Ruby on rails 多个具有多个多态关系返回错误

我认为“服务”和“形象”模型之间存在多态关系。将有多个模型与图像模型相关，但目前只有一个，所以这就是为什么“图像”模型是多态的。我还有4种不同的图像类型，所以我在“服务”模型中添加了4种有很多关系的图像。“服务”模型还添加了

“接受：图像的嵌套属性”

因此，在_forms.html.erb中，我为FormHelper提供了两个不同的

字段，每个字段都有不同的来源。但是每当我尝试创建一个新的时，我得到了
“nil:NilClass的未定义方法[]”
错误

以下是服务和图像模型：

class Service < ActiveRecord::Base
    has_many :images, as: :imageable, :dependent => :destroy
    has_many :images_title,-> {where "image_type = 2"}, as: :imageable, class_name: "Image", :dependent => :destroy
    has_many :images_icon,-> {where "image_type = 1"}, as: :imageable, class_name: "Image", :dependent => :destroy
    has_many :images_regular,-> {where "image_type = 3"}, as: :imageable, class_name: "Image", :dependent => :destroy

    accepts_nested_attributes_for :images


end

class Image < ActiveRecord::Base
    belongs_to :imageable, polymorphic: true

    mount_uploader :image, ImageUploader

    enum image_type: {icon: 1, title: 2, regular: 3, slider: 4}

end

_form.html.erb：

<div class="control-group">
   <%= f.simple_fields_for :images_title do |image| %>


     <div class="controls">
        <label class="control-label">Hizmet Büyük Resimi</label> 
        <div class="fileupload fileupload-new" data-provides="fileupload">
          <div class="fileupload-new thumbnail" style="width: 200px; height: 150px;">
            <% if image.object.nil? %>
              <img src="http://www.placehold.it/200x150/EFEFEF/AAAAAA&amp;text=no+image" alt=""/>
            <% else %>
              <%= image_tag image.object.image_url %>
            <% end %>
          </div>
          <div class="fileupload-preview fileupload-exists thumbnail" style="max-width: 200px; max-height: 150px; line-height: 20px;"></div>
          <div>
            <span class="btn btn-file"><span class="fileupload-new">Resim Seç</span><span class="fileupload-exists">Değiştir</span>
              <%= image.input :image, input_html: { type: :file, class: "default"}, wrapper: false, label: false %>
              <%= image.input :image_type, :as => "hidden", :input_html => { :value => :title } %>
            </span>
            <a href="#" class="btn fileupload-exists" data-dismiss="fileupload">Sil</a>
          </div>
        </div>


     </div>
   <% end %>
</div>


Hizmet Büyük Resimi
Resim SeçDeğiştir
“隐藏”，：输入\ html=>{：值=>:title}%>

服务被正确插入，但在嵌套属性中我得到了一个错误。所以我做错了什么吗？
我已经处理过很多多态关系，我已经做了您在这里尝试做的事情：您正在实例化多个“类型”的图像。我在我的博客中展示了如何使用枚举，这与您的图像类型字段是一样的

这篇博文涵盖了从控制器到表单的所有内容。在我的示例中，我将同一记录的四种不同类型实例化为表单中的嵌套属性。这样你就可以完成任务了

简单地说，您将要改变的是，您只需要为您的图像使用一条和多条线路。另一个主要问题是，您需要对通过表单上传的每个图像实例使用构建

<div class="control-group">
   <%= f.simple_fields_for :images_title do |image| %>


     <div class="controls">
        <label class="control-label">Hizmet Büyük Resimi</label> 
        <div class="fileupload fileupload-new" data-provides="fileupload">
          <div class="fileupload-new thumbnail" style="width: 200px; height: 150px;">
            <% if image.object.nil? %>
              <img src="http://www.placehold.it/200x150/EFEFEF/AAAAAA&amp;text=no+image" alt=""/>
            <% else %>
              <%= image_tag image.object.image_url %>
            <% end %>
          </div>
          <div class="fileupload-preview fileupload-exists thumbnail" style="max-width: 200px; max-height: 150px; line-height: 20px;"></div>
          <div>
            <span class="btn btn-file"><span class="fileupload-new">Resim Seç</span><span class="fileupload-exists">Değiştir</span>
              <%= image.input :image, input_html: { type: :file, class: "default"}, wrapper: false, label: false %>
              <%= image.input :image_type, :as => "hidden", :input_html => { :value => :title } %>
            </span>
            <a href="#" class="btn fileupload-exists" data-dismiss="fileupload">Sil</a>
          </div>
        </div>


     </div>
   <% end %>
</div>