<?php
/**
* @file
* Hooks provided by the Block module.
*/
/**
* @addtogroup hooks
* @{
*/
/**
* Define all blocks provided by the module.
*
* This hook declares to Drupal what blocks are provided by your module and can
* optionally specify initial block configuration settings.
*
* In hook_block_info(), each block your module provides is given a unique
* identifier referred to as "delta" (the array key in the return value). Delta
* values only need to be unique within your module, and they are used in the
* following ways:
* - Passed into the other block hooks in your module as an argument to identify
* the block being configured or viewed.
* - Used to construct the default HTML ID of "block-MODULE-DELTA" applied to
* each block when it is rendered. This ID may then be used for CSS styling or
* JavaScript programming.
* - Used to define a theming template suggestion of block__MODULE__DELTA, for
* advanced theming possibilities.
* - Used by other modules to identify your block in hook_block_info_alter() and
* other alter hooks.
* The values of delta can be strings or numbers, but because of the uses above
* it is preferable to use descriptive strings whenever possible, and only use a
* numeric identifier if you have to (for instance if your module allows users
* to create several similar blocks that you identify within your module code
* with numeric IDs). The maximum length for delta values is 32 bytes.
*
* @return
* An associative array whose keys define the delta for each block and whose
* values contain the block descriptions. Each block description is itself an
* associative array, with the following key-value pairs:
* - info: (required) The human-readable administrative name of the block.
* This is used to identify the block on administration screens, and is not
* displayed to non-administrative users.
* - cache: (optional) A bitmask describing what kind of caching is
* appropriate for the block. Drupal provides the following bitmask
* constants for defining cache granularity:
* - DRUPAL_CACHE_PER_ROLE (default): The block can change depending on the
* roles the user viewing the page belongs to.
* - DRUPAL_CACHE_PER_USER: The block can change depending on the user
* viewing the page. This setting can be resource-consuming for sites with
* large number of users, and should only be used when
* DRUPAL_CACHE_PER_ROLE is not sufficient.
* - DRUPAL_CACHE_PER_PAGE: The block can change depending on the page being
* viewed.
* - DRUPAL_CACHE_GLOBAL: The block is the same for every user on every page
* where it is visible.
* - DRUPAL_CACHE_CUSTOM: The module implements its own caching system.
* - DRUPAL_NO_CACHE: The block should not get cached.
* - properties: (optional) Array of additional metadata to add to the block.
* Common properties include:
* - administrative: Boolean that categorizes this block as usable in an
* administrative context. This might include blocks that help an
* administrator approve/deny comments, or view recently created user
* accounts.
* - weight: (optional) Initial value for the ordering weight of this block.
* Most modules do not provide an initial value, and any value provided can
* be modified by a user on the block configuration screen.
* - status: (optional) Initial value for block enabled status. (1 = enabled,
* 0 = disabled). Most modules do not provide an initial value, and any
* value provided can be modified by a user on the block configuration
* screen.
* - region: (optional) Initial value for theme region within which this
* block is set. Most modules do not provide an initial value, and any value
* provided can be modified by a user on the block configuration screen.
* Note: If you set a region that isn't available in the currently enabled
* theme, the block will be disabled.
* - visibility: (optional) Initial value for the visibility flag, which tells
* how to interpret the 'pages' value. Possible values are:
* - BLOCK_VISIBILITY_NOTLISTED: Show on all pages except listed pages.
* 'pages' lists the paths where the block should not be shown.
* - BLOCK_VISIBILITY_LISTED: Show only on listed pages. 'pages' lists the
* paths where the block should be shown.
* - BLOCK_VISIBILITY_PHP: Use custom PHP code to determine visibility.
* 'pages' gives the PHP code to use.
* Most modules do not provide an initial value for 'visibility' or 'pages',
* and any value provided can be modified by a user on the block
* configuration screen.
* - pages: (optional) See 'visibility' above. A string that contains one or
* more page paths separated by "\n", "\r", or "\r\n" when 'visibility' is
* set to BLOCK_VISIBILITY_NOTLISTED or BLOCK_VISIBILITY_LISTED (example:
* "<front>\nnode/1"), or custom PHP code when 'visibility' is set to
* BLOCK_VISIBILITY_PHP. Paths may use '*' as a wildcard (matching any
* number of characters); '<front>' designates the site's front page. For
* BLOCK_VISIBILITY_PHP, the PHP code's return value should be TRUE if the
* block is to be made visible or FALSE if the block should not be visible.
*
* For a detailed usage example, see block_example.module.
*
* @see hook_block_configure()
* @see hook_block_save()
* @see hook_block_view()
* @see hook_block_info_alter()
*/
function hook_block_info() {
// This example comes from node.module.
$blocks['syndicate'] = array(
'info' => t('Syndicate'),
'cache' => DRUPAL_NO_CACHE
);
$blocks['recent'] = array(
'info' => t('Recent content'),
// DRUPAL_CACHE_PER_ROLE will be assumed.
);
return $blocks;
}
/**
* Change block definition before saving to the database.
*
* @param $blocks
* A multidimensional array of blocks keyed by the defining module and delta;
* the values are blocks returned by hook_block_info(). This hook is fired
* after the blocks are collected from hook_block_info() and the database,
* right before saving back to the database.
* @param $theme
* The theme these blocks belong to.
* @param $code_blocks
* The blocks as defined in hook_block_info() before being overwritten by the
* database data.
*
* @see hook_block_info()
*/
function hook_block_info_alter(&$blocks, $theme, $code_blocks) {
// Disable the login block.
$blocks['user']['login']['status'] = 0;
}
/**
* Define a configuration form for a block.
*
* @param $delta
* Which block is being configured. This is a unique identifier for the block
* within the module, defined in hook_block_info().
*
* @return
* A configuration form, if one is needed for your block beyond the standard
* elements that the block module provides (block title, visibility, etc.).
*
* For a detailed usage example, see block_example.module.
*
* @see hook_block_info()
* @see hook_block_save()
*/
function hook_block_configure($delta = '') {
// This example comes from node.module.
$form = array();
if ($delta == 'recent') {
$form['node_recent_block_count'] = array(
'#type' => 'select',
'#title' => t('Number of recent content items to display'),
'#default_value' => variable_get('node_recent_block_count', 10),
'#options' => drupal_map_assoc(array(2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30)),
);
}
return $form;
}
/**
* Save the configuration options from hook_block_configure().
*
* This hook allows you to save the block-specific configuration settings
* defined within your hook_block_configure().
*
* @param $delta
* Which block is being configured. This is a unique identifier for the block
* within the module, defined in hook_block_info().
* @param $edit
* The submitted form data from the configuration form.
*
* For a detailed usage example, see block_example.module.
*
* @see hook_block_configure()
* @see hook_block_info()
*/
function hook_block_save($delta = '', $edit = array()) {
// This example comes from node.module.
if ($delta == 'recent') {
variable_set('node_recent_block_count', $edit['node_recent_block_count']);
}
}
/**
* Return a rendered or renderable view of a block.
*
* @param $delta
* Which block to render. This is a unique identifier for the block
* within the module, defined in hook_block_info().
*
* @return
* Either an empty array so the block will not be shown or an array containing
* the following elements:
* - subject: The default localized title of the block. If the block does not
* have a default title, this should be set to NULL.
* - content: The content of the block's body. This may be a renderable array
* (preferable) or a string containing rendered HTML content. If the content
* is empty the block will not be shown.
*
* For a detailed usage example, see block_example.module.
*
* @see hook_block_info()
* @see hook_block_view_alter()
* @see hook_block_view_MODULE_DELTA_alter()
*/
function hook_block_view($delta = '') {
// This example is adapted from node.module.
$block = array();
switch ($delta) {
case 'syndicate':
$block['subject'] = t('Syndicate');
$block['content'] = array(
'#theme' => 'feed_icon',
'#url' => 'rss.xml',
'#title' => t('Syndicate'),
);
break;
case 'recent':
if (user_access('access content')) {
$block['subject'] = t('Recent content');
if ($nodes = node_get_recent(variable_get('node_recent_block_count', 10))) {
$block['content'] = array(
'#theme' => 'node_recent_block',
'#nodes' => $nodes,
);
} else {
$block['content'] = t('No content available.');
}
}
break;
}
return $block;
}
/**
* Perform alterations to the content of a block.
*
* This hook allows you to modify any data returned by hook_block_view().
*
* Note that instead of hook_block_view_alter(), which is called for all
* blocks, you can also use hook_block_view_MODULE_DELTA_alter() to alter a
* specific block.
*
* @param $data
* The data as returned from the hook_block_view() implementation of the
* module that defined the block. This could be an empty array or NULL value
* (if the block is empty) or an array containing:
* - subject: The default localized title of the block.
* - content: Either a string or a renderable array representing the content
* of the block. You should check that the content is an array before trying
* to modify parts of the renderable structure.
* @param $block
* The block object, as loaded from the database, having the main properties:
* - module: The name of the module that defined the block.
* - delta: The unique identifier for the block within that module, as defined
* in hook_block_info().
*
* @see hook_block_view_MODULE_DELTA_alter()
* @see hook_block_view()
*/
function hook_block_view_alter(&$data, $block) {
// Remove the contextual links on all blocks that provide them.
if (is_array($data['content']) && isset($data['content']['#contextual_links'])) {
unset($data['content']['#contextual_links']);
}
// Add a theme wrapper function defined by the current module to all blocks
// provided by the "somemodule" module.
if (is_array($data['content']) && $block->module == 'somemodule') {
$data['content']['#theme_wrappers'][] = 'mymodule_special_block';
}
}
/**
* Perform alterations to a specific block.
*
* Modules can implement hook_block_view_MODULE_DELTA_alter() to modify a
* specific block, rather than implementing hook_block_view_alter().
*
* @param $data
* The data as returned from the hook_block_view() implementation of the
* module that defined the block. This could be an empty array or NULL value
* (if the block is empty) or an array containing:
* - subject: The localized title of the block.
* - content: Either a string or a renderable array representing the content
* of the block. You should check that the content is an array before trying
* to modify parts of the renderable structure.
* @param $block
* The block object, as loaded from the database, having the main properties:
* - module: The name of the module that defined the block.
* - delta: The unique identifier for the block within that module, as defined
* in hook_block_info().
*
* @see hook_block_view_alter()
* @see hook_block_view()
*/
function hook_block_view_MODULE_DELTA_alter(&$data, $block) {
// This code will only run for a specific block. For example, if MODULE_DELTA
// in the function definition above is set to "mymodule_somedelta", the code
// will only run on the "somedelta" block provided by the "mymodule" module.
// Change the title of the "somedelta" block provided by the "mymodule"
// module.
$data['subject'] = t('New title of the block');
}
/**
* Act on blocks prior to rendering.
*
* This hook allows you to add, remove or modify blocks in the block list. The
* block list contains the block definitions, not the rendered blocks. The
* blocks are rendered after the modules have had a chance to manipulate the
* block list.
*
* You can also set $block->content here, which will override the content of the
* block and prevent hook_block_view() from running.
*
* @param $blocks
* An array of $blocks, keyed by the block ID.
*/
function hook_block_list_alter(&$blocks) {
global $language, $theme_key;
// This example shows how to achieve language specific visibility setting for
// blocks.
$result = db_query('SELECT module, delta, language FROM {my_table}');
$block_languages = array();
foreach ($result as $record) {
$block_languages[$record->module][$record->delta][$record->language] = TRUE;
}
foreach ($blocks as $key => $block) {
// Any module using this alter should inspect the data before changing it,
// to ensure it is what they expect.
if (!isset($block->theme) || !isset($block->status) || $block->theme != $theme_key || $block->status != 1) {
// This block was added by a contrib module, leave it in the list.
continue;
}
if (!isset($block_languages[$block->module][$block->delta])) {
// No language setting for this block, leave it in the list.
continue;
}
if (!isset($block_languages[$block->module][$block->delta][$language->language])) {
// This block should not be displayed with the active language, remove
// from the list.
unset($blocks[$key]);
}
}
}
/**
* Act on block cache ID (cid) parts before the cid is generated.
*
* This hook allows you to add, remove or modify the custom keys used to
* generate a block cache ID (by default, these keys are set to the block
* module and delta). These keys will be combined with the standard ones
* provided by drupal_render_cid_parts() to generate the final block cache ID.
*
* To change the cache granularity used by drupal_render_cid_parts(), this hook
* cannot be used; instead, set the 'cache' key in the block's definition in
* hook_block_info().
*
* @params $cid_parts
* An array of elements used to build the cid.
* @param $block
* The block object being acted on.
*
* @see _block_get_cache_id()
*/
function hook_block_cid_parts_alter(&$cid_parts, $block) {
global $user;
// This example shows how to cache a block based on the user's timezone.
$cid_parts[] = $user->timezone;
}
/**
* @} End of "addtogroup hooks".
*/