<?php

/**

 * @file

 * Controls the visual building blocks a page is constructed with.

 */

/**

 * Denotes that a block is not enabled in any region and should not be shown.

 */

define('BLOCK_REGION_NONE', -1);

/**

 * Users cannot control whether or not they see this block.

 */

define('BLOCK_CUSTOM_FIXED', 0);

/**

 * Shows this block by default, but lets individual users hide it.

 */

define('BLOCK_CUSTOM_ENABLED', 1);

/**

 * Hides this block by default but lets individual users show it.

 */

define('BLOCK_CUSTOM_DISABLED', 2);

/**

 * Shows this block on every page except the listed pages.

 */

define('BLOCK_VISIBILITY_NOTLISTED', 0);

/**

 * Shows this block on only the listed pages.

 */

define('BLOCK_VISIBILITY_LISTED', 1);

/**

 * Shows this block if the associated PHP code returns TRUE.

 */

define('BLOCK_VISIBILITY_PHP', 2);

/**

 * Implements hook_help().

 */

function block_help($path, $arg) {

  switch ($path) {

    case 'admin/help#block':

      $output = '';

      $output .= '<h3>' . t('About') . '</h3>';

      $output .= '<p>' . t('The Block module allows you to create boxes of content, which are rendered into an area, or region, of one or more pages of a website. The core Seven administration theme, for example, implements the regions "Content", "Help", "Dashboard main", and "Dashboard sidebar", and a block may appear in any one of these regions. The <a href="@blocks">Blocks administration page</a> provides a drag-and-drop interface for assigning a block to a region, and for controlling the order of blocks within regions. For more information, see the online handbook entry for <a href="@block">Block module</a>.', array('@block' => 'http://drupal.org/documentation/modules/block/', '@blocks' => url('admin/structure/block'))) . '</p>';

      $output .= '<h3>' . t('Uses') . '</h3>';

      $output .= '<dl>';

      $output .= '<dt>' . t('Positioning content') . '</dt>';

      $output .= '<dd>' . t('When working with blocks, remember that all themes do <em>not</em> implement the same regions, or display regions in the same way. Blocks are positioned on a per-theme basis. Users with the <em>Administer blocks</em> permission can disable blocks. Disabled blocks are listed on the <a href="@blocks">Blocks administration page</a>, but are not displayed in any region.', array('@block' => 'http://drupal.org/documentation/modules/block/', '@blocks' => url('admin/structure/block'))) . '</dd>';

      $output .= '<dt>' . t('Controlling visibility') . '</dt>';

      $output .= '<dd>' . t('Blocks can be configured to be visible only on certain pages, only to users of certain roles, or only on pages displaying certain <a href="@content-type">content types</a>. Administrators can also allow specific blocks to be enabled or disabled by users when they edit their <a href="@user">My account</a> page. Some dynamic blocks, such as those generated by modules, will be displayed only on certain pages.', array('@content-type' => url('admin/structure/types'), '@user' => url('user'))) . '</dd>';

      $output .= '<dt>' . t('Creating custom blocks') . '</dt>';

      $output .= '<dd>' . t('Users with the <em>Administer blocks</em> permission can <a href="@block-add">add custom blocks</a>, which are then listed on the <a href="@blocks">Blocks administration page</a>. Once created, custom blocks behave just like default and module-generated blocks.', array('@blocks' => url('admin/structure/block'), '@block-add' => url('admin/structure/block/add'))) . '</dd>';

      $output .= '</dl>';

      return $output;

    case 'admin/structure/block/add':

      return '<p>' . t('Use this page to create a new custom block.') . '</p>';

  }

  if ($arg[0] == 'admin' && $arg[1] == 'structure' && $arg['2'] == 'block' && (empty($arg[3]) || $arg[3] == 'list')) {

    $demo_theme = !empty($arg[4]) ? $arg[4] : variable_get('theme_default', 'bartik');

    $themes = list_themes();

    $output = '<p>' . t('This page provides a drag-and-drop interface for assigning a block to a region, and for controlling the order of blocks within regions. Since not all themes implement the same regions, or display regions in the same way, blocks are positioned on a per-theme basis. Remember that your changes will not be saved until you click the <em>Save blocks</em> button at the bottom of the page. Click the <em>configure</em> link next to each block to configure its specific title and visibility settings.') . '</p>';

    $output .= '<p>' . l(t('Demonstrate block regions (!theme)', array('!theme' => $themes[$demo_theme]->info['name'])), 'admin/structure/block/demo/' . $demo_theme) . '</p>';

    return $output;

  }

}

/**

 * Implements hook_theme().

 */

function block_theme() {

  return array(

    'block' => array(

      'render element' => 'elements',

      'template' => 'block',

    ),

    'block_admin_display_form' => array(

      'template' => 'block-admin-display-form',

      'file' => 'block.admin.inc',

      'render element' => 'form',

    ),

  );

}

/**

 * Implements hook_permission().

 */

function block_permission() {

  return array(

    'administer blocks' => array(

      'title' => t('Administer blocks'),

    ),

  );

}

/**

 * Implements hook_menu().

 */

function block_menu() {

  $default_theme = variable_get('theme_default', 'bartik');

  $items['admin/structure/block'] = array(

    'title' => 'Blocks',

    'description' => 'Configure what block content appears in your site\'s sidebars and other regions.',

    'page callback' => 'block_admin_display',

    'page arguments' => array($default_theme),

    'access arguments' => array('administer blocks'),

    'file' => 'block.admin.inc',

  );

  $items['admin/structure/block/manage/%/%'] = array(

    'title' => 'Configure block',

    'page callback' => 'drupal_get_form',

    'page arguments' => array('block_admin_configure', 4, 5),

    'access arguments' => array('administer blocks'),

    'file' => 'block.admin.inc',

  );

  $items['admin/structure/block/manage/%/%/configure'] = array(

    'title' => 'Configure block',

    'type' => MENU_DEFAULT_LOCAL_TASK,

    'context' => MENU_CONTEXT_INLINE,

  );

  $items['admin/structure/block/manage/%/%/delete'] = array(

    'title' => 'Delete block',

    'page callback' => 'drupal_get_form',

    'page arguments' => array('block_custom_block_delete', 4, 5),

    'access arguments' => array('administer blocks'),

    'type' => MENU_LOCAL_TASK,

    'context' => MENU_CONTEXT_NONE,

    'file' => 'block.admin.inc',

  );

  $items['admin/structure/block/add'] = array(

    'title' => 'Add block',

    'page callback' => 'drupal_get_form',

    'page arguments' => array('block_add_block_form'),

    'access arguments' => array('administer blocks'),

    'type' => MENU_LOCAL_ACTION,

    'file' => 'block.admin.inc',

  );

  foreach (list_themes() as $key => $theme) {

    $items['admin/structure/block/list/' . $key] = array(

      'title' => $theme->info['name'],

      'page arguments' => array($key),

      'type' => $key == $default_theme ? MENU_DEFAULT_LOCAL_TASK : MENU_LOCAL_TASK,

      'weight' => $key == $default_theme ? -10 : 0,

      'access callback' => '_block_themes_access',

      'access arguments' => array($theme),

      'file' => 'block.admin.inc',

    );

    if ($key != $default_theme) {

      $items['admin/structure/block/list/' . $key . '/add'] = array(

        'title' => 'Add block',

        'page callback' => 'drupal_get_form',

        'page arguments' => array('block_add_block_form'),

        'access arguments' => array('administer blocks'),

        'type' => MENU_LOCAL_ACTION,

        'file' => 'block.admin.inc',

      );

    }

    $items['admin/structure/block/demo/' . $key] = array(

      'title' => $theme->info['name'],

      'page callback' => 'block_admin_demo',

      'page arguments' => array($key),

      'type' => MENU_CALLBACK,

      'access callback' => '_block_themes_access',

      'access arguments' => array($theme),

      'theme callback' => '_block_custom_theme',

      'theme arguments' => array($key),

      'file' => 'block.admin.inc',

    );

  }

  return $items;

}

/**

 * Menu item access callback - only admin or enabled themes can be accessed.

 */

function _block_themes_access($theme) {

  return user_access('administer blocks') && drupal_theme_access($theme);

}

/**

 * Theme callback for the block configuration pages.

 *

 * @param $theme

 *   The theme whose blocks are being configured. If not set, the default theme

 *   is assumed.

 *

 * @return

 *   The theme that should be used for the block configuration page, or NULL

 *   to indicate that the default theme should be used.

 */

function _block_custom_theme($theme = NULL) {

  // We return exactly what was passed in, to guarantee that the page will

  // always be displayed using the theme whose blocks are being configured.

  return $theme;

}

/**

 * Implements hook_block_info().

 */

function block_block_info() {

  $blocks = array();

  $result = db_query('SELECT bid, info FROM {block_custom} ORDER BY info');

  foreach ($result as $block) {

    $blocks[$block->bid]['info'] = $block->info;

    // Not worth caching.

    $blocks[$block->bid]['cache'] = DRUPAL_NO_CACHE;

  }

  return $blocks;

}

/**

 * Implements hook_block_configure().

 */

function block_block_configure($delta = 0) {

  if ($delta) {

    $custom_block = block_custom_block_get($delta);

  }

  else {

    $custom_block = array();

  }

  return block_custom_block_form($custom_block);

}

/**

 * Implements hook_block_save().

 */

function block_block_save($delta = 0, $edit = array()) {

  block_custom_block_save($edit, $delta);

}

/**

 * Implements hook_block_view().

 *

 * Generates the administrator-defined blocks for display.

 */

function block_block_view($delta = '') {

  $block = db_query('SELECT body, format FROM {block_custom} WHERE bid = :bid', array(':bid' => $delta))->fetchObject();

  $data['subject'] = NULL;

  $data['content'] = check_markup($block->body, $block->format, '', TRUE);

  return $data;

}

/**

 * Implements hook_page_build().

 *

 * Renders blocks into their regions.

 */

function block_page_build(&$page) {

  global $theme;

  // The theme system might not yet be initialized. We need $theme.

  drupal_theme_initialize();

  // Fetch a list of regions for the current theme.

  $all_regions = system_region_list($theme);

  $item = menu_get_item();

  if ($item['path'] != 'admin/structure/block/demo/' . $theme) {

    // Load all region content assigned via blocks.

    foreach (array_keys($all_regions) as $region) {

      // Assign blocks to region.

      if ($blocks = block_get_blocks_by_region($region)) {

        $page[$region] = $blocks;

      }

    }

    // Once we've finished attaching all blocks to the page, clear the static

    // cache to allow modules to alter the block list differently in different

    // contexts. For example, any code that triggers hook_page_build() more

    // than once in the same page request may need to alter the block list

    // differently each time, so that only certain parts of the page are

    // actually built. We do not clear the cache any earlier than this, though,

    // because it is used each time block_get_blocks_by_region() gets called

    // above.

    drupal_static_reset('block_list');

  }

  else {

    // Append region description if we are rendering the regions demo page.

    $item = menu_get_item();

    if ($item['path'] == 'admin/structure/block/demo/' . $theme) {

      foreach (system_region_list($theme, REGIONS_VISIBLE, FALSE) as $region) {

        $description = '<div class="block-region">' . $all_regions[$region] . '</div>';

        $page[$region]['block_description'] = array(

          '#markup' => $description,

          '#weight' => 15,

        );

      }

      $page['page_top']['backlink'] = array(

        '#type' => 'link',

        '#title' => t('Exit block region demonstration'),

        '#href' => 'admin/structure/block' . (variable_get('theme_default', 'bartik') == $theme ? '' : '/list/' . $theme),

        // Add the "overlay-restore" class to indicate this link should restore

        // the context in which the region demonstration page was opened.

        '#options' => array('attributes' => array('class' => array('block-demo-backlink', 'overlay-restore'))),

        '#weight' => -10,

      );

    }

  }

}

/**

 * Gets a renderable array of a region containing all enabled blocks.

 *

 * @param $region

 *   The requested region.

 *

 * @return

 *   A renderable array of a region containing all enabled blocks.

 */

function block_get_blocks_by_region($region) {

  $build = array();

  if ($list = block_list($region)) {

    $build = _block_get_renderable_array($list);

  }

  return $build;

}

/**

 * Gets an array of blocks suitable for drupal_render().

 *

 * @param $list

 *   A list of blocks such as that returned by block_list().

 *

 * @return

 *   A renderable array.

 */

function _block_get_renderable_array($list = array()) {

  $weight = 0;

  $build = array();

  foreach ($list as $key => $block) {

    $build[$key] = $block->content;

    unset($block->content);

    // Add contextual links for this block; skip the main content block, since

    // contextual links are basically output as tabs/local tasks already. Also

    // skip the help block, since we assume that most users do not need or want

    // to perform contextual actions on the help block, and the links needlessly

    // draw attention on it.

    if ($key != 'system_main' && $key != 'system_help') {

      $build[$key]['#contextual_links']['block'] = array(

        'admin/structure/block/manage',

        array($block->module, $block->delta),

      );

    }

    $build[$key] += array(

      '#block' => $block,

      '#weight' => ++$weight,

    );

    $build[$key]['#theme_wrappers'][] = 'block';

  }

  $build['#sorted'] = TRUE;

  return $build;

}

/**

 * Updates the 'block' DB table with the blocks currently exported by modules.

 *

 * @param $theme

 *   The theme to rehash blocks for. If not provided, defaults to the currently

 *   used theme.

 *

 * @return

 *   Blocks currently exported by modules.

 */

function _block_rehash($theme = NULL) {

  global $theme_key;

  drupal_theme_initialize();

  if (!isset($theme)) {

    // If theme is not specifically set, rehash for the current theme.

    $theme = $theme_key;

  }

  $regions = system_region_list($theme);

  // These are the blocks the function will return.

  $blocks = array();

  // These are the blocks defined by code and modified by the database.

  $current_blocks = array();

  // These are {block}.bid values to be kept.

  $bids = array();

  $or = db_or();

  // Gather the blocks defined by modules.

  foreach (module_implements('block_info') as $module) {

    $module_blocks = module_invoke($module, 'block_info');

    $delta_list = array();

    foreach ($module_blocks as $delta => $block) {

      // Compile a condition to retrieve this block from the database.

      // Add identifiers.

      $delta_list[] = $delta;

      $block['module'] = $module;

      $block['delta'] = $delta;

      $block['theme'] = $theme;

      $current_blocks[$module][$delta] = $block;

    }

    if (!empty($delta_list)) {

      $condition = db_and()->condition('module', $module)->condition('delta', $delta_list);

      $or->condition($condition);

    }

  }

  // Save the blocks defined in code for alter context.

  $code_blocks = $current_blocks;

  $database_blocks = db_select('block', 'b', array('fetch' => PDO::FETCH_ASSOC))

    ->fields('b')

    ->condition($or)

    ->condition('theme', $theme)

    ->execute();

  $original_database_blocks = array();

  foreach ($database_blocks as $block) {

    $module = $block['module'];

    $delta = $block['delta'];

    $original_database_blocks[$module][$delta] = $block;

    // The cache mode can only by set from hook_block_info(), so that has

    // precedence over the database's value.

    if (isset($current_blocks[$module][$delta]['cache'])) {

      $block['cache'] = $current_blocks[$module][$delta]['cache'];

    }

    // Preserve info which is not in the database.

    $block['info'] = $current_blocks[$module][$delta]['info'];

    // Blocks stored in the database override the blocks defined in code.

    $current_blocks[$module][$delta] = $block;

    // Preserve this block.

    $bids[$block['bid']] = $block['bid'];

  }

  drupal_alter('block_info', $current_blocks, $theme, $code_blocks);

  foreach ($current_blocks as $module => $module_blocks) {

    foreach ($module_blocks as $delta => $block) {

      // Make sure certain attributes are set.

      $block += array(

        'pages' => '',

        'weight' => 0,

        'status' => 0,

      );

      // Check for active blocks in regions that are not available.

      if (!empty($block['region']) && $block['region'] != BLOCK_REGION_NONE && !isset($regions[$block['region']]) && $block['status'] == 1) {

        drupal_set_message(t('The block %info was assigned to the invalid region %region and has been disabled.', array('%info' => $block['info'], '%region' => $block['region'])), 'warning');

        // Disabled modules are moved into the BLOCK_REGION_NONE later so no

        // need to move the block to another region.

        $block['status'] = 0;

      }

      // Set region to none if not enabled.

      if (empty($block['status'])) {

        $block['status'] = 0;

        $block['region'] = BLOCK_REGION_NONE;

      }

      // There is no point saving disabled blocks. Still, we need to save them

      // because the 'title' attribute is saved to the {blocks} table.

      if (isset($block['bid'])) {

        // If the block has a bid property, it comes from the database and

        // the record needs to be updated, so set the primary key to 'bid'

        // before passing to drupal_write_record().

        $primary_keys = array('bid');

        // Remove a block from the list of blocks to keep if it became disabled.

        unset($bids[$block['bid']]);

      }

      else {

        $primary_keys = array();

      }

      // If the block is new or differs from the original database block, save

      // it. To determine whether there was a change it is enough to examine

      // the values for the keys in the original database record as that

      // contained every database field.

      if (!$primary_keys || array_diff_assoc($original_database_blocks[$module][$delta], $block)) {

        drupal_write_record('block', $block, $primary_keys);

        // Make it possible to test this.

        $block['saved'] = TRUE;

      }

      // Add to the list of blocks we return.

      $blocks[] = $block;

    }

  }

  if ($bids) {

    // Remove disabled that are no longer defined by the code from the

    // database.

    db_delete('block')

      ->condition('bid', $bids, 'NOT IN')

      ->condition('theme', $theme)

      ->execute();

  }

  return $blocks;

}

/**

 * Returns information from database about a user-created (custom) block.

 *

 * @param $bid

 *   ID of the block to get information for.

 *

 * @return

 *   Associative array of information stored in the database for this block.

 *   Array keys:

 *   - bid: Block ID.

 *   - info: Block description.

 *   - body: Block contents.

 *   - format: Filter ID of the filter format for the body.

 */

function block_custom_block_get($bid) {

  return db_query("SELECT * FROM {block_custom} WHERE bid = :bid", array(':bid' => $bid))->fetchAssoc();

}

/**

 * Form constructor for the custom block form.

 *

 * @param $edit

 *   (optional) An associative array of information retrieved by

 *   block_custom_get_block() if an existing block is being edited, or an empty

 *   array otherwise. Defaults to array().

 *

 * @ingroup forms

 */

function block_custom_block_form($edit = array()) {

  $edit += array(

    'info' => '',

    'body' => '',

  );

  $form['info'] = array(

    '#type' => 'textfield',

    '#title' => t('Block description'),

    '#default_value' => $edit['info'],

    '#maxlength' => 64,

    '#description' => t('A brief description of your block. Used on the <a href="@overview">Blocks administration page</a>.', array('@overview' => url('admin/structure/block'))),

    '#required' => TRUE,