            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'][] = $candidate;
              }
            }
196
197
198
          }
        }
      }
199
200
      // Don't forget to break the reference.
      unset($file);
201
    }
202
  } while ($new_dependency);
Steven Wittens's avatar
Steven Wittens committed
203
204
205
  return $files;
}

206
207
208
209
210
211
212
213
/**
 * Determine whether a given module exists.
 *
 * @param $module
 *   The name of the module (without the .module extension).
 * @return
 *   TRUE if the module is both installed and enabled.
 */
214
function module_exists($module) {
215
  $list = module_list();
216
  return isset($list[$module]);
217
218
}

Steven Wittens's avatar
Steven Wittens committed
219
220
221
222
223
/**
 * Load a module's installation hooks.
 */
function module_load_install($module) {
  // Make sure the installation API is available
224
  include_once DRUPAL_ROOT . '/includes/install.inc';
Steven Wittens's avatar
Steven Wittens committed
225

226
  module_load_include('install', $module);
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
}

/**
 * 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;
  }

244
  if (drupal_function_exists('drupal_get_path')) {
245
246
247
248
249
    $file = DRUPAL_ROOT . '/' . drupal_get_path('module', $module) . "/$name.$type";
    if (is_file($file)) {
      require_once $file;
      return $file;
    }
250
  }
251
  return FALSE;
252
253
254
255
256
257
258
259
260
261
}

/**
 * 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
262
263
264
265
  }
}

/**
266
 * Enable a given list of modules.
Steven Wittens's avatar
Steven Wittens committed
267
 *
268
269
 * @param $module_list
 *   An array of module names.
Steven Wittens's avatar
Steven Wittens committed
270
 */
271
272
273
function module_enable($module_list) {
  $invoke_modules = array();
  foreach ($module_list as $module) {
274
    $existing = db_fetch_object(db_query("SELECT status FROM {system} WHERE type = '%s' AND name = '%s'", 'module', $module));
275
    if ($existing->status == 0) {
276
      module_load_install($module);
277
      db_query("UPDATE {system} SET status = %d WHERE type = '%s' AND name = '%s'", 1, 'module', $module);
278
279
280
      drupal_load('module', $module);
      $invoke_modules[] = $module;
    }
Steven Wittens's avatar
Steven Wittens committed
281
  }
282
283
284
285
286

  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.
287
    registry_rebuild();
288
289
290
291
  }

  foreach ($invoke_modules as $module) {
    module_invoke($module, 'enable');
292
    // Check if node_access table needs rebuilding.
293
294
295
    // 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.
296
    if (drupal_function_exists('node_access_needs_rebuild') && !node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
297
298
      node_access_needs_rebuild(TRUE);
    }
Steven Wittens's avatar
Steven Wittens committed
299
  }
300
301
302
303
304
305

  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
306
307
308
}

/**
309
 * Disable a given set of modules.
Steven Wittens's avatar
Steven Wittens committed
310
 *
311
312
 * @param $module_list
 *   An array of module names.
Steven Wittens's avatar
Steven Wittens committed
313
 */
314
315
316
317
function module_disable($module_list) {
  $invoke_modules = array();
  foreach ($module_list as $module) {
    if (module_exists($module)) {
318
319
320
321
322
      // Check if node_access table needs rebuilding.
      if (!node_access_needs_rebuild() && module_hook($module, 'node_grants')) {
        node_access_needs_rebuild(TRUE);
      }

323
324
      module_load_install($module);
      module_invoke($module, 'disable');
325
      db_query("UPDATE {system} SET status = %d WHERE type = '%s' AND name = '%s'", 0, 'module', $module);
326
327
      $invoke_modules[] = $module;
    }
Steven Wittens's avatar
Steven Wittens committed
328
  }
329
330

  if (!empty($invoke_modules)) {
331
332
333
    // Invoke hook_module_disable before disabling modules,
    // so we can still call module hooks to get information.
    module_invoke_all('modules_disabled', $invoke_modules);
334
335
336
    // Refresh the module list to exclude the disabled modules.
    module_list(TRUE, FALSE);
    // Force to regenerate the stored list of hook implementations.
337
    registry_rebuild();
Steven Wittens's avatar
Steven Wittens committed
338
  }
339

340
  // If there remains no more node_access module, rebuilding will be
341
342
343
344
  // 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
345
346
}

347
348
/**
 * @defgroup hooks Hooks
Dries's avatar
   
Dries committed
349
350
 * @{
 * Allow modules to interact with the Drupal core.
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
379
 *
 * 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) {
380
381
382
383
384
385
386
  $function = $module . '_' . $hook;
  if (defined('MAINTENANCE_MODE')) {
    return function_exists($function);
  }
  else {
    return drupal_function_exists($function);
  }
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
 * @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,
400
401
 *   before processing hook_enable).  Note that if $refresh is TRUE this function
 *   will always return NULL.
Dries's avatar
   
Dries committed
402
403
 * @return
 *   An array with the names of the modules which are implementing this hook.
404
 *   If $hook is NULL then it will return the implementation cache.
Dries's avatar
   
Dries committed
405
 */
406
function module_implements($hook = NULL, $sort = FALSE, $refresh = FALSE) {
407
  static $implementations = array();
Dries's avatar
   
Dries committed
408

409
410
411
  if (!isset($hook)) {
    return $implementations;
  }
412
  if ($refresh) {
413
    $implementations = array();
414
  }
415
416
  if (!defined('MAINTENANCE_MODE') && empty($implementations) && ($cache = cache_get('hooks', 'cache_registry'))) {
    $implementations = $cache->data;
417
418
  }

419
420
421
422
423
424
425
  if ($hook) {
    if (!isset($implementations[$hook])) {
      $implementations[$hook] = array();
      foreach (module_list() as $module) {
        if (module_hook($module, $hook)) {
          $implementations[$hook][] = $module;
        }
Dries's avatar
   
Dries committed
426
427
      }
    }
428
    registry_cache_hook_implementations(array('hook' => $hook, 'modules' => $implementations[$hook]));
Dries's avatar
   
Dries committed
429

430
431
    return $implementations[$hook];
  }
Dries's avatar
   
Dries committed
432
433
}

434
435
436
437
438
439
440
441
442
443
444
445
/**
 * 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.
 */
446
447
function module_invoke() {
  $args = func_get_args();
448
449
450
  $module = $args[0];
  $hook = $args[1];
  unset($args[0], $args[1]);
451
  if (module_hook($module, $hook)) {
452
    return call_user_func_array($module . '_' . $hook, $args);
453
454
455
456
457
458
459
460
461
462
463
464
465
  }
}
/**
 * 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.
 */
466
467
function module_invoke_all() {
  $args = func_get_args();
468
469
  $hook = $args[0];
  unset($args[0]);
470
  $return = array();
471
  foreach (module_implements($hook) as $module) {
472
    $function = $module . '_' . $hook;
473
474
475
476
477
478
479
480
    if (drupal_function_exists($function)) {
      $result = call_user_func_array($function, $args);
      if (isset($result) && is_array($result)) {
        $return = array_merge_recursive($return, $result);
      }
      else if (isset($result)) {
        $return[] = $result;
      }
481
    }
482
483
484
485
486
487
  }

  return $return;
}

/**
Dries's avatar
   
Dries committed
488
 * @} End of "defgroup hooks".
489
490
 */

491
492
493
494
/**
 * Array of modules required by core.
 */
function drupal_required_modules() {
495
  return array('block', 'filter', 'node', 'system', 'user');
496
}