def li_page_active_if(condition, attributes = {}, &block)
      if condition
        attributes[:class] ||= ''
        attributes[:class] += " active"
      end
      content_tag("li", attributes, &block)
    end
def li_page_active_if(condition, attributes = {}, &block)
      if condition
        attributes[:class] ||= ''
        attributes[:class] += " active"
      end
      content_tag("li", attributes, &block)
    end
page sidebar navigation