我的嵌套模型形式在第一层次上工作很好.但是我的印象是,你可以使用acceptance_nested_attributes_for深入许多层次.但是当我尝试下面的代码时,“
Image”属性被附加到顶层的“问题”模型,并且在使用未知属性“Image”错误的表单提交时中断.
我可以使用表单数据手工完成所有的插入,但如果Rails可以自动处理,那么明显的原因会更好.
我究竟做错了什么？我试过改变| af |在“图像做的领域”到它自己的唯一名称,但没有任何影响.
楷模：
class Question < ActiveRecord::Base has_one :answer accepts_nested_attributes_for :answer end class Answer < ActiveRecord::Base belongs_to :question has_one :image accepts_nested_attributes_for :image end class Image < ActiveRecord::Base belongs_to :answer end
控制器：
def new
@question = Question.new
answer = @question.build_answer
image = answer.build_image
@case_id = params[:id]
render :layout => 'application',:template => '/questions/form'
end
def create
question_data = params[:question]
@question = Question.new(question_data)
if @question.save
...
end
视图：
= form_for @question,:html => {:multipart => true} do |f|
= f.label :text,"Question Text:"
= f.text_area :text,:rows => 7
%br
%br
=f.fields_for :answer,do |af|
= af.label :body,"Answer Text:"
= af.text_area :body,:rows => 7
%br
%br
= f.fields_for :image do |af|
= af.label :title,"Image Title:"
= af.text_field :title
%br
= af.label :file,"Image File:"
= af.file_field :file
%br
= af.label :caption,"Image Caption:"
= af.text_area :caption,:rows => 7
= hidden_field_tag("case_id",value = @case_id)
= f.submit
解决方法
我认为你的表单变量稍有混淆.它应该是：
= form_for @question,:rows => 7
%br
%br
= af.fields_for :image do |img_form|
= img_form.label :title,"Image Title:"
= img_form.text_field :title
%br
= img_form.label :file,"Image File:"
= img_form.file_field :file
%br
= img_form.label :caption,"Image Caption:"
= img_form.text_area :caption,value = @case_id)
= f.submit
注意form_for … do | f |产生f.fields_for … do | af |,这反过来产生af.fields_for … do | img_form |.
关键是第二个字段.应该是af.fields_for：image do | img_form |而不是f.fields_for：image do | img_form |.