在Rails中提交bootstrap模式表单后，如何显示有错误的模式？

def create
  @user = User.new(user_params)
  if @user.save
    # 保存成功的逻辑
  else
    render 'new'
  end
end

<%= form_for @user do |f| %>
  <% if @user.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@user.errors.count, "error") %> prohibited this user from being saved:</h2>
      <ul>
        <% @user.errors.full_messages.each do |msg| %>
          <li><%= msg %></li>
        <% end %>
      </ul>
    </div>
  <% end %>
  
  # 表单字段和提交按钮等代码
<% end %>