For Item Good, with nested Categories for Bootstrap 3 - breadcrumbs navigation bar

breadcrumbs.rb

  def goods_breadcrumbs(selected_category)

    # no matter how many levels category will have
    # we take parents tree
    parents_tree = selected_category.self_and_ancestors
    # and if category has children from next.level add one of them
    if selected_category.children.any?
      parents_tree << selected_category.children.first
    end

    levels = ''
    # and then siblings from every level
    parents_tree.each do |parent|
      level_content = ''
      # collect categories from each level into string as <li>link</li>
      parent.self_and_siblings.order(:name).each do |category|
        if category == parent &&  category.depth <= selected_category.depth
          level_content << content_tag(:li, category.name, class: 'active')
        else
          level_content << content_tag(:li, link_to(category.name, category_goods_path(category)))
        end

      end
      # wrap links into <ol> and push to levels
      levels << content_tag(:ol, raw(level_content) , class: 'breadcrumb')
    end
    return raw(levels)
  end