1 <?php

     2 

     3 /**

     4  * @file

     5  * Hooks provided by the Node module.

     6  */

     7 

     8 /**

     9  * @defgroup node_api_hooks Node API Hooks

    10  * @{

    11  * Functions to define and modify content types.

    12  *

    13  * Each content type is maintained by a primary module, which is either

    14  * node.module (for content types created in the user interface) or the module

    15  * that implements hook_node_info() to define the content type.

    16  *

    17  * During node operations (create, update, view, delete, etc.), there are

    18  * several sets of hooks that get invoked to allow modules to modify the base

    19  * node operation:

    20  * - Node-type-specific hooks: When defining a node type, hook_node_info()

    21  *   returns a 'base' component. Node-type-specific hooks are named

    22  *   base_hookname() instead of mymodule_hookname() (in a module called

    23  *   'mymodule' for example). Only the node type's corresponding implementation

    24  *   is invoked. For example, poll_node_info() in poll.module defines the base

    25  *   for the 'poll' node type as 'poll'. So when a poll node is created,

    26  *   hook_insert() is invoked on poll_insert() only.

    27  *   Hooks that are node-type-specific are noted below.

    28  * - All-module hooks: This set of hooks is invoked on all implementing modules,

    29  *   to allow other modules to modify what the primary node module is doing. For

    30  *   example, hook_node_insert() is invoked on all modules when creating a poll

    31  *   node.

    32  * - Field hooks: Hooks related to the fields attached to the node. These are

    33  *   invoked from the field operations functions described below, and can be

    34  *   either field-type-specific or all-module hooks.

    35  * - Entity hooks: Generic hooks for "entity" operations. These are always

    36  *   invoked on all modules.

    37  *

    38  * Here is a list of the node and entity hooks that are invoked, field

    39  * operations, and other steps that take place during node operations:

    40  * - Creating a new node (calling node_save() on a new node):

    41  *   - field_attach_presave()

    42  *   - hook_node_presave() (all)

    43  *   - hook_entity_presave() (all)

    44  *   - Node and revision records are written to the database

    45  *   - hook_insert() (node-type-specific)

    46  *   - field_attach_insert()

    47  *   - hook_node_insert() (all)

    48  *   - hook_entity_insert() (all)

    49  *   - hook_node_access_records() (all)

    50  *   - hook_node_access_records_alter() (all)

    51  * - Updating an existing node (calling node_save() on an existing node):

    52  *   - field_attach_presave()

    53  *   - hook_node_presave() (all)

    54  *   - hook_entity_presave() (all)

    55  *   - Node and revision records are written to the database

    56  *   - hook_update() (node-type-specific)

    57  *   - field_attach_update()

    58  *   - hook_node_update() (all)

    59  *   - hook_entity_update() (all)

    60  *   - hook_node_access_records() (all)

    61  *   - hook_node_access_records_alter() (all)

    62  * - Loading a node (calling node_load(), node_load_multiple() or entity_load()

    63  *   with $entity_type of 'node'):

    64  *   - Node and revision information is read from database.

    65  *   - hook_load() (node-type-specific)

    66  *   - field_attach_load_revision() and field_attach_load()

    67  *   - hook_entity_load() (all)

    68  *   - hook_node_load() (all)

    69  * - Viewing a single node (calling node_view() - note that the input to

    70  *   node_view() is a loaded node, so the Loading steps above are already done):

    71  *   - hook_view() (node-type-specific)

    72  *   - field_attach_prepare_view()

    73  *   - hook_entity_prepare_view() (all)

    74  *   - field_attach_view()

    75  *   - hook_node_view() (all)

    76  *   - hook_entity_view() (all)

    77  *   - hook_node_view_alter() (all)

    78  *   - hook_entity_view_alter() (all)

    79  * - Viewing multiple nodes (calling node_view_multiple() - note that the input

    80  *   to node_view_multiple() is a set of loaded nodes, so the Loading steps

    81  *   above are already done):

    82  *   - field_attach_prepare_view()

    83  *   - hook_entity_prepare_view() (all)

    84  *   - hook_view() (node-type-specific)

    85  *   - field_attach_view()

    86  *   - hook_node_view() (all)

    87  *   - hook_entity_view() (all)

    88  *   - hook_node_view_alter() (all)

    89  *   - hook_entity_view_alter() (all)

    90  * - Deleting a node (calling node_delete() or node_delete_multiple()):

    91  *   - Node is loaded (see Loading section above)

    92  *   - hook_delete() (node-type-specific)

    93  *   - hook_node_delete() (all)

    94  *   - hook_entity_delete() (all)

    95  *   - field_attach_delete()

    96  *   - Node and revision information are deleted from database

    97  * - Deleting a node revision (calling node_revision_delete()):

    98  *   - Node is loaded (see Loading section above)

    99  *   - Revision information is deleted from database

   100  *   - hook_node_revision_delete() (all)

   101  *   - field_attach_delete_revision()

   102  * - Preparing a node for editing (calling node_form() - note that if it is an

   103  *   existing node, it will already be loaded; see the Loading section above):

   104  *   - hook_prepare() (node-type-specific)

   105  *   - hook_node_prepare() (all)

   106  *   - hook_form() (node-type-specific)

   107  *   - field_attach_form()

   108  * - Validating a node during editing form submit (calling

   109  *   node_form_validate()):

   110  *   - hook_validate() (node-type-specific)

   111  *   - hook_node_validate() (all)

   112  *   - field_attach_form_validate()

   113  * - Searching (calling node_search_execute()):

   114  *   - hook_ranking() (all)

   115  *   - Query is executed to find matching nodes

   116  *   - Resulting node is loaded (see Loading section above)

   117  *   - Resulting node is prepared for viewing (see Viewing a single node above)

   118  *   - comment_node_update_index() is called.

   119  *   - hook_node_search_result() (all)

   120  * - Search indexing (calling node_update_index()):

   121  *   - Node is loaded (see Loading section above)

   122  *   - Node is prepared for viewing (see Viewing a single node above)

   123  *   - hook_node_update_index() (all)

   124  * @}

   125  */

   126 

   127 /**

   128  * @addtogroup hooks

   129  * @{

   130  */

   131 

   132 /**

   133  * Inform the node access system what permissions the user has.

   134  *

   135  * This hook is for implementation by node access modules. In this hook,

   136  * the module grants a user different "grant IDs" within one or more

   137  * "realms". In hook_node_access_records(), the realms and grant IDs are

   138  * associated with permission to view, edit, and delete individual nodes.

   139  *

   140  * The realms and grant IDs can be arbitrarily defined by your node access

   141  * module; it is common to use role IDs as grant IDs, but that is not required.

   142  * Your module could instead maintain its own list of users, where each list has

   143  * an ID. In that case, the return value of this hook would be an array of the

   144  * list IDs that this user is a member of.

   145  *

   146  * A node access module may implement as many realms as necessary to properly

   147  * define the access privileges for the nodes. Note that the system makes no

   148  * distinction between published and unpublished nodes. It is the module's

   149  * responsibility to provide appropriate realms to limit access to unpublished

   150  * content.

   151  *

   152  * Node access records are stored in the {node_access} table and define which

   153  * grants are required to access a node. There is a special case for the view

   154  * operation -- a record with node ID 0 corresponds to a "view all" grant for

   155  * the realm and grant ID of that record. If there are no node access modules

   156  * enabled, the core node module adds a node ID 0 record for realm 'all'. Node

   157  * access modules can also grant "view all" permission on their custom realms;

   158  * for example, a module could create a record in {node_access} with:

   159  * @code

   160  * $record = array(

   161  *   'nid' => 0,

   162  *   'gid' => 888,

   163  *   'realm' => 'example_realm',

   164  *   'grant_view' => 1,

   165  *   'grant_update' => 0,

   166  *   'grant_delete' => 0,

   167  * );

   168  * drupal_write_record('node_access', $record);

   169  * @endcode

   170  * And then in its hook_node_grants() implementation, it would need to return:

   171  * @code

   172  * if ($op == 'view') {

   173  *   $grants['example_realm'] = array(888);

   174  * }

   175  * @endcode

   176  * If you decide to do this, be aware that the node_access_rebuild() function

   177  * will erase any node ID 0 entry when it is called, so you will need to make

   178  * sure to restore your {node_access} record after node_access_rebuild() is

   179  * called.

   180  *

   181  * @see node_access_view_all_nodes()

   182  * @see node_access_rebuild()

   183  *

   184  * @param $account

   185  *   The user object whose grants are requested.

   186  * @param $op

   187  *   The node operation to be performed, such as 'view', 'update', or 'delete'.

   188  *

   189  * @return

   190  *   An array whose keys are "realms" of grants, and whose values are arrays of

   191  *   the grant IDs within this realm that this user is being granted.

   192  *

   193  * For a detailed example, see node_access_example.module.

   194  *

   195  * @ingroup node_access

   196  */

   197 function hook_node_grants($account, $op) {

   198   if (user_access('access private content', $account)) {

   199     $grants['example'] = array(1);

   200   }

   201   $grants['example_author'] = array($account->uid);

   202   return $grants;

   203 }

   204 

   205 /**

   206  * Set permissions for a node to be written to the database.

   207  *

   208  * When a node is saved, a module implementing hook_node_access_records() will

   209  * be asked if it is interested in the access permissions for a node. If it is

   210  * interested, it must respond with an array of permissions arrays for that

   211  * node.

   212  *

   213  * Node access grants apply regardless of the published or unpublished status

   214  * of the node. Implementations must make sure not to grant access to

   215  * unpublished nodes if they don't want to change the standard access control

   216  * behavior. Your module may need to create a separate access realm to handle

   217  * access to unpublished nodes.

   218  *

   219  * Note that the grant values in the return value from your hook must be

   220  * integers and not boolean TRUE and FALSE.

   221  *

   222  * Each permissions item in the array is an array with the following elements:

   223  * - 'realm': The name of a realm that the module has defined in

   224  *   hook_node_grants().

   225  * - 'gid': A 'grant ID' from hook_node_grants().

   226  * - 'grant_view': If set to 1 a user that has been identified as a member

   227  *   of this gid within this realm can view this node. This should usually be

   228  *   set to $node->status. Failure to do so may expose unpublished content

   229  *   to some users.

   230  * - 'grant_update': If set to 1 a user that has been identified as a member

   231  *   of this gid within this realm can edit this node.

   232  * - 'grant_delete': If set to 1 a user that has been identified as a member

   233  *   of this gid within this realm can delete this node.

   234  * - 'priority': If multiple modules seek to set permissions on a node, the

   235  *   realms that have the highest priority will win out, and realms with a lower

   236  *   priority will not be written. If there is any doubt, it is best to

   237  *   leave this 0.

   238  *

   239  *

   240  * When an implementation is interested in a node but want to deny access to

   241  * everyone, it may return a "deny all" grant:

   242  *

   243  * @code

   244  * $grants[] = array(

   245  *   'realm' => 'all',

   246  *   'gid' => 0,

   247  *   'grant_view' => 0,

   248  *   'grant_update' => 0,

   249  *   'grant_delete' => 0,

   250  *   'priority' => 1,

   251  * );

   252  * @endcode

   253  *

   254  * Setting the priority should cancel out other grants. In the case of a

   255  * conflict between modules, it is safer to use hook_node_access_records_alter()

   256  * to return only the deny grant.

   257  *

   258  * Note: a deny all grant is not written to the database; denies are implicit.

   259  *

   260  * @see node_access_write_grants()

   261  *

   262  * @param $node

   263  *   The node that has just been saved.

   264  *

   265  * @return

   266  *   An array of grants as defined above.

   267  *

   268  * @see hook_node_access_records_alter()

   269  * @ingroup node_access

   270  */

   271 function hook_node_access_records($node) {

   272   // We only care about the node if it has been marked private. If not, it is

   273   // treated just like any other node and we completely ignore it.

   274   if ($node->private) {

   275     $grants = array();

   276     // Only published nodes should be viewable to all users. If we allow access

   277     // blindly here, then all users could view an unpublished node.

   278     if ($node->status) {

   279       $grants[] = array(

   280         'realm' => 'example',

   281         'gid' => 1,

   282         'grant_view' => 1,

   283         'grant_update' => 0,

   284         'grant_delete' => 0,

   285         'priority' => 0,

   286       );

   287     }

   288     // For the example_author array, the GID is equivalent to a UID, which

   289     // means there are many groups of just 1 user.

   290     // Note that an author can always view his or her nodes, even if they

   291     // have status unpublished.

   292     $grants[] = array(

   293       'realm' => 'example_author',

   294       'gid' => $node->uid,

   295       'grant_view' => 1,

   296       'grant_update' => 1,

   297       'grant_delete' => 1,

   298       'priority' => 0,

   299     );

   300 

   301     return $grants;

   302   }

   303 }

   304 

   305 /**

   306  * Alter permissions for a node before it is written to the database.

   307  *

   308  * Node access modules establish rules for user access to content. Node access

   309  * records are stored in the {node_access} table and define which permissions

   310  * are required to access a node. This hook is invoked after node access modules

   311  * returned their requirements via hook_node_access_records(); doing so allows

   312  * modules to modify the $grants array by reference before it is stored, so

   313  * custom or advanced business logic can be applied.

   314  *

   315  * @see hook_node_access_records()

   316  *

   317  * Upon viewing, editing or deleting a node, hook_node_grants() builds a

   318  * permissions array that is compared against the stored access records. The

   319  * user must have one or more matching permissions in order to complete the

   320  * requested operation.

   321  *

   322  * A module may deny all access to a node by setting $grants to an empty array.

   323  *

   324  * @see hook_node_grants()

   325  * @see hook_node_grants_alter()

   326  *

   327  * @param $grants

   328  *   The $grants array returned by hook_node_access_records().

   329  * @param $node

   330  *   The node for which the grants were acquired.

   331  *

   332  * The preferred use of this hook is in a module that bridges multiple node

   333  * access modules with a configurable behavior, as shown in the example with the

   334  * 'is_preview' field.

   335  *

   336  * @ingroup node_access

   337  */

   338 function hook_node_access_records_alter(&$grants, $node) {

   339   // Our module allows editors to mark specific articles with the 'is_preview'

   340   // field. If the node being saved has a TRUE value for that field, then only

   341   // our grants are retained, and other grants are removed. Doing so ensures

   342   // that our rules are enforced no matter what priority other grants are given.

   343   if ($node->is_preview) {

   344     // Our module grants are set in $grants['example'].

   345     $temp = $grants['example'];

   346     // Now remove all module grants but our own.

   347     $grants = array('example' => $temp);

   348   }

   349 }

   350 

   351 /**

   352  * Alter user access rules when trying to view, edit or delete a node.

   353  *

   354  * Node access modules establish rules for user access to content.

   355  * hook_node_grants() defines permissions for a user to view, edit or delete

   356  * nodes by building a $grants array that indicates the permissions assigned to

   357  * the user by each node access module. This hook is called to allow modules to

   358  * modify the $grants array by reference, so the interaction of multiple node

   359  * access modules can be altered or advanced business logic can be applied.

   360  *

   361  * @see hook_node_grants()

   362  *

   363  * The resulting grants are then checked against the records stored in the

   364  * {node_access} table to determine if the operation may be completed.

   365  *

   366  * A module may deny all access to a user by setting $grants to an empty array.

   367  *

   368  * @see hook_node_access_records()

   369  * @see hook_node_access_records_alter()

   370  *

   371  * @param $grants

   372  *   The $grants array returned by hook_node_grants().

   373  * @param $account

   374  *   The user account requesting access to content.

   375  * @param $op

   376  *   The operation being performed, 'view', 'update' or 'delete'.

   377  *

   378  * Developers may use this hook to either add additional grants to a user or to

   379  * remove existing grants. These rules are typically based on either the

   380  * permissions assigned to a user role, or specific attributes of a user

   381  * account.

   382  *

   383  * @ingroup node_access

   384  */

   385 function hook_node_grants_alter(&$grants, $account, $op) {

   386   // Our sample module never allows certain roles to edit or delete

   387   // content. Since some other node access modules might allow this

   388   // permission, we expressly remove it by returning an empty $grants

   389   // array for roles specified in our variable setting.

   390 

   391   // Get our list of banned roles.

   392   $restricted = variable_get('example_restricted_roles', array());

   393 

   394   if ($op != 'view' && !empty($restricted)) {

   395     // Now check the roles for this account against the restrictions.

   396     foreach ($restricted as $role_id) {

   397       if (isset($account->roles[$role_id])) {

   398         $grants = array();

   399       }

   400     }

   401   }

   402 }

   403 

   404 /**

   405  * Add mass node operations.

   406  *

   407  * This hook enables modules to inject custom operations into the mass

   408  * operations dropdown found at admin/content, by associating a callback

   409  * function with the operation, which is called when the form is submitted. The

   410  * callback function receives one initial argument, which is an array of the

   411  * checked nodes.

   412  *

   413  * @return

   414  *   An array of operations. Each operation is an associative array that may

   415  *   contain the following key-value pairs:

   416  *   - label: (required) The label for the operation, displayed in the dropdown

   417  *     menu.

   418  *   - callback: (required) The function to call for the operation.

   419  *   - callback arguments: (optional) An array of additional arguments to pass

   420  *     to the callback function.

   421  */

   422 function hook_node_operations() {

   423   $operations = array(

   424     'publish' => array(

   425       'label' => t('Publish selected content'),

   426       'callback' => 'node_mass_update',

   427       'callback arguments' => array('updates' => array('status' => NODE_PUBLISHED)),

   428     ),

   429     'unpublish' => array(

   430       'label' => t('Unpublish selected content'),

   431       'callback' => 'node_mass_update',

   432       'callback arguments' => array('updates' => array('status' => NODE_NOT_PUBLISHED)),

   433     ),

   434     'promote' => array(

   435       'label' => t('Promote selected content to front page'),

   436       'callback' => 'node_mass_update',

   437       'callback arguments' => array('updates' => array('status' => NODE_PUBLISHED, 'promote' => NODE_PROMOTED)),

   438     ),

   439     'demote' => array(

   440       'label' => t('Demote selected content from front page'),

   441       'callback' => 'node_mass_update',

   442       'callback arguments' => array('updates' => array('promote' => NODE_NOT_PROMOTED)),

   443     ),

   444     'sticky' => array(

   445       'label' => t('Make selected content sticky'),

   446       'callback' => 'node_mass_update',

   447       'callback arguments' => array('updates' => array('status' => NODE_PUBLISHED, 'sticky' => NODE_STICKY)),

   448     ),

   449     'unsticky' => array(

   450       'label' => t('Make selected content not sticky'),

   451       'callback' => 'node_mass_update',

   452       'callback arguments' => array('updates' => array('sticky' => NODE_NOT_STICKY)),

   453     ),

   454     'delete' => array(

   455       'label' => t('Delete selected content'),

   456       'callback' => NULL,

   457     ),

   458   );

   459   return $operations;

   460 }

   461 

   462 /**

   463  * Respond to node deletion.

   464  *

   465  * This hook is invoked from node_delete_multiple() after the type-specific

   466  * hook_delete() has been invoked, but before hook_entity_delete and

   467  * field_attach_delete() are called, and before the node is removed from the

   468  * node table in the database.

   469  *

   470  * @param $node

   471  *   The node that is being deleted.

   472  *

   473  * @ingroup node_api_hooks

   474  */

   475 function hook_node_delete($node) {

   476   db_delete('mytable')

   477     ->condition('nid', $node->nid)

   478     ->execute();

   479 }

   480 

   481 /**

   482  * Respond to deletion of a node revision.

   483  *

   484  * This hook is invoked from node_revision_delete() after the revision has been

   485  * removed from the node_revision table, and before

   486  * field_attach_delete_revision() is called.

   487  *

   488  * @param $node

   489  *   The node revision (node object) that is being deleted.

   490  *

   491  * @ingroup node_api_hooks

   492  */

   493 function hook_node_revision_delete($node) {

   494   db_delete('mytable')

   495     ->condition('vid', $node->vid)

   496     ->execute();

   497 }

   498 

   499 /**

   500  * Respond to creation of a new node.

   501  *

   502  * This hook is invoked from node_save() after the database query that will

   503  * insert the node into the node table is scheduled for execution, after the

   504  * type-specific hook_insert() is invoked, and after field_attach_insert() is

   505  * called.

   506  *

   507  * Note that when this hook is invoked, the changes have not yet been written to

   508  * the database, because a database transaction is still in progress. The

   509  * transaction is not finalized until the save operation is entirely completed

   510  * and node_save() goes out of scope. You should not rely on data in the

   511  * database at this time as it is not updated yet. You should also note that any

   512  * write/update database queries executed from this hook are also not committed

   513  * immediately. Check node_save() and db_transaction() for more info.

   514  *

   515  * @param $node

   516  *   The node that is being created.

   517  *

   518  * @ingroup node_api_hooks

   519  */

   520 function hook_node_insert($node) {

   521   db_insert('mytable')

   522     ->fields(array(

   523       'nid' => $node->nid,

   524       'extra' => $node->extra,

   525     ))

   526     ->execute();

   527 }

   528 

   529 /**

   530  * Act on arbitrary nodes being loaded from the database.

   531  *

   532  * This hook should be used to add information that is not in the node or node

   533  * revisions table, not to replace information that is in these tables (which

   534  * could interfere with the entity cache). For performance reasons, information

   535  * for all available nodes should be loaded in a single query where possible.

   536  *

   537  * This hook is invoked during node loading, which is handled by entity_load(),

   538  * via classes NodeController and DrupalDefaultEntityController. After the node

   539  * information is read from the database or the entity cache, hook_load() is

   540  * invoked on the node's content type module, then field_attach_load_revision()

   541  * or field_attach_load() is called, then hook_entity_load() is invoked on all

   542  * implementing modules, and finally hook_node_load() is invoked on all

   543  * implementing modules.

   544  *

   545  * @param $nodes

   546  *   An array of the nodes being loaded, keyed by nid.

   547  * @param $types

   548  *   An array containing the node types present in $nodes. Allows for an early

   549  *   return for modules that only support certain node types. However, if your

   550  *   module defines a content type, you can use hook_load() to respond to

   551  *   loading of just that content type.

   552  *

   553  * For a detailed usage example, see nodeapi_example.module.

   554  *

   555  * @ingroup node_api_hooks

   556  */

   557 function hook_node_load($nodes, $types) {

   558   // Decide whether any of $types are relevant to our purposes.

   559   if (count(array_intersect($types_we_want_to_process, $types))) {

   560     // Gather our extra data for each of these nodes.

   561     $result = db_query('SELECT nid, foo FROM {mytable} WHERE nid IN(:nids)', array(':nids' => array_keys($nodes)));

   562     // Add our extra data to the node objects.

   563     foreach ($result as $record) {

   564       $nodes[$record->nid]->foo = $record->foo;

   565     }

   566   }

   567 }

   568 

   569 /**

   570  * Control access to a node.

   571  *

   572  * Modules may implement this hook if they want to have a say in whether or not

   573  * a given user has access to perform a given operation on a node.

   574  *

   575  * The administrative account (user ID #1) always passes any access check, so

   576  * this hook is not called in that case. Users with the "bypass node access"

   577  * permission may always view and edit content through the administrative

   578  * interface.

   579  *

   580  * Note that not all modules will want to influence access on all node types. If

   581  * your module does not want to actively grant or block access, return

   582  * NODE_ACCESS_IGNORE or simply return nothing. Blindly returning FALSE will

   583  * break other node access modules.

   584  *

   585  * Also note that this function isn't called for node listings (e.g., RSS feeds,

   586  * the default home page at path 'node', a recent content block, etc.) See

   587  * @link node_access Node access rights @endlink for a full explanation.

   588  *

   589  * @param $node

   590  *   Either a node object or the machine name of the content type on which to

   591  *   perform the access check.

   592  * @param $op

   593  *   The operation to be performed. Possible values:

   594  *   - "create"

   595  *   - "delete"

   596  *   - "update"

   597  *   - "view"

   598  * @param $account

   599  *   The user object to perform the access check operation on.

   600  *

   601  * @return

   602  *   - NODE_ACCESS_ALLOW: if the operation is to be allowed.

   603  *   - NODE_ACCESS_DENY: if the operation is to be denied.

   604  *   - NODE_ACCESS_IGNORE: to not affect this operation at all.

   605  *

   606  * @ingroup node_access

   607  */

   608 function hook_node_access($node, $op, $account) {

   609   $type = is_string($node) ? $node : $node->type;

   610 

   611   if (in_array($type, node_permissions_get_configured_types())) {

   612     if ($op == 'create' && user_access('create ' . $type . ' content', $account)) {

   613       return NODE_ACCESS_ALLOW;

   614     }

   615 

   616     if ($op == 'update') {

   617       if (user_access('edit any ' . $type . ' content', $account) || (user_access('edit own ' . $type . ' content', $account) && ($account->uid == $node->uid))) {

   618         return NODE_ACCESS_ALLOW;

   619       }

   620     }

   621 

   622     if ($op == 'delete') {

   623       if (user_access('delete any ' . $type . ' content', $account) || (user_access('delete own ' . $type . ' content', $account) && ($account->uid == $node->uid))) {

   624         return NODE_ACCESS_ALLOW;

   625       }

   626     }

   627   }

   628 

   629   // Returning nothing from this function would have the same effect.

   630   return NODE_ACCESS_IGNORE;

   631 }

   632 

   633 

   634 /**

   635  * Act on a node object about to be shown on the add/edit form.

   636  *

   637  * This hook is invoked from node_object_prepare() after the type-specific

   638  * hook_prepare() is invoked.

   639  *

   640  * @param $node

   641  *   The node that is about to be shown on the add/edit form.

   642  *

   643  * @ingroup node_api_hooks

   644  */

   645 function hook_node_prepare($node) {

   646   if (!isset($node->comment)) {

   647     $node->comment = variable_get("comment_$node->type", COMMENT_NODE_OPEN);

   648   }

   649 }

   650 

   651 /**

   652  * Act on a node being displayed as a search result.

   653  *

   654  * This hook is invoked from node_search_execute(), after node_load() and

   655  * node_view() have been called.

   656  *

   657  * @param $node

   658  *   The node being displayed in a search result.

   659  *

   660  * @return array

   661  *   Extra information to be displayed with search result. This information

   662  *   should be presented as an associative array. It will be concatenated with

   663  *   the post information (last updated, author) in the default search result

   664  *   theming.

   665  *

   666  * @see template_preprocess_search_result()

   667  * @see search-result.tpl.php

   668  *

   669  * @ingroup node_api_hooks

   670  */

   671 function hook_node_search_result($node) {

   672   $comments = db_query('SELECT comment_count FROM {node_comment_statistics} WHERE nid = :nid', array('nid' => $node->nid))->fetchField();

   673   return array('comment' => format_plural($comments, '1 comment', '@count comments'));

   674 }

   675 

   676 /**

   677  * Act on a node being inserted or updated.

   678  *

   679  * This hook is invoked from node_save() before the node is saved to the

   680  * database.

   681  *

   682  * @param $node

   683  *   The node that is being inserted or updated.

   684  *

   685  * @ingroup node_api_hooks

   686  */

   687 function hook_node_presave($node) {

   688   if ($node->nid && $node->moderate) {

   689     // Reset votes when node is updated:

   690     $node->score = 0;

   691     $node->users = '';

   692     $node->votes = 0;

   693   }

   694 }

   695 

   696 /**

   697  * Respond to updates to a node.

   698  *

   699  * This hook is invoked from node_save() after the database query that will

   700  * update node in the node table is scheduled for execution, after the

   701  * type-specific hook_update() is invoked, and after field_attach_update() is

   702  * called.

   703  *

   704  * Note that when this hook is invoked, the changes have not yet been written to

   705  * the database, because a database transaction is still in progress. The

   706  * transaction is not finalized until the save operation is entirely completed

   707  * and node_save() goes out of scope. You should not rely on data in the

   708  * database at this time as it is not updated yet. You should also note that any

   709  * write/update database queries executed from this hook are also not committed

   710  * immediately. Check node_save() and db_transaction() for more info.

   711  *

   712  * @param $node

   713  *   The node that is being updated.

   714  *

   715  * @ingroup node_api_hooks

   716  */

   717 function hook_node_update($node) {

   718   db_update('mytable')

   719     ->fields(array('extra' => $node->extra))

   720     ->condition('nid', $node->nid)

   721     ->execute();

   722 }

   723 

   724 /**

   725  * Act on a node being indexed for searching.

   726  *

   727  * This hook is invoked during search indexing, after node_load(), and after the

   728  * result of node_view() is added as $node->rendered to the node object.

   729  *

   730  * @param $node

   731  *   The node being indexed.

   732  *

   733  * @return string

   734  *   Additional node information to be indexed.

   735  *

   736  * @ingroup node_api_hooks

   737  */

   738 function hook_node_update_index($node) {

   739   $text = '';

   740   $comments = db_query('SELECT subject, comment, format FROM {comment} WHERE nid = :nid AND status = :status', array(':nid' => $node->nid, ':status' => COMMENT_PUBLISHED));

   741   foreach ($comments as $comment) {

   742     $text .= '<h2>' . check_plain($comment->subject) . '</h2>' . check_markup($comment->comment, $comment->format, '', TRUE);

   743   }

   744   return $text;

   745 }

   746 

   747 /**

   748  * Perform node validation before a node is created or updated.

   749  *

   750  * This hook is invoked from node_validate(), after a user has has finished

   751  * editing the node and is previewing or submitting it. It is invoked at the

   752  * end of all the standard validation steps, and after the type-specific

   753  * hook_validate() is invoked.

   754  *

   755  * To indicate a validation error, use form_set_error().

   756  *

   757  * Note: Changes made to the $node object within your hook implementation will

   758  * have no effect.  The preferred method to change a node's content is to use

   759  * hook_node_presave() instead. If it is really necessary to change the node at

   760  * the validate stage, you can use form_set_value().

   761  *

   762  * @param $node

   763  *   The node being validated.

   764  * @param $form

   765  *   The form being used to edit the node.

   766  * @param $form_state

   767  *   The form state array.

   768  *

   769  * @ingroup node_api_hooks

   770  */

   771 function hook_node_validate($node, $form, &$form_state) {

   772   if (isset($node->end) && isset($node->start)) {

   773     if ($node->start > $node->end) {

   774       form_set_error('time', t('An event may not end before it starts.'));

   775     }

   776   }

   777 }

   778 

   779 /**

   780  * Act on a node after validated form values have been copied to it.

   781  *

   782  * This hook is invoked when a node form is submitted with either the "Save" or

   783  * "Preview" button, after form values have been copied to the form state's node

   784  * object, but before the node is saved or previewed. It is a chance for modules

   785  * to adjust the node's properties from what they are simply after a copy from

   786  * $form_state['values']. This hook is intended for adjusting non-field-related

   787  * properties. See hook_field_attach_submit() for customizing field-related

   788  * properties.

   789  *

   790  * @param $node

   791  *   The node object being updated in response to a form submission.

   792  * @param $form

   793  *   The form being used to edit the node.

   794  * @param $form_state

   795  *   The form state array.

   796  *

   797  * @ingroup node_api_hooks

   798  */

   799 function hook_node_submit($node, $form, &$form_state) {

   800   // Decompose the selected menu parent option into 'menu_name' and 'plid', if

   801   // the form used the default parent selection widget.

   802   if (!empty($form_state['values']['menu']['parent'])) {

   803     list($node->menu['menu_name'], $node->menu['plid']) = explode(':', $form_state['values']['menu']['parent']);

   804   }

   805 }

   806 

   807 /**

   808  * Act on a node that is being assembled before rendering.

   809  *

   810  * The module may add elements to $node->content prior to rendering. This hook

   811  * will be called after hook_view(). The structure of $node->content is a

   812  * renderable array as expected by drupal_render().

   813  *

   814  * When $view_mode is 'rss', modules can also add extra RSS elements and

   815  * namespaces to $node->rss_elements and $node->rss_namespaces respectively for

   816  * the RSS item generated for this node.

   817  * For details on how this is used, see node_feed().

   818  *

   819  * @see blog_node_view()

   820  * @see forum_node_view()

   821  * @see comment_node_view()

   822  *

   823  * @param $node

   824  *   The node that is being assembled for rendering.

   825  * @param $view_mode

   826  *   The $view_mode parameter from node_view().

   827  * @param $langcode

   828  *   The language code used for rendering.

   829  *

   830  * @see hook_entity_view()

   831  *

   832  * @ingroup node_api_hooks

   833  */

   834 function hook_node_view($node, $view_mode, $langcode) {

   835   $node->content['my_additional_field'] = array(

   836     '#markup' => $additional_field,

   837     '#weight' => 10,

   838     '#theme' => 'mymodule_my_additional_field',

   839   );

   840 }

   841 

   842 /**

   843  * Alter the results of node_view().

   844  *

   845  * This hook is called after the content has been assembled in a structured

   846  * array and may be used for doing processing which requires that the complete

   847  * node content structure has been built.

   848  *

   849  * If the module wishes to act on the rendered HTML of the node rather than the

   850  * structured content array, it may use this hook to add a #post_render

   851  * callback.  Alternatively, it could also implement hook_preprocess_node(). See

   852  * drupal_render() and theme() documentation respectively for details.

   853  *

   854  * @param $build

   855  *   A renderable array representing the node content.

   856  *

   857  * @see node_view()

   858  * @see hook_entity_view_alter()

   859  *

   860  * @ingroup node_api_hooks

   861  */

   862 function hook_node_view_alter(&$build) {

   863   if ($build['#view_mode'] == 'full' && isset($build['an_additional_field'])) {

   864     // Change its weight.

   865     $build['an_additional_field']['#weight'] = -10;

   866   }

   867 

   868   // Add a #post_render callback to act on the rendered HTML of the node.

   869   $build['#post_render'][] = 'my_module_node_post_render';

   870 }

   871 

   872 /**

   873  * Define module-provided node types.

   874  *

   875  * This hook allows a module to define one or more of its own node types. For

   876  * example, the blog module uses it to define a blog node-type named "Blog

   877  * entry." The name and attributes of each desired node type are specified in an

   878  * array returned by the hook.

   879  *

   880  * Only module-provided node types should be defined through this hook. User-

   881  * provided (or 'custom') node types should be defined only in the 'node_type'

   882  * database table, and should be maintained by using the node_type_save() and

   883  * node_type_delete() functions.

   884  *

   885  * @return

   886  *   An array of information defining the module's node types. The array

   887  *   contains a sub-array for each node type, with the machine-readable type

   888  *   name as the key. Each sub-array has up to 10 attributes. Possible

   889  *   attributes:

   890  *   - name: (required) The human-readable name of the node type.

   891  *   - base: (required) The base name for implementations of node-type-specific

   892  *     hooks that respond to this node type. Base is usually the name of the

   893  *     module or 'node_content', but not always. See

   894  *     @link node_api_hooks Node API hooks @endlink for more information.

   895  *   - description: (required) A brief description of the node type.

   896  *   - help: (optional) Help information shown to the user when creating a node

   897  *     of this type.

   898  *   - has_title: (optional) A Boolean indicating whether or not this node type

   899  *     has a title field.

   900  *   - title_label: (optional) The label for the title field of this content

   901  *     type.

   902  *   - locked: (optional) A Boolean indicating whether the administrator can

   903  *     change the machine name of this type. FALSE = changeable (not locked),

   904  *     TRUE = unchangeable (locked).

   905  *

   906  * The machine name of a node type should contain only letters, numbers, and

   907  * underscores. Underscores will be converted into hyphens for the purpose of

   908  * constructing URLs.

   909  *

   910  * All attributes of a node type that are defined through this hook (except for

   911  * 'locked') can be edited by a site administrator. This includes the

   912  * machine-readable name of a node type, if 'locked' is set to FALSE.

   913  *

   914  * @ingroup node_api_hooks

   915  */

   916 function hook_node_info() {

   917   return array(

   918     'blog' => array(

   919       'name' => t('Blog entry'),

   920       'base' => 'blog',

   921       'description' => t('Use for multi-user blogs. Every user gets a personal blog.'),

   922     )

   923   );

   924 }

   925 

   926 /**

   927  * Provide additional methods of scoring for core search results for nodes.

   928  *

   929  * A node's search score is used to rank it among other nodes matched by the

   930  * search, with the highest-ranked nodes appearing first in the search listing.

   931  *

   932  * For example, a module allowing users to vote on content could expose an

   933  * option to allow search results' rankings to be influenced by the average

   934  * voting score of a node.

   935  *

   936  * All scoring mechanisms are provided as options to site administrators, and

   937  * may be tweaked based on individual sites or disabled altogether if they do

   938  * not make sense. Individual scoring mechanisms, if enabled, are assigned a

   939  * weight from 1 to 10. The weight represents the factor of magnification of

   940  * the ranking mechanism, with higher-weighted ranking mechanisms having more

   941  * influence. In order for the weight system to work, each scoring mechanism

   942  * must return a value between 0 and 1 for every node. That value is then

   943  * multiplied by the administrator-assigned weight for the ranking mechanism,

   944  * and then the weighted scores from all ranking mechanisms are added, which

   945  * brings about the same result as a weighted average.

   946  *

   947  * @return

   948  *   An associative array of ranking data. The keys should be strings,

   949  *   corresponding to the internal name of the ranking mechanism, such as

   950  *   'recent', or 'comments'. The values should be arrays themselves, with the

   951  *   following keys available:

   952  *   - title: (required) The human readable name of the ranking mechanism.

   953  *   - join: (optional) An array with information to join any additional

   954  *     necessary table. This is not necessary if the table required is already

   955  *     joined to by the base query, such as for the {node} table. Other tables

   956  *     should use the full table name as an alias to avoid naming collisions.

   957  *   - score: (required) The part of a query string to calculate the score for

   958  *     the ranking mechanism based on values in the database. This does not need

   959  *     to be wrapped in parentheses, as it will be done automatically; it also

   960  *     does not need to take the weighted system into account, as it will be

   961  *     done automatically. It does, however, need to calculate a decimal between

   962  *     0 and 1; be careful not to cast the entire score to an integer by

   963  *     inadvertently introducing a variable argument.

   964  *   - arguments: (optional) If any arguments are required for the score, they

   965  *     can be specified in an array here.

   966  *

   967  * @ingroup node_api_hooks

   968  */

   969 function hook_ranking() {

   970   // If voting is disabled, we can avoid returning the array, no hard feelings.

   971   if (variable_get('vote_node_enabled', TRUE)) {

   972     return array(

   973       'vote_average' => array(

   974         'title' => t('Average vote'),

   975         // Note that we use i.sid, the search index's search item id, rather than

   976         // n.nid.

   977         'join' => array(

   978           'type' => 'LEFT',

   979           'table' => 'vote_node_data',

   980           'alias' => 'vote_node_data',

   981           'on' => 'vote_node_data.nid = i.sid',

   982         ),

   983         // The highest possible score should be 1, and the lowest possible score,

   984         // always 0, should be 0.

   985         'score' => 'vote_node_data.average / CAST(%f AS DECIMAL)',

   986         // Pass in the highest possible voting score as a decimal argument.

   987         'arguments' => array(variable_get('vote_score_max', 5)),

   988       ),

   989     );

   990   }

   991 }

   992 

   993 

   994 /**

   995  * Respond to node type creation.

   996  *

   997  * This hook is invoked from node_type_save() after the node type is added to

   998  * the database.

   999  *

  1000  * @param $info

  1001  *   The node type object that is being created.

  1002  */

  1003 function hook_node_type_insert($info) {

  1004   drupal_set_message(t('You have just created a content type with a machine name %type.', array('%type' => $info->type)));

  1005 }

  1006 

  1007 /**

  1008  * Respond to node type updates.

  1009  *

  1010  * This hook is invoked from node_type_save() after the node type is updated in

  1011  * the database.

  1012  *

  1013  * @param $info

  1014  *   The node type object that is being updated.

  1015  */

  1016 function hook_node_type_update($info) {

  1017   if (!empty($info->old_type) && $info->old_type != $info->type) {

  1018     $setting = variable_get('comment_' . $info->old_type, COMMENT_NODE_OPEN);

  1019     variable_del('comment_' . $info->old_type);

  1020     variable_set('comment_' . $info->type, $setting);

  1021   }

  1022 }

  1023 

  1024 /**

  1025  * Respond to node type deletion.

  1026  *

  1027  * This hook is invoked from node_type_delete() after the node type is removed

  1028  * from the database.

  1029  *

  1030  * @param $info

  1031  *   The node type object that is being deleted.

  1032  */

  1033 function hook_node_type_delete($info) {

  1034   variable_del('comment_' . $info->type);

  1035 }

  1036 

  1037 /**

  1038  * Respond to node deletion.

  1039  *

  1040  * This is a node-type-specific hook, which is invoked only for the node type

  1041  * being affected. See

  1042  * @link node_api_hooks Node API hooks @endlink for more information.

  1043  *

  1044  * Use hook_node_delete() to respond to node deletion of all node types.

  1045  *

  1046  * This hook is invoked from node_delete_multiple() before hook_node_delete()

  1047  * is invoked and before field_attach_delete() is called.

  1048  *

  1049  * Note that when this hook is invoked, the changes have not yet been written

  1050  * to the database, because a database transaction is still in progress. The

  1051  * transaction is not finalized until the delete operation is entirely

  1052  * completed and node_delete_multiple() goes out of scope. You should not rely

  1053  * on data in the database at this time as it is not updated yet. You should

  1054  * also note that any write/update database queries executed from this hook are

  1055  * also not committed immediately. Check node_delete_multiple() and

  1056  * db_transaction() for more info.

  1057  *

  1058  * @param $node

  1059  *   The node that is being deleted.

  1060  *

  1061  * @ingroup node_api_hooks

  1062  */

  1063 function hook_delete($node) {

  1064   db_delete('mytable')

  1065     ->condition('nid', $node->nid)

  1066     ->execute();

  1067 }

  1068 

  1069 /**

  1070  * Act on a node object about to be shown on the add/edit form.

  1071  *

  1072  * This is a node-type-specific hook, which is invoked only for the node type

  1073  * being affected. See

  1074  * @link node_api_hooks Node API hooks @endlink for more information.

  1075  *

  1076  * Use hook_node_prepare() to respond to node preparation of all node types.

  1077  *

  1078  * This hook is invoked from node_object_prepare() before the general

  1079  * hook_node_prepare() is invoked.

  1080  *

  1081  * @param $node

  1082  *   The node that is about to be shown on the add/edit form.

  1083  *

  1084  * @ingroup node_api_hooks

  1085  */

  1086 function hook_prepare($node) {

  1087   if (!isset($node->mymodule_value)) {

  1088     $node->mymodule_value = 'foo';

  1089   }

  1090 }

  1091 

  1092 /**

  1093  * Display a node editing form.

  1094  *

  1095  * This is a node-type-specific hook, which is invoked only for the node type

  1096  * being affected. See

  1097  * @link node_api_hooks Node API hooks @endlink for more information.

  1098  *

  1099  * Use hook_form_BASE_FORM_ID_alter(), with base form ID 'node_form', to alter

  1100  * node forms for all node types.

  1101  *

  1102  * This hook, implemented by node modules, is called to retrieve the form

  1103  * that is displayed to create or edit a node. This form is displayed at path

  1104  * node/add/[node type] or node/[node ID]/edit.

  1105  *

  1106  * The submit and preview buttons, administrative and display controls, and

  1107  * sections added by other modules (such as path settings, menu settings,

  1108  * comment settings, and fields managed by the Field UI module) are

  1109  * displayed automatically by the node module. This hook just needs to

  1110  * return the node title and form editing fields specific to the node type.

  1111  *

  1112  * @param $node

  1113  *   The node being added or edited.

  1114  * @param $form_state

  1115  *   The form state array.

  1116  *

  1117  * @return

  1118  *   An array containing the title and any custom form elements to be displayed

  1119  *   in the node editing form.

  1120  *

  1121  * @ingroup node_api_hooks

  1122  */

  1123 function hook_form($node, &$form_state) {

  1124   $type = node_type_get_type($node);

  1125 

  1126   $form['title'] = array(

  1127     '#type' => 'textfield',

  1128     '#title' => check_plain($type->title_label),

  1129     '#default_value' => !empty($node->title) ? $node->title : '',

  1130     '#required' => TRUE, '#weight' => -5

  1131   );

  1132 

  1133   $form['field1'] = array(

  1134     '#type' => 'textfield',

  1135     '#title' => t('Custom field'),

  1136     '#default_value' => $node->field1,