Ruby on rails 回形针与嵌套属性问题

使用回形针上传文件。我有项目、附件和关联表。我已经拥有了可以上传文件的一切，但是当它进入项目控制器时，它会寻找一个方法

附件文件名

，然而，我相信它应该是

用户文件名

，因为

：用户文件

是附件模型用于

有附件

语句的。以下是生产日志：

Started POST "/projects" for 136.152.181.137 at Mon Mar 28 16:23:28 -0700 2011
  Processing by ProjectsController#create as HTML
  Parameters: {"commit"=>"Create Project", "authenticity_token"=>"xh0Ld2RKyJ6EF9jLNl3D+r1m50lKv389NCIor3H4fag=", "utf8"=>"?~\~S", "project"=>{"name"=>"Upload Test", "icon_id"=>"1", "categories_attributes"=>{"0"=>{"name"=>"Category 1", "_destroy"=>"false"}}, "content"=>"skee", "description"=>"description", "attachments_attributes"=>{"0"=>{"name"=>"name", "user_file"=>#<ActionDispatch::Http::UploadedFile:0x2aaaaf6b0fd8 @tempfile=#<File:/tmp/RackMultipart20110328-18838-4wasuv-0>, @headers="Content-Disposition: form-data; name=\"project[attachments_attributes][0][user_file]\"; filename=\"resized_DSCF0229.JPG\"\r\nContent-Type: image/jpeg\r\n", @original_filename="resized_DSCF0229.JPG", @content_type="image/jpeg">}}}}
Completed   in 6ms

NoMethodError (undefined method `attachment_file_name' for #<Attachment:0x2aaaaf6a0638>):
  app/controllers/projects_controller.rb:48:in `create'
  app/controllers/projects_controller.rb:47:in `create'

---

我认为问题在于附件模型：

class Attachment < ActiveRecord::Base
  has_attached_file :user_file
  validates_attachment_presence :attachment

---

如果这是生产日志，它在开发环境中不会给出同样的错误吗？

def create
    @project = Project.new(params[:project])

    respond_to do |format|
      if @project.save
        format.html { redirect_to(@project, :notice => 'Project was successfully created.') }
        format.xml  { render :xml => @project, :status => :created, :location => @project }
      else
        format.html { render :action => "new" }
        format.xml  { render :xml => @project.errors, :status => :unprocessable_entity }
      end
    end
  end

class Attachment < ActiveRecord::Base
  has_attached_file :user_file
  validates_attachment_presence :attachment

  validates_attachment_presence :user_file