protected function _filterBlock(Block $block)
    {
        $cacheKey = "allowed_{$block->id}";
        $cache = static::cache($cacheKey);

        if ($cache !== null) {
            return $cache;
        }

        if (!empty($block->locale) &&
            !in_array(I18n::locale(), (array)$block->locale)
        ) {
            return static::cache($cacheKey, false);
        }

        if (!$block->isAccessibleByUser()) {
            return static::cache($cacheKey, false);
        }

        $allowed = false;
        switch ($block->visibility) {
            case 'except':
                // Show on all pages except listed pages
                $allowed = !$this->_urlMatch($block->pages);
                break;
            case 'only':
                // Show only on listed pages
                $allowed = $this->_urlMatch($block->pages);
                break;
            case 'php':
                // Use custom PHP code to determine visibility
                $allowed = php_eval($block->pages, [
                    'view' => &$this->_View,
                    'block' => &$block
                ]) === true;
                break;
        }

        if (!$allowed) {
            return static::cache($cacheKey, false);
        }

        return static::cache($cacheKey, true);
    }