<?php
// $Id: mongodb_block.api.php,v 1.4 2010-02-24 21:17:50 chx Exp $

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

/**
 * @addtogroup hooks
 * @{
 */

/**
 * Define all blocks provided by the module.
 *
 * Any module can export a block (or blocks) to be displayed by defining
 * the _block hook. This hook is called by theme.inc to display a block,
 * and also by block.module to procure the list of available blocks.
 *
 * @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:
 *   - 'status': TRUE, otherwise this block is ignored.
 *   - 'region': Required name of the region this block is in.
 *   - 'pages': an array of menu paths where the block should appear.
 *     Example: array('admin', 'node/%/edit') will display the block on admin,
 *     admin/structure etc. and the node edit pages.
 *   - 'node_type': List of node types. The block will appear only on node/%
 *     pages with the specified node types.
 *   - 'cache': A bitmask of flags describing how the block should behave with
 *     respect to block caching. The following shortcut bitmasks are provided
 *     as constants in common.inc:
 *     - 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_NO_CACHE: The block should not get cached.
 *   - 'weight': explicit weight of the block.
 */
function hook_block_info() {
  $blocks['exciting'] = array(
    'info' => t('An exciting block provided by Mymodule.'),
    'weight' => 0,
    'status' => 1,
    'region' => 'sidebar_first',
    // DRUPAL_CACHE_PER_ROLE will be assumed for block 0.
  );

  $blocks['amazing'] = array(
    'info' => t('An amazing block provided by Mymodule.'),
    'cache' => DRUPAL_CACHE_PER_ROLE | DRUPAL_CACHE_PER_PAGE,
  );

  return $blocks;
}

/**
 * Alters the information collected in hook_block_info.
 *
 * The core hook_block_info_alter is run-time, not supported. This is build
 * time.
 *
 * @param $blocks
 *   Assocative array, key is the module name, value is the hook_block_info
 *   returned by the module. As Drupal core and contrib rarely sets status
 *   and region this hook should be used to enable those.
 */
function hook_mongodb_block_info_alter(&$blocks) {
  // Enable the management block.
  $blocks['system']['management']['status'] = 1;
  $blocks['system']['management']['region'] = 'sidebar_first';
}

/**
 * Process the block when enabled in a region in order to view its contents.
 *
 * @param $delta
 *   Which block to return. This is a descriptive string used to identify
 *   blocks within each module and also within the theme system.
 *   The $delta for each block is defined within the array that your module
 *   returns when the hook_block_info() implementation is called.
 * @return
 *   An array which must define a 'subject' element and a 'content' element
 *   defining the block indexed by $delta.
 *
 * The functions mymodule_display_block_exciting and _amazing, as used in the
 * example, should of course be defined somewhere in your module and return the
 * content you want to display to your users. If the "content" element is empty,
 * no block will be displayed even if "subject" is present.
 *
 * For a detailed usage example, see block_example.module.
 */
function hook_block_view($delta = '') {
  switch ($delta) {
    case 'exciting':
      $block = array(
        'subject' => t('Default title of the exciting block'),
        'content' => mymodule_display_block_exciting(),
      );
      break;

    case 'amazing':
      $block = array(
        'subject' => t('Default title of the amazing block'),
        'content' => mymodule_display_block_amazing(),
      );
      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
 *   An array of data, as returned from the hook_block_view() implementation of
 *   the module that defined the block:
 *   - 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 $block
 *   The block object, as loaded from the database, having the main properties:
 *   - module: The name of the module that defined the block.
 *   - delta: The identifier for the block within that module, as defined within
 *     hook_block_info().
 *
 * @see hook_block_view_alter()
 * @see hook_block_view()
 */
function hook_block_view_alter(&$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().
 *
 * Note that this hook fires before hook_block_view_alter(). Therefore, all
 * implementations of hook_block_view_MODULE_DELTA_alter() will run before all
 * implementations of hook_block_view_alter(), regardless of the module order.
 *
 * @param $data
 *   An array of data, as returned from the hook_block_view() implementation of
 *   the module that defined the block:
 *   - 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 $block
 *   The block object, as loaded from the database, having the main properties:
 *   - module: The name of the module that defined the block.
 *   - delta: The identifier for the block within that module, as defined within
 *     hook_block_info().
 *
 * @see hook_block_view_alter()
 * @see hook_block_view()
 */
function hook_block_view_MODULE_DELTA_alter(&$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');
}

/**
 * @} End of "addtogroup hooks".
 */