Rails: form_for中的隐藏字段不向控制器发送参数

Question

我在我的视图帮助器中创建了一个form_for，它将允许一个用户从一个组中提升另一个用户。

  def promote_button_for(group, user)
    membership = group.get_membership( user )
    form_for membership, :url => group_membership_path( group, membership ) do |f|
      f.hidden_field :group_creator
      hidden_field_tag 'test', '1'
      f.submit( "Promote", :onclick => "return confirm(\"Are you sure you want to promote #{user.email} to an officer?\")" )
    end
  end

当我通过按钮提交表单时，我似乎没有得到任何发送到控制器的隐藏字段参数。

Started POST "/groups/1/memberships/6" for 127.0.0.1 at 2011-02-01 01:45:32 -0600
  Processing by MembershipsController#update as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"VQl/rVX8OVOETv2HE7KtopUc3B19ShoMkUhjJwNlaZs=", "commit"=>"Promote", "group_id"=>"1", "id"=>"6"}

生成的Html如下所示：

<form accept-charset="UTF-8" action="/groups/1/memberships/6" class="edit_membership" id="edit_membership_6" method="post">
   <div style="margin:0;padding:0;display:inline">
      <input name="utf8" type="hidden" value="&#x2713;" />
      <input name="_method" type="hidden" value="put" />
      <input name="authenticity_token" type="hidden" value="VQl/rVX8OVOETv2HE7KtopUc3B19ShoMkUhjJwNlaZs=" />
   </div>
   <input id="membership_submit" name="commit" onclick="return confirm(&quot;Are you sure you want to promote kquiring@gmail.com to an officer?&quot;)" type="submit" value="Promote" />
</form>

任何帮助都将不胜感激，

谢谢!

Answer 1

之所以会出现这个问题，是因为form_for对象只看到由最后一个f.submit标记生成的字符串，而form_for和f.submit之间的其他所有内容都丢失了。

在本例中，form_for标记并不直接操作视图，因为它基本上只是一个从promote_button_for方法返回的字符串。

答案是，您只需要将生成的标记链接在一起，如下所示：

def promote_button_for(group, user)
  membership = group.get_membership( user )
  form_for membership, :url => group_membership_path( group, membership ) do |f|
    f.hidden_field(:group_creator) << \
    hidden_field_tag('test', '1') << \
    f.submit( "Promote", :onclick => "return confirm(\"Are you sure you want to promote #{user.email} to an officer?\")" )
  end
end

请注意<< \，它将所有生成的字符串连接在一起并将它们返回给form_for。

Answer 2

你能试一下吗？

f.hidden_field :group_creator, {:value => ''}