function block_block_list_alter

Implements hook_block_list_alter().

Checks the page, user role, and user-specific visibility settings. Removes the block if the visibility conditions are not met.

File

drupal/core/modules/block/block.module, line 792
Controls the visual building blocks a page is constructed with.

Code

function block_block_list_alter(&$blocks) {
  global $user, $theme_key;

  // Build an array of roles for each block.
  $block_roles = array();
  $result = db_query('SELECT module, delta, rid FROM {block_role}');
  foreach ($result as $record) {
    $block_roles[$record->module][$record->delta][] = $record->rid;
  }

  // Build an array of langcodes allowed per block.
  $result = db_query('SELECT module, delta, type, langcode FROM {block_language}');
  $block_langcodes = array();
  foreach ($result as $record) {
    $block_langcodes[$record->module][$record->delta][$record->type][$record->langcode] = TRUE;
  }
  if ($user->uid) {
    $user_data = drupal_container()
      ->get('user.data')
      ->get('block', $user->uid, 'block');
  }
  foreach ($blocks as $key => $block) {
    if (!isset($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 a block has no roles associated, it is displayed for every role.
    // For blocks with roles associated, if none of the user's roles matches
    // the settings from this block, remove it from the block list.
    if (isset($block_roles[$block->module][$block->delta]) && !array_intersect($block_roles[$block->module][$block->delta], array_keys($user->roles))) {

      // No match.
      unset($blocks[$key]);
      continue;
    }

    // Use the user's block visibility setting, if necessary.
    if ($block->custom != BLOCK_CUSTOM_FIXED) {
      if ($user->uid && isset($user_data[$block->module][$block->delta])) {
        $enabled = $user_data[$block->module][$block->delta];
      }
      else {
        $enabled = $block->custom == BLOCK_CUSTOM_ENABLED;
      }
    }
    else {
      $enabled = TRUE;
    }

    // Limited visibility blocks must list at least one page.
    if ($block->visibility == BLOCK_VISIBILITY_LISTED && empty($block->pages)) {
      $enabled = FALSE;
    }
    if (!$enabled) {
      unset($blocks[$key]);
      continue;
    }

    // Match path if necessary.
    if ($block->pages) {

      // Convert path to lowercase. This allows comparison of the same path
      // with different case. Ex: /Page, /page, /PAGE.
      $pages = drupal_strtolower($block->pages);
      if ($block->visibility < BLOCK_VISIBILITY_PHP) {

        // Compare the lowercase path alias (if any) and internal path.
        $path = current_path();
        $path_alias = drupal_strtolower(drupal_container()
          ->get('path.alias_manager')
          ->getPathAlias($path));
        $page_match = drupal_match_path($path_alias, $pages) || $path != $path_alias && drupal_match_path($path, $pages);

        // When $block->visibility has a value of 0 (BLOCK_VISIBILITY_NOTLISTED),
        // the block is displayed on all pages except those listed in $block->pages.
        // When set to 1 (BLOCK_VISIBILITY_LISTED), it is displayed only on those
        // pages listed in $block->pages.
        $page_match = !($block->visibility xor $page_match);
      }
      elseif (module_exists('php')) {
        $page_match = php_eval($block->pages);
      }
      else {
        $page_match = FALSE;
      }
    }
    else {
      $page_match = TRUE;
    }
    if (!$page_match) {
      unset($blocks[$key]);
      continue;
    }

    // Language visibility settings.
    // No language setting for this block, leave it in the list.
    if (!isset($block_langcodes[$block->module][$block->delta])) {
      continue;
    }
    foreach ($block_langcodes[$block->module][$block->delta] as $language_type => $langcodes) {
      if (isset($langcodes[language($language_type)->langcode])) {

        // Found a language type - langcode combination in the configuration
        // that is applicable to the current request.
        continue 2;
      }
    }

    // Had language configuration but none matched.
    unset($blocks[$key]);
  }
}