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

modules/block/block.module, line 764

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][] = $record->rid;
    }
    foreach ($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($user->data['block'][$block->module][$block->delta])) {
                $enabled = $user->data['block'][$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) {
                // Convert the Drupal path to lowercase.
                $path = drupal_strtolower(drupal_get_path_alias($_GET['q']));
                // Compare the lowercase internal and lowercase path alias (if any).
                $page_match = drupal_match_path($path, $pages);
                if ($path != $_GET['q']) {
                    $page_match = $page_match || drupal_match_path($_GET['q'], $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]);
        }
    }
}