向rails表单帮助器添加html属性

我正在自定义默认设置，在会话视图中设计new.html.erb，以便生成如下html代码

  <form class="form-signin" role="form">
    <h2 class="form-signin-heading">Please sign in</h2>
    <input type="text" class="form-control" placeholder="Email address" required autofocus>
    <input type="password" class="form-control" placeholder="Password" required>
    <label class="checkbox">
      <input type="checkbox" value="remember-me"> Remember me
    </label>
    <button class="btn btn-lg btn-primary btn-block" type="submit">Sign in</button>
  </form>

我不确定下一步要修改什么

<div><%= f.label :email %><br />
  <%= f.email_field :email  %></div>

所以它生成了：

?？？ 谢谢大家!

<%= f.text_field :email, placeholder: "Email address",
required: true, autofocus: true  %>

应该有用

<%= f.text_field :email, placeholder: "Email address",
required: true, autofocus: true  %>