Club Drupal

<?php

/**

 * @file

 * Hooks provided by Drupal core and the System module.

 */

/**

 * @addtogroup hooks

 * @{

 */

/**

 * Defines one or more hooks that are exposed by a module.

 *

 * Normally hooks do not need to be explicitly defined. However, by declaring a

 * hook explicitly, a module may define a "group" for it. Modules that implement

 * a hook may then place their implementation in either $module.module or in

 * $module.$group.inc. If the hook is located in $module.$group.inc, then that

 * file will be automatically loaded when needed.

 * In general, hooks that are rarely invoked and/or are very large should be

 * placed in a separate include file, while hooks that are very short or very

 * frequently called should be left in the main module file so that they are

 * always available.

 *

 * @return

 *   An associative array whose keys are hook names and whose values are an

 *   associative array containing:

 *   - group: A string defining the group to which the hook belongs. The module

 *     system will determine whether a file with the name $module.$group.inc

 *     exists, and automatically load it when required.

 *

 * See system_hook_info() for all hook groups defined by Drupal core.

 *

 * @see hook_hook_info_alter().

 */

function hook_hook_info() {

  $hooks['token_info'] = array(

    'group' => 'tokens',

  );

  $hooks['tokens'] = array(

    'group' => 'tokens',

  );

  return $hooks;

}

/**

 * Alter information from hook_hook_info().

 *

 * @param $hooks

 *   Information gathered by module_hook_info() from other modules'

 *   implementations of hook_hook_info(). Alter this array directly.

 *   See hook_hook_info() for information on what this may contain.

 */

function hook_hook_info_alter(&$hooks) {

  // Our module wants to completely override the core tokens, so make

  // sure the core token hooks are not found.

  $hooks['token_info']['group'] = 'mytokens';

  $hooks['tokens']['group'] = 'mytokens';

}

/**

 * Inform the base system and the Field API about one or more entity types.

 *

 * Inform the system about one or more entity types (i.e., object types that

 * can be loaded via entity_load() and, optionally, to which fields can be

 * attached).

 *

 * @return

 *   An array whose keys are entity type names and whose values identify

 *   properties of those types that the system needs to know about:

 *   - label: The human-readable name of the type.

 *   - controller class: The name of the class that is used to load the objects.

 *     The class has to implement the DrupalEntityControllerInterface interface.

 *     Leave blank to use the DrupalDefaultEntityController implementation.

 *   - base table: (used by DrupalDefaultEntityController) The name of the

 *     entity type's base table.

 *   - revision table: The name of the entity type's revision table (if any).

 *   - static cache: (used by DrupalDefaultEntityController) FALSE to disable

 *     static caching of entities during a page request. Defaults to TRUE.

 *   - field cache: (used by Field API loading and saving of field data) FALSE

 *     to disable Field API's persistent cache of field data. Only recommended

 *     if a higher level persistent cache is available for the entity type.

 *     Defaults to TRUE.

 *   - load hook: The name of the hook which should be invoked by

 *     DrupalDefaultEntityController:attachLoad(), for example 'node_load'.

 *   - uri callback: The name of an implementation of

 *     callback_entity_info_uri().

 *   - label callback: (optional) The name of an implementation of

 *     callback_entity_info_label(), which returns the label of the entity. The

 *     entity label is the main string associated with an entity; for example,

 *     the title of a node or the subject of a comment. If there is an entity

 *     object property that defines the label, then using the 'label' element of

 *     the 'entity keys' return value component suffices to provide this

 *     information (see below). Alternatively, specifying this callback allows

 *     more complex logic to determine the label of an entity. See also the

 *     entity_label() function, which implements this logic.

 *   - language callback: (optional) The name of an implementation of

 *     callback_entity_info_language(). In most situations, when needing to

 *     determine this value, inspecting a property named after the 'language'

 *     element of the 'entity keys' should be enough. The language callback is

 *     meant to be used primarily for temporary alterations of the property

 *     value: entity-defining modules are encouraged to always define a

 *     language property, instead of using the callback as main entity language

 *     source. In fact not having a language property defined is likely to

 *     prevent an entity from being queried by language. Moreover, given that

 *     entity_language() is not necessarily used everywhere it would be

 *     appropriate, modules implementing the language callback should be aware

 *     that this might not be always called.

 *   - fieldable: Set to TRUE if you want your entity type to accept fields

 *     being attached to it.

 *   - translation: An associative array of modules registered as field

 *     translation handlers. Array keys are the module names, array values

 *     can be any data structure the module uses to provide field translation.

 *     Any empty value disallows the module to appear as a translation handler.

 *   - entity keys: An array describing how the Field API can extract the

 *     information it needs from the objects of the type. Elements:

 *     - id: The name of the property that contains the primary id of the

 *       entity. Every entity object passed to the Field API must have this

 *       property and its value must be numeric.

 *     - revision: The name of the property that contains the revision id of

 *       the entity. The Field API assumes that all revision ids are unique

 *       across all entities of a type. This entry can be omitted if the

 *       entities of this type are not versionable.

 *     - bundle: The name of the property that contains the bundle name for the

 *       entity. The bundle name defines which set of fields are attached to

 *       the entity (e.g. what nodes call "content type"). This entry can be

 *       omitted if this entity type exposes a single bundle (all entities have

 *       the same collection of fields). The name of this single bundle will be

 *       the same as the entity type.

 *     - label: The name of the property that contains the entity label. For

 *       example, if the entity's label is located in $entity->subject, then

 *       'subject' should be specified here. If complex logic is required to

 *       build the label, a 'label callback' should be defined instead (see

 *       the 'label callback' section above for details).

 *     - language: The name of the property, typically 'language', that contains

 *       the language code representing the language the entity has been created

 *       in. This value may be changed when editing the entity and represents

 *       the language its textual components are supposed to have. If no

 *       language property is available, the 'language callback' may be used

 *       instead. This entry can be omitted if the entities of this type are not

 *       language-aware.

 *   - bundle keys: An array describing how the Field API can extract the

 *     information it needs from the bundle objects for this type. This entry

 *     is required if the 'path' provided in the 'bundles'/'admin' section

 *     identifies the bundle using a named menu placeholder whose loader

 *     callback returns an object (e.g., $vocabulary for taxonomy terms, or

 *     $node_type for nodes). If the path does not include the bundle, or the

 *     bundle is just a string rather than an automatically loaded object, then

 *     this can be omitted. Elements:

 *     - bundle: The name of the property of the bundle object that contains

 *       the name of the bundle object.

 *   - bundles: An array describing all bundles for this object type. Keys are

 *     bundles machine names, as found in the objects' 'bundle' property

 *     (defined in the 'entity keys' entry above). This entry can be omitted if

 *     this entity type exposes a single bundle (all entities have the same

 *     collection of fields). The name of this single bundle will be the same as

 *     the entity type. Elements:

 *     - label: The human-readable name of the bundle.

 *     - uri callback: Same as the 'uri callback' key documented above for the

 *       entity type, but for the bundle only. When determining the URI of an

 *       entity, if a 'uri callback' is defined for both the entity type and

 *       the bundle, the one for the bundle is used.

 *     - admin: An array of information that allows Field UI pages to attach

 *       themselves to the existing administration pages for the bundle.

 *       Elements:

 *       - path: the path of the bundle's main administration page, as defined

 *         in hook_menu(). If the path includes a placeholder for the bundle,

 *         the 'bundle argument' and 'real path' keys below are required.

 *       - bundle argument: The position of the bundle placeholder in 'path', if

 *         any.

 *       - real path: The actual path (no placeholder) of the bundle's main

 *         administration page. This will be used to generate links.

 *       - access callback: As in hook_menu(). 'user_access' will be assumed if

 *         no value is provided.

 *       - access arguments: As in hook_menu().

 *   - view modes: An array describing the view modes for the entity type. View

 *     modes let entities be displayed differently depending on the context.

 *     For instance, a node can be displayed differently on its own page

 *     ('full' mode), on the home page or taxonomy listings ('teaser' mode), or

 *     in an RSS feed ('rss' mode). Modules taking part in the display of the

 *     entity (notably the Field API) can adjust their behavior depending on

 *     the requested view mode. An additional 'default' view mode is available

 *     for all entity types. This view mode is not intended for actual entity

 *     display, but holds default display settings. For each available view

 *     mode, administrators can configure whether it should use its own set of

 *     field display settings, or just replicate the settings of the 'default'

 *     view mode, thus reducing the amount of display configurations to keep

 *     track of. Keys of the array are view mode names. Each view mode is

 *     described by an array with the following key/value pairs:

 *     - label: The human-readable name of the view mode

 *     - custom settings: A boolean specifying whether the view mode should by

 *       default use its own custom field display settings. If FALSE, entities

 *       displayed in this view mode will reuse the 'default' display settings

 *       by default (e.g. right after the module exposing the view mode is

 *       enabled), but administrators can later use the Field UI to apply custom

 *       display settings specific to the view mode.

 *

 * @see entity_load()

 * @see hook_entity_info_alter()

 */

function hook_entity_info() {

  $return = array(

    'node' => array(

      'label' => t('Node'),

      'controller class' => 'NodeController',

      'base table' => 'node',

      'revision table' => 'node_revision',

      'uri callback' => 'node_uri',

      'fieldable' => TRUE,

      'translation' => array(

        'locale' => TRUE,

      ),

      'entity keys' => array(

        'id' => 'nid',

        'revision' => 'vid',

        'bundle' => 'type',

        'language' => 'language',

      ),

      'bundle keys' => array(

        'bundle' => 'type',

      ),

      'bundles' => array(),

      'view modes' => array(

        'full' => array(

          'label' => t('Full content'),

          'custom settings' => FALSE,

        ),

        'teaser' => array(

          'label' => t('Teaser'),

          'custom settings' => TRUE,

        ),

        'rss' => array(

          'label' => t('RSS'),

          'custom settings' => FALSE,

        ),

      ),

    ),

  );

  // Search integration is provided by node.module, so search-related

  // view modes for nodes are defined here and not in search.module.

  if (module_exists('search')) {

    $return['node']['view modes'] += array(

      'search_index' => array(

        'label' => t('Search index'),

        'custom settings' => FALSE,

      ),

      'search_result' => array(

        'label' => t('Search result highlighting input'),

        'custom settings' => FALSE,

      ),

    );

  }

  // Bundles must provide a human readable name so we can create help and error

  // messages, and the path to attach Field admin pages to.

  foreach (node_type_get_names() as $type => $name) {

    $return['node']['bundles'][$type] = array(

      'label' => $name,

      'admin' => array(

        'path' => 'admin/structure/types/manage/%node_type',

        'real path' => 'admin/structure/types/manage/' . str_replace('_', '-', $type),

        'bundle argument' => 4,

        'access arguments' => array('administer content types'),

      ),

    );

  }

  return $return;

}

/**

 * Alter the entity info.

 *

 * Modules may implement this hook to alter the information that defines an

 * entity. All properties that are available in hook_entity_info() can be

 * altered here.

 *

 * @param $entity_info

 *   The entity info array, keyed by entity name.

 *

 * @see hook_entity_info()

 */

function hook_entity_info_alter(&$entity_info) {

  // Set the controller class for nodes to an alternate implementation of the

  // DrupalEntityController interface.

  $entity_info['node']['controller class'] = 'MyCustomNodeController';

}

/**

 * Act on entities when loaded.

 *

 * This is a generic load hook called for all entity types loaded via the

 * entity API.

 *

 * @param $entities

 *   The entities keyed by entity ID.

 * @param $type

 *   The type of entities being loaded (i.e. node, user, comment).

 */

function hook_entity_load($entities, $type) {

  foreach ($entities as $entity) {

    $entity->foo = mymodule_add_something($entity, $type);

  }

}

/**

 * Act on an entity before it is about to be created or updated.

 *

 * @param $entity

 *   The entity object.

 * @param $type

 *   The type of entity being saved (i.e. node, user, comment).

 */

function hook_entity_presave($entity, $type) {

  $entity->changed = REQUEST_TIME;

}

/**

 * Act on entities when inserted.

 *

 * @param $entity

 *   The entity object.

 * @param $type

 *   The type of entity being inserted (i.e. node, user, comment).

 */

function hook_entity_insert($entity, $type) {

  // Insert the new entity into a fictional table of all entities.

  $info = entity_get_info($type);

  list($id) = entity_extract_ids($type, $entity);

  db_insert('example_entity')

    ->fields(array(

      'type' => $type,

      'id' => $id,

      'created' => REQUEST_TIME,

      'updated' => REQUEST_TIME,

    ))

    ->execute();

}

/**

 * Act on entities when updated.

 *

 * @param $entity

 *   The entity object.

 * @param $type

 *   The type of entity being updated (i.e. node, user, comment).

 */

function hook_entity_update($entity, $type) {

  // Update the entity's entry in a fictional table of all entities.

  $info = entity_get_info($type);

  list($id) = entity_extract_ids($type, $entity);

  db_update('example_entity')

    ->fields(array(

      'updated' => REQUEST_TIME,

    ))

    ->condition('type', $type)

    ->condition('id', $id)

    ->execute();

}

/**

 * Act on entities when deleted.

 *

 * @param $entity

 *   The entity object.

 * @param $type

 *   The type of entity being deleted (i.e. node, user, comment).

 */

function hook_entity_delete($entity, $type) {

  // Delete the entity's entry from a fictional table of all entities.

  $info = entity_get_info($type);

  list($id) = entity_extract_ids($type, $entity);

  db_delete('example_entity')

    ->condition('type', $type)

    ->condition('id', $id)

    ->execute();

}

/**

 * Alter or execute an EntityFieldQuery.

 *

 * @param EntityFieldQuery $query

 *   An EntityFieldQuery. One of the most important properties to be changed is

 *   EntityFieldQuery::executeCallback. If this is set to an existing function,

 *   this function will get the query as its single argument and its result

 *   will be the returned as the result of EntityFieldQuery::execute(). This can

 *   be used to change the behavior of EntityFieldQuery entirely. For example,

 *   the default implementation can only deal with one field storage engine, but

 *   it is possible to write a module that can query across field storage

 *   engines. Also, the default implementation presumes entities are stored in

 *   SQL, but the execute callback could instead query any other entity storage,

 *   local or remote.

 *

 *   Note the $query->altered attribute which is TRUE in case the query has

 *   already been altered once. This happens with cloned queries.

 *   If there is a pager, then such a cloned query will be executed to count

 *   all elements. This query can be detected by checking for

 *   ($query->pager && $query->count), allowing the driver to return 0 from

 *   the count query and disable the pager.

 */

function hook_entity_query_alter($query) {

  $query->executeCallback = 'my_module_query_callback';

}

/**

 * Act on entities being assembled before rendering.

 *

 * @param $entity

 *   The entity object.

 * @param $type

 *   The type of entity being rendered (i.e. node, user, comment).

 * @param $view_mode

 *   The view mode the entity is rendered in.

 * @param $langcode

 *   The language code used for rendering.

 *

 * The module may add elements to $entity->content prior to rendering. The

 * structure of $entity->content is a renderable array as expected by

 * drupal_render().

 *

 * @see hook_entity_view_alter()

 * @see hook_comment_view()

 * @see hook_node_view()

 * @see hook_user_view()

 */

function hook_entity_view($entity, $type, $view_mode, $langcode) {

  $entity->content['my_additional_field'] = array(

    '#markup' => $additional_field,

    '#weight' => 10,

    '#theme' => 'mymodule_my_additional_field',

  );

}

/**

 * Alter the results of ENTITY_view().

 *

 * 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

 * entity content structure has been built.

 *

 * If a module wishes to act on the rendered HTML of the entity rather than the

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

 * callback. Alternatively, it could also implement hook_preprocess_ENTITY().

 * See drupal_render() and theme() for details.

 *

 * @param $build

 *   A renderable array representing the entity content.

 * @param $type

 *   The type of entity being rendered (i.e. node, user, comment).

 *

 * @see hook_entity_view()

 * @see hook_comment_view_alter()

 * @see hook_node_view_alter()

 * @see hook_taxonomy_term_view_alter()

 * @see hook_user_view_alter()

 */

function hook_entity_view_alter(&$build, $type) {

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

    // Change its weight.

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

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

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

  }

}

/**

 * Change the view mode of an entity that is being displayed.

 *

 * @param string $view_mode

 *   The view_mode that is to be used to display the entity.

 * @param array $context

 *   Array with contextual information, including:

 *   - entity_type: The type of the entity that is being viewed.

 *   - entity: The entity object.

 *   - langcode: The langcode the entity is being viewed in.

 */

function hook_entity_view_mode_alter(&$view_mode, $context) {

  // For nodes, change the view mode when it is teaser.

  if ($context['entity_type'] == 'node' && $view_mode == 'teaser') {

    $view_mode = 'my_custom_view_mode';

  }

}

/**

 * Define administrative paths.

 *

 * Modules may specify whether or not the paths they define in hook_menu() are

 * to be considered administrative. Other modules may use this information to

 * display those pages differently (e.g. in a modal overlay, or in a different

 * theme).

 *

 * To change the administrative status of menu items defined in another module's

 * hook_menu(), modules should implement hook_admin_paths_alter().

 *

 * @return

 *   An associative array. For each item, the key is the path in question, in

 *   a format acceptable to drupal_match_path(). The value for each item should

 *   be TRUE (for paths considered administrative) or FALSE (for non-

 *   administrative paths).

 *

 * @see hook_menu()

 * @see drupal_match_path()

 * @see hook_admin_paths_alter()

 */

function hook_admin_paths() {

  $paths = array(

    'mymodule/*/add' => TRUE,

    'mymodule/*/edit' => TRUE,

  );

  return $paths;

}

/**

 * Redefine administrative paths defined by other modules.

 *

 * @param $paths

 *   An associative array of administrative paths, as defined by implementations

 *   of hook_admin_paths().

 *

 * @see hook_admin_paths()

 */

function hook_admin_paths_alter(&$paths) {

  // Treat all user pages as administrative.

  $paths['user'] = TRUE;

  $paths['user/*'] = TRUE;

  // Treat the forum topic node form as a non-administrative page.

  $paths['node/add/forum'] = FALSE;

}

/**

 * Act on entities as they are being prepared for view.

 *

 * Allows you to operate on multiple entities as they are being prepared for

 * view. Only use this if attaching the data during the entity_load() phase

 * is not appropriate, for example when attaching other 'entity' style objects.

 *

 * @param $entities

 *   The entities keyed by entity ID.

 * @param $type

 *   The type of entities being loaded (i.e. node, user, comment).

 * @param $langcode

 *   The language to display the entity in.

 */

function hook_entity_prepare_view($entities, $type, $langcode) {

  // Load a specific node into the user object for later theming.

  if ($type == 'user') {

    $nodes = mymodule_get_user_nodes(array_keys($entities));

    foreach ($entities as $uid => $entity) {

      $entity->user_node = $nodes[$uid];

    }

  }

}

/**

 * Perform periodic actions.

 *

 * Modules that require some commands to be executed periodically can

 * implement hook_cron(). The engine will then call the hook whenever a cron

 * run happens, as defined by the administrator. Typical tasks managed by

 * hook_cron() are database maintenance, backups, recalculation of settings

 * or parameters, automated mailing, and retrieving remote data.

 *

 * Short-running or non-resource-intensive tasks can be executed directly in

 * the hook_cron() implementation.

 *

 * Long-running tasks and tasks that could time out, such as retrieving remote

 * data, sending email, and intensive file tasks, should use the queue API

 * instead of executing the tasks directly. To do this, first define one or

 * more queues via hook_cron_queue_info(). Then, add items that need to be

 * processed to the defined queues.

 */

function hook_cron() {

  // Short-running operation example, not using a queue:

  // Delete all expired records since the last cron run.

  $expires = variable_get('mymodule_cron_last_run', REQUEST_TIME);

  db_delete('mymodule_table')

    ->condition('expires', $expires, '>=')

    ->execute();

  variable_set('mymodule_cron_last_run', REQUEST_TIME);

  // Long-running operation example, leveraging a queue:

  // Fetch feeds from other sites.

  $result = db_query('SELECT * FROM {aggregator_feed} WHERE checked + refresh < :time AND refresh <> :never', array(

    ':time' => REQUEST_TIME,

    ':never' => AGGREGATOR_CLEAR_NEVER,

  ));

  $queue = DrupalQueue::get('aggregator_feeds');

  foreach ($result as $feed) {

    $queue->createItem($feed);

  }

}

/**

 * Declare queues holding items that need to be run periodically.

 *

 * While there can be only one hook_cron() process running at the same time,

 * there can be any number of processes defined here running. Because of

 * this, long running tasks are much better suited for this API. Items queued

 * in hook_cron() might be processed in the same cron run if there are not many

 * items in the queue, otherwise it might take several requests, which can be

 * run in parallel.

 *

 * @return

 *   An associative array where the key is the queue name and the value is

 *   again an associative array. Possible keys are:

 *   - 'worker callback': The name of the function to call. It will be called

 *     with one argument, the item created via DrupalQueue::createItem().

 *   - 'time': (optional) How much time Drupal should spend on calling this

 *     worker in seconds. Defaults to 15.

 *   - 'skip on cron': (optional) Set to TRUE to avoid being processed during

 *     cron runs (for example, if you want to control all queue execution

 *     manually).

 *

 * @see hook_cron()

 * @see hook_cron_queue_info_alter()

 */

function hook_cron_queue_info() {

  $queues['aggregator_feeds'] = array(

    'worker callback' => 'aggregator_refresh',

    'time' => 60,

  );

  return $queues;

}

/**

 * Alter cron queue information before cron runs.

 *

 * Called by drupal_cron_run() to allow modules to alter cron queue settings

 * before any jobs are processesed.

 *

 * @param array $queues

 *   An array of cron queue information.

 *

 * @see hook_cron_queue_info()

 * @see drupal_cron_run()

 */

function hook_cron_queue_info_alter(&$queues) {

  // This site has many feeds so let's spend 90 seconds on each cron run

  // updating feeds instead of the default 60.

  $queues['aggregator_feeds']['time'] = 90;

}

/**

 * Allows modules to declare their own Form API element types and specify their

 * default values.

 *

 * This hook allows modules to declare their own form element types and to

 * specify their default values. The values returned by this hook will be

 * merged with the elements returned by hook_form() implementations and so

 * can return defaults for any Form APIs keys in addition to those explicitly

 * mentioned below.

 *

 * Each of the form element types defined by this hook is assumed to have

 * a matching theme function, e.g. theme_elementtype(), which should be

 * registered with hook_theme() as normal.

 *

 * For more information about custom element types see the explanation at

 * http://drupal.org/node/169815.

 *

 * @return

 *  An associative array describing the element types being defined. The array

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

 *  name as the key. Each sub-array has a number of possible attributes:

 *  - "#input": boolean indicating whether or not this element carries a value

 *    (even if it's hidden).

 *  - "#process": array of callback functions taking $element, $form_state,

 *    and $complete_form.

 *  - "#after_build": array of callback functions taking $element and $form_state.

 *  - "#validate": array of callback functions taking $form and $form_state.

 *  - "#element_validate": array of callback functions taking $element and

 *    $form_state.

 *  - "#pre_render": array of callback functions taking $element and $form_state.

 *  - "#post_render": array of callback functions taking $element and $form_state.

 *  - "#submit": array of callback functions taking $form and $form_state.

 *  - "#title_display": optional string indicating if and how #title should be

 *    displayed, see theme_form_element() and theme_form_element_label().

 *

 * @see hook_element_info_alter()

 * @see system_element_info()

 */

function hook_element_info() {

  $types['filter_format'] = array(

    '#input' => TRUE,

  );

  return $types;

}

/**

 * Alter the element type information returned from modules.

 *

 * A module may implement this hook in order to alter the element type defaults

 * defined by a module.

 *

 * @param $type

 *   All element type defaults as collected by hook_element_info().

 *

 * @see hook_element_info()

 */

function hook_element_info_alter(&$type) {

  // Decrease the default size of textfields.

  if (isset($type['textfield']['#size'])) {

    $type['textfield']['#size'] = 40;

  }

}

/**

 * Perform cleanup tasks.

 *

 * This hook is run at the end of most regular page requests. It is often

 * used for page logging and specialized cleanup. This hook MUST NOT print

 * anything because by the time it runs the response is already sent to

 * the browser.

 *

 * Only use this hook if your code must run even for cached page views.

 * If you have code which must run once on all non-cached pages, use

 * hook_init() instead. That is the usual case. If you implement this hook

 * and see an error like 'Call to undefined function', it is likely that

 * you are depending on the presence of a module which has not been loaded yet.

 * It is not loaded because Drupal is still in bootstrap mode.

 *

 * @param $destination

 *   If this hook is invoked as part of a drupal_goto() call, then this argument

 *   will be a fully-qualified URL that is the destination of the redirect.

 */

function hook_exit($destination = NULL) {

  db_update('counter')

    ->expression('hits', 'hits + 1')

    ->condition('type', 1)

    ->execute();

}

/**

 * Perform necessary alterations to the JavaScript before it is presented on

 * the page.

 *

 * @param $javascript

 *   An array of all JavaScript being presented on the page.

 *

 * @see drupal_add_js()

 * @see drupal_get_js()

 * @see drupal_js_defaults()

 */

function hook_js_alter(&$javascript) {

  // Swap out jQuery to use an updated version of the library.

  $javascript['misc/jquery.js']['data'] = drupal_get_path('module', 'jquery_update') . '/jquery.js';

}

/**

 * Registers JavaScript/CSS libraries associated with a module.

 *

 * Modules implementing this return an array of arrays. The key to each

 * sub-array is the machine readable name of the library. Each library may

 * contain the following items:

 *

 * - 'title': The human readable name of the library.

 * - 'website': The URL of the library's web site.

 * - 'version': A string specifying the version of the library; intentionally

 *   not a float because a version like "1.2.3" is not a valid float. Use PHP's

 *   version_compare() to compare different versions.

 * - 'js': An array of JavaScript elements; each element's key is used as $data

 *   argument, each element's value is used as $options array for

 *   drupal_add_js(). To add library-specific (not module-specific) JavaScript

 *   settings, the key may be skipped, the value must specify

 *   'type' => 'setting', and the actual settings must be contained in a 'data'

 *   element of the value.

 * - 'css': Like 'js', an array of CSS elements passed to drupal_add_css().

 * - 'dependencies': An array of libraries that are required for a library. Each

 *   element is an array listing the module and name of another library. Note

 *   that all dependencies for each dependent library will also be added when

 *   this library is added.

 *

 * Registered information for a library should contain re-usable data only.

 * Module- or implementation-specific data and integration logic should be added

 * separately.

 *

 * @return

 *   An array defining libraries associated with a module.

 *

 * @see system_library()

 * @see drupal_add_library()

 * @see drupal_get_library()

 */

function hook_library() {

  // Library One.

  $libraries['library-1'] = array(

    'title' => 'Library One',

    'website' => 'http://example.com/library-1',

    'version' => '1.2',

    'js' => array(

      drupal_get_path('module', 'my_module') . '/library-1.js' => array(),

    ),

    'css' => array(

      drupal_get_path('module', 'my_module') . '/library-2.css' => array(

        'type' => 'file',

        'media' => 'screen',

      ),

    ),

  );

  // Library Two.

  $libraries['library-2'] = array(

    'title' => 'Library Two',

    'website' => 'http://example.com/library-2',

    'version' => '3.1-beta1',

    'js' => array(

      // JavaScript settings may use the 'data' key.

      array(

        'type' => 'setting',

        'data' => array('library2' => TRUE),

      ),

    ),

    'dependencies' => array(

      // Require jQuery UI core by System module.

      array('system', 'ui'),

      // Require our other library.

      array('my_module', 'library-1'),

      // Require another library.

      array('other_module', 'library-3'),

    ),

  );

  return $libraries;

}

/**

 * Alters the JavaScript/CSS library registry.

 *

 * Allows certain, contributed modules to update libraries to newer versions

 * while ensuring backwards compatibility. In general, such manipulations should

 * only be done by designated modules, since most modules that integrate with a

 * certain library also depend on the API of a certain library version.

 *

 * @param $libraries

 *   The JavaScript/CSS libraries provided by $module. Keyed by internal library

 *   name and passed by reference.

 * @param $module

 *   The name of the module that registered the libraries.

 *

 * @see hook_library()

 */

function hook_library_alter(&$libraries, $module) {

  // Update Farbtastic to version 2.0.

  if ($module == 'system' && isset($libraries['farbtastic'])) {

    // Verify existing version is older than the one we are updating to.

    if (version_compare($libraries['farbtastic']['version'], '2.0', '<')) {

      // Update the existing Farbtastic to version 2.0.

      $libraries['farbtastic']['version'] = '2.0';

      $libraries['farbtastic']['js'] = array(

        drupal_get_path('module', 'farbtastic_update') . '/farbtastic-2.0.js' => array(),

      );

    }

  }

}

/**

 * Alter CSS files before they are output on the page.

 *

 * @param $css

 *   An array of all CSS items (files and inline CSS) being requested on the page.

 *

 * @see drupal_add_css()

 * @see drupal_get_css()

 */

function hook_css_alter(&$css) {

  // Remove defaults.css file.

  unset($css[drupal_get_path('module', 'system') . '/defaults.css']);

}

/**

 * Alter the commands that are sent to the user through the Ajax framework.

 *

 * @param $commands

 *   An array of all commands that will be sent to the user.

 *

 * @see ajax_render()

 */

function hook_ajax_render_alter(&$commands) {

  // Inject any new status messages into the content area.

  $commands[] = ajax_command_prepend('#block-system-main .content', theme('status_messages'));

}

/**

 * Add elements to a page before it is rendered.

 *

 * Use this hook when you want to add elements at the page level. For your

 * additions to be printed, they have to be placed below a top level array key

 * of the $page array that has the name of a region of the active theme.

 *

 * By default, valid region keys are 'page_top', 'header', 'sidebar_first',

 * 'content', 'sidebar_second' and 'page_bottom'. To get a list of all regions

 * of the active theme, use system_region_list($theme). Note that $theme is a

 * global variable.

 *

 * If you want to alter the elements added by other modules or if your module

 * depends on the elements of other modules, use hook_page_alter() instead which

 * runs after this hook.

 *

 * @param $page

 *   Nested array of renderable elements that make up the page.

 *

 * @see hook_page_alter()

 * @see drupal_render_page()

 */

function hook_page_build(&$page) {

  if (menu_get_object('node', 1)) {

    // We are on a node detail page. Append a standard disclaimer to the

    // content region.

    $page['content']['disclaimer'] = array(

      '#markup' => t('Acme, Inc. is not responsible for the contents of this sample code.'),

      '#weight' => 25,

    );

  }

}

/**

 * Alter a menu router item right after it has been retrieved from the database or cache.

 *

 * This hook is invoked by menu_get_item() and allows for run-time alteration of router

 * information (page_callback, title, and so on) before it is translated and checked for

 * access. The passed-in $router_item is statically cached for the current request, so this

 * hook is only invoked once for any router item that is retrieved via menu_get_item().

 *

 * Usually, modules will only want to inspect the router item and conditionally

 * perform other actions (such as preparing a state for the current request).

 * Note that this hook is invoked for any router item that is retrieved by

 * menu_get_item(), which may or may not be called on the path itself, so implementations

 * should check the $path parameter if the alteration should fire for the current request

 * only.

 *

 * @param $router_item

 *   The menu router item for $path.

 * @param $path

 *   The originally passed path, for which $router_item is responsible.

 * @param $original_map

 *   The path argument map, as contained in $path.

 *

 * @see menu_get_item()

 */

function hook_menu_get_item_alter(&$router_item, $path, $original_map) {

  // When retrieving the router item for the current path...

  if ($path == $_GET['q']) {

    // ...call a function that prepares something for this request.

    mymodule_prepare_something();

  }

}

/**

 * Define menu items and page callbacks.

 *

 * This hook enables modules to register paths in order to define how URL

 * requests are handled. Paths may be registered for URL handling only, or they

 * can register a link to be placed in a menu (usually the Navigation menu). A

 * path and its associated information is commonly called a "menu router item".

 * This hook is rarely called (for example, when modules are enabled), and

 * its results are cached in the database.

 *

 * hook_menu() implementations return an associative array whose keys define

 * paths and whose values are an associative array of properties for each

 * path. (The complete list of properties is in the return value section below.)

 *

 * @section sec_callback_funcs Callback Functions

 * The definition for each path may include a page callback function, which is

 * invoked when the registered path is requested. If there is no other

 * registered path that fits the requested path better, any further path

 * components are passed to the callback function. For example, your module

 * could register path 'abc/def':

 * @code

 *   function mymodule_menu() {

 *     $items['abc/def'] = array(

 *       'page callback' => 'mymodule_abc_view',

 *     );

 *     return $items;

 *   }

 *

 *   function mymodule_abc_view($ghi = 0, $jkl = '') {

 *     // ...

 *   }

 * @endcode

 * When path 'abc/def' is requested, no further path components are in the

 * request, and no additional arguments are passed to the callback function (so

 * $ghi and $jkl would take the default values as defined in the function

 * signature). When 'abc/def/123/foo' is requested, $ghi will be '123' and

 * $jkl will be 'foo'. Note that this automatic passing of optional path

 * arguments applies only to page and theme callback functions.

 *

 * @subsection sub_callback_arguments Callback Arguments

 * In addition to optional path arguments, the page callback and other callback

 * functions may specify argument lists as arrays. These argument lists may

 * contain both fixed/hard-coded argument values and integers that correspond

 * to path components. When integers are used and the callback function is

 * called, the corresponding path components will be substituted for the

 * integers. That is, the integer 0 in an argument list will be replaced with

 * the first path component, integer 1 with the second, and so on (path

 * components are numbered starting from zero). To pass an integer without it

 * being replaced with its respective path component, use the string value of

 * the integer (e.g., '1') as the argument value. This substitution feature

 * allows you to re-use a callback function for several different paths. For

 * example:

 * @code

 *   function mymodule_menu() {

 *     $items['abc/def'] = array(

 *       'page callback' => 'mymodule_abc_view',

 *       'page arguments' => array(1, 'foo'),

 *     );

 *     return $items;

 *   }

 * @endcode

 * When path 'abc/def' is requested, the page callback function will get 'def'

 * as the first argument and (always) 'foo' as the second argument.

 *

 * If a page callback function uses an argument list array, and its path is

 * requested with optional path arguments, then the list array's arguments are

 * passed to the callback function first, followed by the optional path

 * arguments. Using the above example, when path 'abc/def/bar/baz' is requested,

 * mymodule_abc_view() will be called with 'def', 'foo', 'bar' and 'baz' as

 * arguments, in that order.

 *

 * Special care should be taken for the page callback drupal_get_form(), because

 * your specific form callback function will always receive $form and

 * &$form_state as the first function arguments:

 * @code

 *   function mymodule_abc_form($form, &$form_state) {

 *     // ...

 *     return $form;

 *   }

 * @endcode

 * See @link form_api Form API documentation @endlink for details.

 *

 * @section sec_path_wildcards Wildcards in Paths

 * @subsection sub_simple_wildcards Simple Wildcards

 * Wildcards within paths also work with integer substitution. For example,

 * your module could register path 'my-module/%/edit':

 * @code

 *   $items['my-module/%/edit'] = array(

 *     'page callback' => 'mymodule_abc_edit',

 *     'page arguments' => array(1),

 *   );

 * @endcode

 * When path 'my-module/foo/edit' is requested, integer 1 will be replaced

 * with 'foo' and passed to the callback function. Note that wildcards may not

 * be used as the first component.

 *

 * @subsection sub_autoload_wildcards Auto-Loader Wildcards

 * Registered paths may also contain special "auto-loader" wildcard components

 * in the form of '%mymodule_abc', where the '%' part means that this path

 * component is a wildcard, and the 'mymodule_abc' part defines the prefix for a

 * load function, which here would be named mymodule_abc_load(). When a matching

 * path is requested, your load function will receive as its first argument the

 * path component in the position of the wildcard; load functions may also be

 * passed additional arguments (see "load arguments" in the return value

 * section below). For example, your module could register path

 * 'my-module/%mymodule_abc/edit':

 * @code

 *   $items['my-module/%mymodule_abc/edit'] = array(

 *     'page callback' => 'mymodule_abc_edit',

 *     'page arguments' => array(1),

 *   );

 * @endcode

 * When path 'my-module/123/edit' is requested, your load function

 * mymodule_abc_load() will be invoked with the argument '123', and should

 * load and return an "abc" object with internal id 123:

 * @code

 *   function mymodule_abc_load($abc_id) {

 *     return db_query("SELECT * FROM {mymodule_abc} WHERE abc_id = :abc_id", array(':abc_id' => $abc_id))->fetchObject();

 *   }

 * @endcode

 * This 'abc' object will then be passed into the callback functions defined

 * for the menu item, such as the page callback function mymodule_abc_edit()

 * to replace the integer 1 in the argument array. Note that a load function

 * should return FALSE when it is unable to provide a loadable object. For

 * example, the node_load() function for the 'node/%node/edit' menu item will

 * return FALSE for the path 'node/999/edit' if a node with a node ID of 999

 * does not exist. The menu routing system will return a 404 error in this case.

 *

 * @subsection sub_argument_wildcards Argument Wildcards

 * You can also define a %wildcard_to_arg() function (for the example menu

 * entry above this would be 'mymodule_abc_to_arg()'). The _to_arg() function

 * is invoked to retrieve a value that is used in the path in place of the

 * wildcard. A good example is user.module, which defines

 * user_uid_optional_to_arg() (corresponding to the menu entry

 * 'tracker/%user_uid_optional'). This function returns the user ID of the

 * current user.

 *

 * The _to_arg() function will get called with three arguments:

 * - $arg: A string representing whatever argument may have been supplied by

 *   the caller (this is particularly useful if you want the _to_arg()

 *   function only supply a (default) value if no other value is specified,

 *   as in the case of user_uid_optional_to_arg().

 * - $map: An array of all path fragments (e.g. array('node','123','edit') for

 *   'node/123/edit').

 * - $index: An integer indicating which element of $map corresponds to $arg.

 *

 * _load() and _to_arg() functions may seem similar at first glance, but they

 * have different purposes and are called at different times. _load()

 * functions are called when the menu system is collecting arguments to pass

 * to the callback functions defined for the menu item. _to_arg() functions

 * are called when the menu system is generating links to related paths, such

 * as the tabs for a set of MENU_LOCAL_TASK items.

 *

 * @section sec_render_tabs Rendering Menu Items As Tabs

 * You can also make groups of menu items to be rendered (by default) as tabs

 * on a page. To do that, first create one menu item of type MENU_NORMAL_ITEM,

 * with your chosen path, such as 'foo'. Then duplicate that menu item, using a

 * subdirectory path, such as 'foo/tab1', and changing the type to

 * MENU_DEFAULT_LOCAL_TASK to make it the default tab for the group. Then add

 * the additional tab items, with paths such as "foo/tab2" etc., with type

 * MENU_LOCAL_TASK. Example:

 * @code

 * // Make "Foo settings" appear on the admin Config page

 * $items['admin/config/system/foo'] = array(

 *   'title' => 'Foo settings',

 *   'type' => MENU_NORMAL_ITEM,

 *   // Page callback, etc. need to be added here.

 * );

 * // Make "Tab 1" the main tab on the "Foo settings" page

 * $items['admin/config/system/foo/tab1'] = array(

 *   'title' => 'Tab 1',

 *   'type' => MENU_DEFAULT_LOCAL_TASK,

 *   // Access callback, page callback, and theme callback will be inherited

 *   // from 'admin/config/system/foo', if not specified here to override.

 * );

 * // Make an additional tab called "Tab 2" on "Foo settings"

 * $items['admin/config/system/foo/tab2'] = array(

 *   'title' => 'Tab 2',

 *   'type' => MENU_LOCAL_TASK,

 *   // Page callback and theme callback will be inherited from

 *   // 'admin/config/system/foo', if not specified here to override.

 *   // Need to add access callback or access arguments.

 * );

 * @endcode

 *

 * @return

 *   An array of menu items. Each menu item has a key corresponding to the

 *   Drupal path being registered. The corresponding array value is an

 *   associative array that may contain the following key-value pairs:

 *   - "title": Required. The untranslated title of the menu item.

 *   - "title callback": Function to generate the title; defaults to t().

 *     If you require only the raw string to be output, set this to FALSE.

 *   - "title arguments": Arguments to send to t() or your custom callback,

 *     with path component substitution as described above.

 *   - "description": The untranslated description of the menu item.

 *   - "page callback": The function to call to display a web page when the user

 *     visits the path. If omitted, the parent menu item's callback will be used

 *     instead.

 *   - "page arguments": An array of arguments to pass to the page callback

 *     function, with path component substitution as described above.

 *   - "delivery callback": The function to call to package the result of the

 *     page callback function and send it to the browser. Defaults to

 *     drupal_deliver_html_page() unless a value is inherited from a parent menu

 *     item. Note that this function is called even if the access checks fail,

 *     so any custom delivery callback function should take that into account.

 *     See drupal_deliver_html_page() for an example.

 *   - "access callback": A function returning TRUE if the user has access

 *     rights to this menu item, and FALSE if not. It can also be a boolean

 *     constant instead of a function, and you can also use numeric values

 *     (will be cast to boolean). Defaults to user_access() unless a value is

 *     inherited from the parent menu item; only MENU_DEFAULT_LOCAL_TASK items

 *     can inherit access callbacks. To use the user_access() default callback,

 *     you must specify the permission to check as 'access arguments' (see

 *     below).

 *   - "access arguments": An array of arguments to pass to the access callback

 *     function, with path component substitution as described above. If the

 *     access callback is inherited (see above), the access arguments will be

 *     inherited with it, unless overridden in the child menu item.

 *   - "theme callback": (optional) A function returning the machine-readable

 *     name of the theme that will be used to render the page. If not provided,

 *     the value will be inherited from a parent menu item. If there is no

 *     theme callback, or if the function does not return the name of a current

 *     active theme on the site, the theme for this page will be determined by

 *     either hook_custom_theme() or the default theme instead. As a general

 *     rule, the use of theme callback functions should be limited to pages

 *     whose functionality is very closely tied to a particular theme, since

 *     they can only be overridden by modules which specifically target those

 *     pages in hook_menu_alter(). Modules implementing more generic theme