node.api.php 41.4 KB
Newer Older
1 2 3 4 5 6 7 8
<?php
// $Id$

/**
 * @file
 * Hooks provided by the Node module.
 */

9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
/**
 * @defgroup node_api_hooks Node API Hooks
 * @{
 * The Node API allows modules to define content types, to modify content
 * types created in the user interface, and to modify content types created by
 * other modules.
 *
 * Each content type is maintained by a primary module, which is either
 * node.module (for content types created in the user interface) or the
 * module that implements hook_node_info() to define the content type.
 *
 * During node operations (create, update, view, delete, etc.), there are
 * several sets of hooks that get invoked to allow modules to modify the base
 * node operation:
 * - Node-type-specific hooks: These hooks are only invoked on the primary
 *   module, using the "base" return component of hook_node_info() as the
25 26 27
 *   function prefix.  For example, poll.module defines the base for the Poll
 *   content type as "poll", so during creation of a poll node, hook_insert() is
 *   only invoked by calling poll_insert().
28 29 30
 * - All-module hooks: This set of hooks is invoked on all implementing
 *   modules, to allow other modules to modify what the primary node module is
 *   doing. For example, hook_node_insert() is invoked on all modules when
31
 *   creating a poll node.
32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71
 * - Field hooks: Hooks related to the fields attached to the node. These are
 *   invoked from the field operations functions described below, and can be
 *   either field-type-specific or all-module hooks.
 * - Entity hooks: Generic hooks for "entity" operations. These are always
 *   invoked on all modules.
 *
 * Here is a list of the node and entity hooks that are invoked, field
 * operations, and other steps that take place during node operations:
 * - Creating a new node (calling node_save() on a new node):
 *   - field_attach_presave()
 *   - hook_node_presave() (all)
 *   - Node and revision records are written to the database
 *   - hook_insert() (node-type-specific)
 *   - field_attach_insert()
 *   - hook_node_insert() (all)
 *   - hook_entity_insert() (all)
 *   - hook_node_access_records() (all)
 *   - hook_node_access_records_alter() (all)
 * - Updating an existing node (calling node_save() on an existing node):
 *   - field_attach_presave()
 *   - hook_node_presave() (all)
 *   - Node and revision records are written to the database
 *   - hook_update() (node-type-specific)
 *   - field_attach_update()
 *   - hook_node_update() (all)
 *   - hook_entity_update() (all)
 *   - hook_node_access_records() (all)
 *   - hook_node_access_records_alter() (all)
 * - Loading a node (calling node_load(), node_load_multiple(), or
 *   entity_load() with $entity_type of 'node'):
 *   - Node and revision information is read from database.
 *   - hook_load() (node-type-specific)
 *   - field_attach_load_revision() and field_attach_load()
 *   - hook_entity_load() (all)
 *   - hook_node_load() (all)
 * - Viewing a single node (calling node_view() - note that the input to
 *   node_view() is a loaded node, so the Loading steps above are already
 *   done):
 *   - hook_view() (node-type-specific)
 *   - field_attach_prepare_view()
72
 *   - hook_entity_prepare_view() (all)
73 74 75 76 77 78
 *   - field_attach_view()
 *   - hook_node_view() (all)
 * - Viewing multiple nodes (calling node_view_multiple() - note that the input
 *   to node_view_multiple() is a set of loaded nodes, so the Loading steps
 *   above are already done):
 *   - field_attach_prepare_view()
79
 *   - hook_entity_prepare_view() (all)
80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98
 *   - hook_view() (node-type-specific)
 *   - field_attach_view()
 *   - hook_node_view() (all)
 *   - hook_node_view_alter() (all)
 * - Deleting a node (calling node_delete() or node_delete_multiple()):
 *   - Node is loaded (see Loading section above)
 *   - Node and revision information is deleted from database
 *   - hook_delete() (node-type-specific)
 *   - hook_node_delete() (all)
 *   - field_attach_delete()
 * - Deleting a node revision (calling node_revision_delete()):
 *   - Node is loaded (see Loading section above)
 *   - Revision information is deleted from database
 *   - hook_node_revision_delete() (all)
 *   - field_attach_delete_revision()
 * - Preparing a node for editing (calling node_form() - note that if it's
 *   an existing node, it will already be loaded; see the Loading section
 *   above):
 *   - hook_prepare() (node-type-specific)
99
 *   - hook_node_prepare() (all); if translation.module is enabled, this will
100
 *     also invoke hook_node_prepare_translation() on all modules.
101 102 103 104 105 106 107 108 109 110 111 112
 *   - hook_form() (node-type-specific)
 *   - field_attach_form()
 * - Validating a node during editing form submit (calling
 *   node_form_validate()):
 *   - hook_validate() (node-type-specific)
 *   - hook_node_validate() (all)
 *   - field_attach_form_validate()
 * - Searching (calling node_search_execute()):
 *   - hook_ranking() (all)
 *   - Query is executed to find matching nodes
 *   - Resulting node is loaded (see Loading section above)
 *   - Resulting node is prepared for viewing (see Viewing a single node above)
113
 *   - comment_node_update_index() is called.
114 115 116 117 118 119 120 121
 *   - hook_node_search_result() (all)
 * - Search indexing (calling node_update_index()):
 *   - Node is loaded (see Loading section above)
 *   - Node is prepared for viewing (see Viewing a single node above)
 *   - hook_node_update_index() (all)
 * @}
 */

122 123 124 125 126 127 128 129
/**
 * @addtogroup hooks
 * @{
 */

/**
 * Inform the node access system what permissions the user has.
 *
130 131 132 133
 * This hook is for implementation by node access modules. In this hook,
 * the module grants a user different "grant IDs" within one or more
 * "realms". In hook_node_access_records(), the realms and grant IDs are
 * associated with permission to view, edit, and delete individual nodes.
134
 *
135 136 137 138 139
 * The realms and grant IDs can be arbitrarily defined by your node access
 * module; it is common to use role IDs as grant IDs, but that is not
 * required. Your module could instead maintain its own list of users, where
 * each list has an ID. In that case, the return value of this hook would be
 * an array of the list IDs that this user is a member of.
140 141 142 143
 *
 * A node access module may implement as many realms as necessary to
 * properly define the access privileges for the nodes.
 *
144
 * @param $account
145 146 147
 *   The user object whose grants are requested.
 * @param $op
 *   The node operation to be performed, such as "view", "update", or "delete".
148
 *
149
 * @return
150 151
 *   An array whose keys are "realms" of grants, and whose values are arrays of
 *   the grant IDs within this realm that this user is being granted.
152 153 154 155 156 157 158 159 160
 *
 * For a detailed example, see node_access_example.module.
 *
 * @ingroup node_access
 */
function hook_node_grants($account, $op) {
  if (user_access('access private content', $account)) {
    $grants['example'] = array(1);
  }
161
  $grants['example_owner'] = array($account->uid);
162 163 164 165 166 167
  return $grants;
}

/**
 * Set permissions for a node to be written to the database.
 *
168 169 170
 * When a node is saved, a module implementing hook_node_access_records() will
 * be asked if it is interested in the access permissions for a node. If it is
 * interested, it must respond with an array of permissions arrays for that
171 172
 * node.
 *
173 174 175
 * Note that the grant values in the return value from your hook must be
 * integers and not boolean TRUE and FALSE.
 *
176 177 178 179
 * Each permissions item in the array is an array with the following elements:
 * - 'realm': The name of a realm that the module has defined in
 *   hook_node_grants().
 * - 'gid': A 'grant ID' from hook_node_grants().
180
 * - 'grant_view': If set to 1 a user that has been identified as a member
181
 *   of this gid within this realm can view this node.
182
 * - 'grant_update': If set to 1 a user that has been identified as a member
183
 *   of this gid within this realm can edit this node.
184
 * - 'grant_delete': If set to 1 a user that has been identified as a member
185 186 187 188 189
 *   of this gid within this realm can delete this node.
 * - 'priority': If multiple modules seek to set permissions on a node, the
 *   realms that have the highest priority will win out, and realms with a lower
 *   priority will not be written. If there is any doubt, it is best to
 *   leave this 0.
190 191 192
 *
 * @ingroup node_access
 */
193
function hook_node_access_records($node) {
194 195 196 197
  if (node_access_example_disabling()) {
    return;
  }

198
  // We only care about the node if it has been marked private. If not, it is
199 200 201 202 203
  // treated just like any other node and we completely ignore it.
  if ($node->private) {
    $grants = array();
    $grants[] = array(
      'realm' => 'example',
204 205 206 207
      'gid' => 1,
      'grant_view' => 1,
      'grant_update' => 0,
      'grant_delete' => 0,
208 209 210 211 212 213 214 215
      'priority' => 0,
    );

    // For the example_author array, the GID is equivalent to a UID, which
    // means there are many many groups of just 1 user.
    $grants[] = array(
      'realm' => 'example_author',
      'gid' => $node->uid,
216 217 218
      'grant_view' => 1,
      'grant_update' => 1,
      'grant_delete' => 1,
219 220 221 222 223 224
      'priority' => 0,
    );
    return $grants;
  }
}

225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250
/**
 * Alter permissions for a node before it is written to the database.
 *
 * Node access modules establish rules for user access to content. Node access
 * records are stored in the {node_access} table and define which permissions
 * are required to access a node. This hook is invoked after node access modules
 * returned their requirements via hook_node_access_records(); doing so allows
 * modules to modify the $grants array by reference before it is stored, so
 * custom or advanced business logic can be applied.
 *
 * @see hook_node_access_records()
 *
 * Upon viewing, editing or deleting a node, hook_node_grants() builds a
 * permissions array that is compared against the stored access records. The
 * user must have one or more matching permissions in order to complete the
 * requested operation.
 *
 * @see hook_node_grants()
 * @see hook_node_grants_alter()
 *
 * @param &$grants
 *   The $grants array returned by hook_node_access_records().
 * @param $node
 *   The node for which the grants were acquired.
 *
 * The preferred use of this hook is in a module that bridges multiple node
251 252
 * access modules with a configurable behavior, as shown in the example with the
 * 'is_preview' field.
253 254 255
 *
 * @ingroup node_access
 */
256
function hook_node_access_records_alter(&$grants, $node) {
257 258 259 260 261 262 263 264 265
  // Our module allows editors to mark specific articles with the 'is_preview'
  // field. If the node being saved has a TRUE value for that field, then only
  // our grants are retained, and other grants are removed. Doing so ensures
  // that our rules are enforced no matter what priority other grants are given.
  if ($node->is_preview) {
    // Our module grants are set in $grants['example'].
    $temp = $grants['example'];
    // Now remove all module grants but our own.
    $grants = array('example' => $temp);
266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309
  }
}

/**
 * Alter user access rules when trying to view, edit or delete a node.
 *
 * Node access modules establish rules for user access to content.
 * hook_node_grants() defines permissions for a user to view, edit or
 * delete nodes by building a $grants array that indicates the permissions
 * assigned to the user by each node access module. This hook is called to allow
 * modules to modify the $grants array by reference, so the interaction of
 * multiple node access modules can be altered or advanced business logic can be
 * applied.
 *
 * @see hook_node_grants()
 *
 * The resulting grants are then checked against the records stored in the
 * {node_access} table to determine if the operation may be completed.
 *
 * @see hook_node_access_records()
 * @see hook_node_access_records_alter()
 *
 * @param &$grants
 *   The $grants array returned by hook_node_grants().
 * @param $account
 *   The user account requesting access to content.
 * @param $op
 *   The operation being performed, 'view', 'update' or 'delete'.
 *
 * Developers may use this hook to either add additional grants to a user
 * or to remove existing grants. These rules are typically based on either the
 * permissions assigned to a user role, or specific attributes of a user
 * account.
 *
 * @ingroup node_access
 */
function hook_node_grants_alter(&$grants, $account, $op) {
  // Our sample module never allows certain roles to edit or delete
  // content. Since some other node access modules might allow this
  // permission, we expressly remove it by returning an empty $grants
  // array for roles specified in our variable setting.

  // Get our list of banned roles.
  $restricted = variable_get('example_restricted_roles', array());
310

311 312 313 314 315 316 317 318 319 320
  if ($op != 'view' && !empty($restricted)) {
    // Now check the roles for this account against the restrictions.
    foreach ($restricted as $role_id) {
      if (isset($user->roles[$role_id])) {
        $grants = array();
      }
    }
  }
}

321 322 323
/**
 * Add mass node operations.
 *
324 325 326 327 328
 * This hook enables modules to inject custom operations into the mass
 * operations dropdown found at admin/content, by associating a callback
 * function with the operation, which is called when the form is submitted. The
 * callback function receives one initial argument, which is an array of the
 * checked nodes.
329 330 331 332
 *
 * @return
 *   An array of operations. Each operation is an associative array that may
 *   contain the following key-value pairs:
333 334 335 336 337
 *   - 'label': Required. The label for the operation, displayed in the dropdown
 *     menu.
 *   - 'callback': Required. The function to call for the operation.
 *   - 'callback arguments': Optional. An array of additional arguments to pass
 *     to the callback function.
338 339 340
 */
function hook_node_operations() {
  $operations = array(
341 342 343 344
    'publish' => array(
      'label' => t('Publish selected content'),
      'callback' => 'node_mass_update',
      'callback arguments' => array('updates' => array('status' => NODE_PUBLISHED)),
345
    ),
346 347 348 349
    'unpublish' => array(
      'label' => t('Unpublish selected content'),
      'callback' => 'node_mass_update',
      'callback arguments' => array('updates' => array('status' => NODE_NOT_PUBLISHED)),
350
    ),
351 352 353 354
    'promote' => array(
      'label' => t('Promote selected content to front page'),
      'callback' => 'node_mass_update',
      'callback arguments' => array('updates' => array('status' => NODE_PUBLISHED, 'promote' => NODE_PROMOTED)),
355 356
    ),
    'demote' => array(
357 358 359
      'label' => t('Demote selected content from front page'),
      'callback' => 'node_mass_update',
      'callback arguments' => array('updates' => array('promote' => NODE_NOT_PROMOTED)),
360
    ),
361 362 363 364 365 366 367 368 369
    'sticky' => array(
      'label' => t('Make selected content sticky'),
      'callback' => 'node_mass_update',
      'callback arguments' => array('updates' => array('status' => NODE_PUBLISHED, 'sticky' => NODE_STICKY)),
    ),
    'unsticky' => array(
      'label' => t('Make selected content not sticky'),
      'callback' => 'node_mass_update',
      'callback arguments' => array('updates' => array('sticky' => NODE_NOT_STICKY)),
370 371
    ),
    'delete' => array(
372 373
      'label' => t('Delete selected content'),
      'callback' => NULL,
374 375 376 377 378
    ),
  );
  return $operations;
}

379
/**
380 381 382 383 384
 * Respond to node deletion.
 *
 * This hook is invoked from node_delete_multiple() after the node has been
 * removed from the node table in the database, after the type-specific
 * hook_delete() has been invoked, and before field_attach_delete() is called.
385 386 387
 *
 * @param $node
 *   The node that is being deleted.
388 389
 *
 * @ingroup node_api_hooks
390
 */
391
function hook_node_delete($node) {
392 393 394
  db_delete('mytable')
    ->condition('nid', $node->nid)
    ->execute();
395 396 397
}

/**
398
 * Respond to deletion of a node revision.
399
 *
400 401 402
 * This hook is invoked from node_revision_delete() after the revision has been
 * removed from the node_revision table, and before
 * field_attach_delete_revision() is called.
403 404
 *
 * @param $node
405
 *   The node revision (node object) that is being deleted.
406 407
 *
 * @ingroup node_api_hooks
408
 */
409
function hook_node_revision_delete($node) {
410 411 412 413 414 415 416 417 418 419
  db_delete('upload')->condition('vid', $node->vid)->execute();
  if (!is_array($node->files)) {
    return;
  }
  foreach ($node->files as $file) {
    file_delete($file);
  }
}

/**
420
 * Respond to creation of a new node.
421
 *
422 423 424
 * This hook is invoked from node_save() after the node is inserted into the
 * node table in the database, after the type-specific hook_insert() is invoked,
 * and after field_attach_insert() is called.
425 426
 *
 * @param $node
427
 *   The node that is being created.
428 429
 *
 * @ingroup node_api_hooks
430
 */
431
function hook_node_insert($node) {
432 433 434 435 436 437
  db_insert('mytable')
    ->fields(array(
      'nid' => $node->nid,
      'extra' => $node->extra,
    ))
    ->execute();
438 439
}

440
/**
441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460
 * Act on nodes being loaded from the database.
 *
 * This hook is invoked during node loading, which is handled by entity_load(),
 * via classes NodeController and DrupalDefaultEntityController. After the node
 * information is read from the database or the entity cache, hook_load() is
 * invoked on the node's content type module, then field_attach_node_revision()
 * or field_attach_load() is called, then hook_entity_load() is invoked on all
 * implementing modules, and finally hook_node_load() is invoked on all
 * implementing modules.
 *
 * This hook should only be used to add information that is not in the node or
 * node revisions table, not to replace information that is in these tables
 * (which could interfere with the entity cache). For performance reasons,
 * information for all available nodes should be loaded in a single query where
 * possible.
 *
 * The $types parameter allows for your module to have an early return (for
 * efficiency) if your module only supports certain node types. However, if your
 * module defines a content type, you can use hook_load() to respond to loading
 * of just that content type.
461 462
 *
 * @param $nodes
463
 *   An array of the nodes being loaded, keyed by nid.
464 465
 * @param $types
 *   An array containing the types of the nodes.
466 467
 *
 * For a detailed usage example, see nodeapi_example.module.
468 469
 *
 * @ingroup node_api_hooks
470
 */
471
function hook_node_load($nodes, $types) {
472
  $result = db_query('SELECT nid, foo FROM {mytable} WHERE nid IN(:nids)', array(':nids' => array_keys($nodes)));
473 474 475 476 477
  foreach ($result as $record) {
    $nodes[$record->nid]->foo = $record->foo;
  }
}

478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507
/**
 * Control access to a node.
 *
 * Modules may implement this hook if they want to have a say in whether or not
 * a given user has access to perform a given operation on a node.
 *
 * The administrative account (user ID #1) always passes any access check,
 * so this hook is not called in that case. Users with the "bypass node access"
 * permission may always view and edit content through the administrative
 * interface.
 *
 * Note that not all modules will want to influence access on all
 * node types. If your module does not want to actively grant or
 * block access, return NODE_ACCESS_IGNORE or simply return nothing.
 * Blindly returning FALSE will break other node access modules.
 *
 * @link http://api.drupal.org/api/group/node_access/7 More on the node access system @endlink
 * @ingroup node_access
 * @param $node
 *   The node on which the operation is to be performed, or, if it does
 *   not yet exist, the type of node to be created.
 * @param $op
 *   The operation to be performed. Possible values:
 *   - "create"
 *   - "delete"
 *   - "update"
 *   - "view"
 * @param $account
 *   A user object representing the user for whom the operation is to be
 *   performed.
508
 *
509 510 511 512 513 514
 * @return
 *   NODE_ACCESS_ALLOW if the operation is to be allowed;
 *   NODE_ACCESS_DENY if the operation is to be denied;
 *   NODE_ACCESSS_IGNORE to not affect this operation at all.
 */
function hook_node_access($node, $op, $account) {
515
  $type = is_string($node) ? $node : $node->type;
516

517
  if (in_array($type, node_permissions_get_configured_types())) {
518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539
    if ($op == 'create' && user_access('create ' . $type . ' content', $account)) {
      return NODE_ACCESS_ALLOW;
    }

    if ($op == 'update') {
      if (user_access('edit any ' . $type . ' content', $account) || (user_access('edit own ' . $type . ' content', $account) && ($account->uid == $node->uid))) {
        return NODE_ACCESS_ALLOW;
      }
    }

    if ($op == 'delete') {
      if (user_access('delete any ' . $type . ' content', $account) || (user_access('delete own ' . $type . ' content', $account) && ($account->uid == $node->uid))) {
        return NODE_ACCESS_ALLOW;
      }
    }
  }

  // Returning nothing from this function would have the same effect.
  return NODE_ACCESS_IGNORE;
}


540
/**
541 542 543 544
 * Act on a node object about to be shown on the add/edit form.
 *
 * This hook is invoked from node_object_prepare() after the type-specific
 * hook_prepare() is invoked.
545
 *
546
 * @param $node
547
 *   The node that is about to be shown on the add/edit form.
548 549
 *
 * @ingroup node_api_hooks
550
 */
551
function hook_node_prepare($node) {
552
  if (!isset($node->comment)) {
553
    $node->comment = variable_get("comment_$node->type", COMMENT_NODE_OPEN);
554 555 556 557
  }
}

/**
558
 * Act on a node object being cloned for translation.
559
 *
560 561 562
 * This hook is invoked from translation_node_prepare() after the node is
 * loaded. $node->language is set to the language being requested, and
 * $node->translation_source is set to the node object being cloned.
563
 *
564
 * @param $node
565
 *   The node object being prepared for translation.
566 567
 *
 * @ingroup node_api_hooks
568
 */
569
function hook_node_prepare_translation($node) {
570 571 572
}

/**
573
 * Act on a node being displayed as a search result.
574
 *
575
 * This hook is invoked from node_search_execute(), after node_load()
576
 * and node_view() have been called.
577 578
 *
 * @param $node
579 580
 *   The node being displayed in a search result.
 *
581 582
 * @return
 *   Extra information to be displayed with search result.
583 584
 *
 * @ingroup node_api_hooks
585
 */
586
function hook_node_search_result($node) {
587 588 589 590 591
  $comments = db_query('SELECT comment_count FROM {node_comment_statistics} WHERE nid = :nid', array('nid' => $node->nid))->fetchField();
  return format_plural($comments, '1 comment', '@count comments');
}

/**
592
 * Act on a node being inserted or updated.
593
 *
594 595
 * This hook is invoked from node_save() before the node is saved to the
 * database.
596 597
 *
 * @param $node
598
 *   The node that is being inserted or updated.
599 600
 *
 * @ingroup node_api_hooks
601
 */
602
function hook_node_presave($node) {
603 604 605 606 607 608 609 610 611
  if ($node->nid && $node->moderate) {
    // Reset votes when node is updated:
    $node->score = 0;
    $node->users = '';
    $node->votes = 0;
  }
}

/**
612 613 614 615 616
 * Respond to updates to a node.
 *
 * This hook is invoked from node_save() after the node is updated in the node
 * table in the database, after the type-specific hook_update() is invoked, and
 * after field_attach_update() is called.
617 618
 *
 * @param $node
619
 *   The node that is being updated.
620 621
 *
 * @ingroup node_api_hooks
622
 */
623
function hook_node_update($node) {
624 625 626 627
  db_update('mytable')
    ->fields(array('extra' => $node->extra))
    ->condition('nid', $node->nid)
    ->execute();
628 629 630
}

/**
631
 * Act on a node being indexed for searching.
632
 *
633
 * This hook is invoked during search indexing, after node_load(), and after
634
 * the result of node_view() is added as $node->rendered to the node object.
635 636
 *
 * @param $node
637 638
 *   The node being indexed.
 *
639 640
 * @return
 *   Array of additional information to be indexed.
641 642
 *
 * @ingroup node_api_hooks
643
 */
644
function hook_node_update_index($node) {
645 646 647
  $text = '';
  $comments = db_query('SELECT subject, comment, format FROM {comment} WHERE nid = :nid AND status = :status', array(':nid' => $node->nid, ':status' => COMMENT_PUBLISHED));
  foreach ($comments as $comment) {
648
    $text .= '<h2>' . check_plain($comment->subject) . '</h2>' . check_markup($comment->comment, $comment->format, '', TRUE);
649 650 651 652 653
  }
  return $text;
}

/**
654 655 656 657 658 659
 * Perform node validation before a node is created or updated.
 *
 * This hook is invoked from node_validate(), after a user has has finished
 * editing the node and is previewing or submitting it. It is invoked at the
 * end of all the standard validation steps, and after the type-specific
 * hook_validate() is invoked.
660
 *
661 662 663 664 665 666
 * To indicate a validation error, use form_set_error().
 *
 * Note: Changes made to the $node object within your hook implementation will
 * have no effect.  The preferred method to change a node's content is to use
 * hook_node_presave() instead. If it is really necessary to change
 * the node at the validate stage, you can use form_set_value().
667 668
 *
 * @param $node
669
 *   The node being validated.
670
 * @param $form
671
 *   The form being used to edit the node.
672 673
 *
 * @ingroup node_api_hooks
674
 */
675
function hook_node_validate($node, $form) {
676 677 678 679 680 681 682 683
  if (isset($node->end) && isset($node->start)) {
    if ($node->start > $node->end) {
      form_set_error('time', t('An event may not end before it starts.'));
    }
  }
}

/**
684
 * Act on a node that is being assembled before rendering.
685
 *
686 687 688 689
 * The module may add elements to $node->content prior to rendering. This hook
 * will be called after hook_view(). The structure of $node->content is a
 * renderable array as expected by drupal_render().
 *
690
 * When $view_mode is 'rss', modules can also add extra RSS elements and
691 692 693
 * namespaces to $node->rss_elements and $node->rss_namespaces respectively for
 * the RSS item generated for this node.
 * For details on how this is used @see node_feed()
694 695 696 697
 *
 * @see taxonomy_node_view()
 * @see upload_node_view()
 * @see comment_node_view()
698 699
 *
 * @param $node
700
 *   The node that is being assembled for rendering.
701 702
 * @param $view_mode
 *   The $view_mode parameter from node_view().
703 704
 *
 * @ingroup node_api_hooks
705
 */
706
function hook_node_view($node, $view_mode) {
707
  $node->content['my_additional_field'] = array(
708
    '#markup' => $additional_field,
709
    '#weight' => 10,
710
    '#theme' => 'mymodule_my_additional_field',
711
  );
712 713
}

714
/**
715
 * Alter the results of node_view().
716
 *
717 718 719
 * This hook is called after the content has been assembled in a structured
 * array and may be used for doing processing which requires that the complete
 * node content structure has been built.
720 721
 *
 * If the module wishes to act on the rendered HTML of the node rather than the
722 723
 * structured content array, it may use this hook to add a #post_render
 * callback.  Alternatively, it could also implement hook_preprocess_node(). See
724 725
 * drupal_render() and theme() documentation respectively for details.
 *
726 727 728
 * @param $build
 *   A renderable array representing the node content.
 *
729
 * @see node_view()
730 731
 *
 * @ingroup node_api_hooks
732
 */
733
function hook_node_view_alter(&$build) {
734
  if ($build['#view_mode'] == 'full' && isset($build['an_additional_field'])) {
735
    // Change its weight.
736
    $build['an_additional_field']['#weight'] = -10;
737
  }
738 739

  // Add a #post_render callback to act on the rendered HTML of the node.
740
  $build['#post_render'][] = 'my_module_node_post_render';
741 742
}

743
/**
744
 * Define module-provided node types.
745
 *
746 747 748 749
 * This hook allows a module to define one or more of its own node types. For
 * example, the blog module uses it to define a blog node-type named "Blog
 * entry." The name and attributes of each desired node type are specified in
 * an array returned by the hook.
750
 *
751 752 753 754 755 756
 * Only module-provided node types should be defined through this hook. User-
 * provided (or 'custom') node types should be defined only in the 'node_type'
 * database table, and should be maintained by using the node_type_save() and
 * node_type_delete() functions.
 *
 * @return
757 758 759 760
 *   An array of information defining the module's node types. The array
 *   contains a sub-array for each node type, with the machine-readable type
 *   name as the key. Each sub-array has up to 10 attributes. Possible
 *   attributes:
761
 *   - "name": the human-readable name of the node type. Required.
762 763 764
 *   - "base": the base string used to construct callbacks corresponding to
 *      this node type.
 *      (i.e. if base is defined as example_foo, then example_foo_insert will
765
 *      be called when inserting a node of that type). This string is usually
766
 *      the name of the module, but not always. Required.
767
 *   - "description": a brief description of the node type. Required.
768 769
 *   - "help": help information shown to the user when creating a node of
 *      this type.. Optional (defaults to '').
770 771 772 773
 *   - "has_title": boolean indicating whether or not this node type has a title
 *      field. Optional (defaults to TRUE).
 *   - "title_label": the label for the title field of this content type.
 *      Optional (defaults to 'Title').
774
 *   - "has_body": boolean indicating whether or not this node type has a body
775 776 777
 *      field. Optional (defaults to TRUE).
 *   - "body_label": the label for the body field of this content type. Optional
 *      (defaults to 'Body').
778
 *   - "locked": boolean indicating whether the administrator can change the
779 780
 *      machine name of this type. FALSE = changeable (not locked),
 *      TRUE = unchangeable (locked). Optional (defaults to TRUE).
781 782 783
 *
 * The machine-readable name of a node type should contain only letters,
 * numbers, and underscores. Underscores will be converted into hyphens for the
784
 * purpose of constructing URLs.
785 786 787 788 789 790
 *
 * All attributes of a node type that are defined through this hook (except for
 * 'locked') can be edited by a site administrator. This includes the
 * machine-readable name of a node type, if 'locked' is set to FALSE.
 *
 * For a detailed usage example, see node_example.module.
791 792
 *
 * @ingroup node_api_hooks
793 794 795
 */
function hook_node_info() {
  return array(
796 797 798 799
    'blog' => array(
      'name' => t('Blog entry'),
      'base' => 'blog',
      'description' => t('Use for multi-user blogs. Every user gets a personal blog.'),
800 801 802 803
    )
  );
}

804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840
/**
 * Provide additional methods of scoring for core search results for nodes.
 *
 * A node's search score is used to rank it among other nodes matched by the
 * search, with the highest-ranked nodes appearing first in the search listing.
 *
 * For example, a module allowing users to vote on content could expose an
 * option to allow search results' rankings to be influenced by the average
 * voting score of a node.
 *
 * All scoring mechanisms are provided as options to site administrators, and
 * may be tweaked based on individual sites or disabled altogether if they do
 * not make sense. Individual scoring mechanisms, if enabled, are assigned a
 * weight from 1 to 10. The weight represents the factor of magnification of
 * the ranking mechanism, with higher-weighted ranking mechanisms having more
 * influence. In order for the weight system to work, each scoring mechanism
 * must return a value between 0 and 1 for every node. That value is then
 * multiplied by the administrator-assigned weight for the ranking mechanism,
 * and then the weighted scores from all ranking mechanisms are added, which
 * brings about the same result as a weighted average.
 *
 * @return
 *   An associative array of ranking data. The keys should be strings,
 *   corresponding to the internal name of the ranking mechanism, such as
 *   'recent', or 'comments'. The values should be arrays themselves, with the
 *   following keys available:
 *   - "title": the human readable name of the ranking mechanism. Required.
 *   - "join": part of a query string to join to any additional necessary
 *     table. This is not necessary if the table required is already joined to
 *     by the base query, such as for the {node} table. Other tables should use
 *     the full table name as an alias to avoid naming collisions. Optional.
 *   - "score": part of a query string to calculate the score for the ranking
 *     mechanism based on values in the database. This does not need to be
 *     wrapped in parentheses, as it will be done automatically; it also does
 *     not need to take the weighted system into account, as it will be done
 *     automatically. It does, however, need to calculate a decimal between
 *     0 and 1; be careful not to cast the entire score to an integer by
841
 *     inadvertently introducing a variable argument. Required.
842 843
 *   - "arguments": if any arguments are required for the score, they can be
 *     specified in an array here.
844 845
 *
 * @ingroup node_api_hooks
846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866
 */
function hook_ranking() {
  // If voting is disabled, we can avoid returning the array, no hard feelings.
  if (variable_get('vote_node_enabled', TRUE)) {
    return array(
      'vote_average' => array(
        'title' => t('Average vote'),
        // Note that we use i.sid, the search index's search item id, rather than
        // n.nid.
        'join' => 'LEFT JOIN {vote_node_data} vote_node_data ON vote_node_data.nid = i.sid',
        // The highest possible score should be 1, and the lowest possible score,
        // always 0, should be 0.
        'score' => 'vote_node_data.average / CAST(%f AS DECIMAL)',
        // Pass in the highest possible voting score as a decimal argument.
        'arguments' => array(variable_get('vote_score_max', 5)),
      ),
    );
  }
}


867
/**
868
 * Respond to node type creation.
869
 *
870 871
 * This hook is invoked from node_type_save() after the node type is added
 * to the database.
872 873
 *
 * @param $info
874
 *   The node type object that is being created.
875 876 877 878
 */
function hook_node_type_insert($info) {
}

879
/**
880
 * Respond to node type updates.
881
 *
882 883
 * This hook is invoked from node_type_save() after the node type is updated
 * in the database.
884 885
 *
 * @param $info
886
 *   The node type object that is being updated.
887
 */
888 889 890 891 892
function hook_node_type_update($info) {
  if (!empty($info->old_type) && $info->old_type != $info->type) {
    $setting = variable_get('comment_' . $info->old_type, COMMENT_NODE_OPEN);
    variable_del('comment_' . $info->old_type);
    variable_set('comment_' . $info->type, $setting);
893 894 895
  }
}

896
/**
897
 * Respond to node type deletion.
898
 *
899 900
 * This hook is invoked from node_type_delete() after the node type is removed
 * from the database.
901 902
 *
 * @param $info
903
 *   The node type object that is being deleted.
904 905 906 907 908
 */
function hook_node_type_delete($info) {
  variable_del('comment_' . $info->type);
}

909 910 911
/**
 * Respond to node deletion.
 *
912 913
 * This hook is invoked only on the module that defines the node's content type
 * (use hook_node_delete() to respond to all node deletions).
914
 *
915 916 917
 * This hook is invoked from node_delete_multiple() after the node has been
 * removed from the node table in the database, before hook_node_delete() is
 * invoked, and before field_attach_delete() is called.
918
 *
919 920
 * @param $node
 *   The node that is being deleted.
921 922
 *
 * @ingroup node_api_hooks
923
 */
924
function hook_delete($node) {
925 926 927
  db_delete('mytable')
    ->condition('nid', $nid->nid)
    ->execute();
928 929 930
}

/**
931
 * Act on a node object about to be shown on the add/edit form.
932
 *
933 934
 * This hook is invoked only on the module that defines the node's content type
 * (use hook_node_prepare() to act on all node preparations).
935
 *
936 937 938 939 940
 * This hook is invoked from node_object_prepare() before the general
 * hook_node_prepare() is invoked.
 *
 * @param $node
 *   The node that is about to be shown on the add/edit form.
941 942
 *
 * @ingroup node_api_hooks
943
 */
944
function hook_prepare($node) {
945 946 947
  if ($file = file_check_upload($field_name)) {
    $file = file_save_upload($field_name, _image_filename($file->filename, NULL, TRUE));
    if ($file) {
948
      if (!image_get_info($file->uri)) {
949 950 951 952 953 954 955
        form_set_error($field_name, t('Uploaded file is not a valid image'));
        return;
      }
    }
    else {
      return;
    }
956
    $node->images['_original'] = $file->uri;
957
    _image_build_derivatives($node, TRUE);
958 959 960 961 962 963 964 965 966 967 968
    $node->new_file = TRUE;
  }
}

/**
 * Display a node editing form.
 *
 * This hook, implemented by node modules, is called to retrieve the form
 * that is displayed when one attempts to "create/edit" an item. This form is
 * displayed at the URI http://www.example.com/?q=node/<add|edit>/nodetype.
 *
969
 * @param $node
970 971 972 973 974 975 976 977 978 979 980 981 982
 *   The node being added or edited.
 * @param $form_state
 *   The form state array. Changes made to this variable will have no effect.
 * @return
 *   An array containing the form elements to be displayed in the node
 *   edit form.
 *
 * The submit and preview buttons, taxonomy controls, and administrative
 * accoutrements are displayed automatically by node.module. This hook
 * needs to return the node title, the body text area, and fields
 * specific to the node type.
 *
 * For a detailed usage example, see node_example.module.
983 984
 *
 * @ingroup node_api_hooks
985
 */
986
function hook_form($node, $form_state) {
987
  $type = node_type_get_type($node);
988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014

  $form['title'] = array(
    '#type' => 'textfield',
    '#title' => check_plain($type->title_label),
    '#required' => TRUE,
  );
  $form['body'] = array(
    '#type' => 'textarea',
    '#title' => check_plain($type->body_label),
    '#rows' => 20,
    '#required' => TRUE,
  );
  $form['field1'] = array(
    '#type' => 'textfield',
    '#title' => t('Custom field'),
    '#default_value' => $node->field1,
    '#maxlength' => 127,
  );
  $form['selectbox'] = array(
    '#type' => 'select',
    '#title' => t('Select box'),
    '#default_value' => $node->selectbox,
    '#options' => array(
      1 => 'Option A',
      2 => 'Option B',
      3 => 'Option C',
    ),
1015
    '#description' => t('Choose an option.'),
1016 1017 1018 1019 1020 1021
  );

  return $form;
}

/**
1022
 * Respond to creation of a new node.
1023
 *
1024 1025
 * This hook is invoked only on the module that defines the node's content type
 * (use hook_node_insert() to act on all node insertions).
1026
 *
1027 1028 1029
 * This hook is invoked from node_save() after the node is inserted into the
 * node table in the database, before field_attach_insert() is called, and
 * before hook_node_insert() is invoked.
1030
 *
1031 1032
 * @param $node
 *   The node that is being created.
1033 1034
 *
 * @ingroup node_api_hooks
1035
 */
1036
function hook_insert($node) {
1037 1038 1039 1040 1041 1042
  db_insert('mytable')
    ->fields(array(
      'nid' => $node->nid,
      'extra' => $node->extra,
    ))
    ->execute();
1043 1044 1045
}

/**
1046
 * Act on nodes being loaded from the database.
1047
 *
1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063
 * This hook is invoked only on the module that defines the node's content type
 * (use hook_node_load() to respond to all node loads).
 *
 * This hook is invoked during node loading, which is handled by entity_load(),
 * via classes NodeController and DrupalDefaultEntityController. After the node
 * information is read from the database or the entity cache, hook_load() is
 * invoked on the node's content type module, then field_attach_node_revision()
 * or field_attach_load() is called, then hook_entity_load() is invoked on all
 * implementing modules, and finally hook_node_load() is invoked on all
 * implementing modules.
 *
 * This hook should only be used to add information that is not in the node or
 * node revisions table, not to replace information that is in these tables
 * (which could interfere with the entity cache). For performance reasons,
 * information for all available nodes should be loaded in a single query where
 * possible.
1064
 *
1065
 * @param $nodes
1066
 *   An array of the nodes being loaded, keyed by nid.
1067 1068
 *
 * For a detailed usage example, see node_example.module.
1069 1070
 *
 * @ingroup node_api_hooks
1071
 */
1072
function hook_load($nodes) {
1073
  $result = db_query('SELECT nid, foo FROM {mytable} WHERE nid IN (:nids)', array(':nids' => array_keys($nodes)));
1074 1075 1076
  foreach ($result as $record) {
    $nodes[$record->nid]->foo = $record->foo;
  }
1077 1078 1079
}

/**
1080
 * Respond to updates to a node.
1081
 *
1082 1083
 * This hook is invoked only on the module that defines the node's content type
 * (use hook_node_update() to act on all node updates).
1084
 *
1085 1086 1087
 * This hook is invoked from node_save() after the node is updated in the
 * node table in the database, before field_attach_update() is called, and
 * before hook_node_update() is invoked.
1088
 *
1089 1090
 * @param $node
 *   The node that is being updated.
1091 1092
 *
 * @ingroup node_api_hooks
1093
 */
1094
function hook_update($node) {
1095 1096 1097 1098
  db_update('mytable')
    ->fields(array('extra' => $node->extra))
    ->condition('nid', $node->nid)
    ->execute();
1099 1100 1101
}

/**
1102
 * Perform node validation before a node is created or updated.
1103
 *
1104 1105
 * This hook is invoked only on the module that defines the node's content type
 * (use hook_node_validate() to act on all node validations).
1106
 *
1107
 * This hook is invoked from node_validate(), after a user has finished
1108 1109 1110
 * editing the node and is previewing or submitting it. It is invoked at the end
 * of all the standard validation steps, and before hook_node_validate() is
 * invoked.
1111
 *
1112
 * To indicate a validation error, use form_set_error().
1113
 *
1114 1115
 * Note: Changes made to the $node object within your hook implementation will
 * have no effect.  The preferred method to change a node's content is to use
1116
 * hook_node_presave() instead.
1117
 *
1118 1119 1120 1121
 * @param $node
 *   The node being validated.
 * @param $form
 *   The form being used to edit the node.
1122 1123
 *
 * @ingroup node_api_hooks
1124
 */