我 google 了好多都没成功

# application.html.erb
<div id='notice'>
    <%= render :partial => 'layouts/flash' , :locals => { :flash => flash } %>
</div>

# layouts/_flash.html.erb
<% flash.each do |name, msg| %>
  <div class="alert-message info">
      <a class="close dismiss" href="#">x</a>
      <p><%= msg %></p>
  </div>          
<% end %>

# controller
def active
        respond_to do |format|
            if @groupon_item.active
                @groupon_item.update_attributes(active: false)
                format.js {
                    flash.now[:success] = "商品已下架"
                    render action: 'active', status: :active, location: @groupon_item
                }
            else
                @groupon_item.update_attributes(active: true)
                format.js {
                    flash.now[:success] = "商品已上架！"
                    render action: 'active', status: :active, location: @groupon_item
                 }
            end
        end
    end

# view
<%= button_to active_text, active_commission_groupon_path(groupon_item), remote: true, method: :patch, data: { confirm: '确定此操作?' }, class: "btn btn-white" %>

# active.js.erb
$("#notice").html("<%= escape_javascript(render :partial => 'layouts/flash' , :locals => { :flash => flash }).html_safe %>");