Rails - 使用CarrierWave和Cocoon编辑附件

我有两个型号， Evidence 和 Attachment . 证据有很多附件，我使用CarrierWave来处理附件上传 .

我可以轻松地创建具有多个附件的证据，但是一旦创建了证据，我似乎无法添加其他附件 . 表单工作正常，但附件不保存 .

这是我的代码的基本设置：

（APP /模型/ evidence.rb）

class Evidence < ActiveRecord::Base
  has_many :attachments, as: :attachable
  accepts_nested_attributes_for :attachments, allow_destroy: true
end

（APP /模型/ attachment.rb）

require 'digest'

class Attachment < ActiveRecord::Base
  mount_uploader :attachment, AttachmentUploader
  belongs_to :attachable, polymorphic: true
  attr_accessor :override_filename
  delegate :file, to: :attachment

  after_create do
    AttachmentFilesizeJob.perform_later(self)
    AttachmentMd5sumJob.perform_later(self)
  end
end

（应用程序/视图/证据/ _form.html.erb）

<%= simple_form_for(@evidence) do |f| %>
  <%= f.error_notification %>

  <div class="panel panel-default">
    <div class="panel-heading">
      <h3 class="panel-title">Attachments</h3>
    </div>
    <div class="panel-body">

      <table class="table table-condensed table-striped">
        <thead>
          <tr>
            <th>File</th>
            <th colspan="1"></th>
          </tr>
        </thead>
        <tbody id="attachments_table">
          <%= f.fields_for :attachments do |af| %>
            <% if af.object.attachment.nil? %>
              <%= render 'attachment_fields', f: af %>
            <% else %>
              <tr>
                <td><code><%= af.object.attachment %></code><%= attachment_download_button(af.object) %></td>
              </tr>
            <% end %>          
          <% end %>
        </tbody>
      </table>

      <div id="links">
        <%=
          link_to_add_association 'Add Attachment', f, :attachments,
            :"data-association-insertion-node" => 'tbody#attachments_table',
            :"data-association-insertion-method" => 'append',
            class: 'btn btn-primary btn-sm'
          %>
      </div>
    </div>
  </div>  

  <div class="form-actions">
    <%= f.button :submit %>
  </div>
<% end %>

（应用程序/视图/证据/ _attachment_fields.html.erb）

<tr class="nested-fields form-inline form-table-row">
  <td>
    <%= f.file_field :attachment %>
  </td>
</tr>

我该怎么做才能为已经创建的证据添加附件？创建新证据时一切正常，但编辑时却没有 .

证据上的参数#create（带有两个附件 - strain1.csv和strain2.csv）

参数：{“utf8”=>“✓”，“authenticity_token”=>“rKq1zaDAc1w1GlgF8Q ejjVuA6YXYc5EfhCwHXltK / 4vijOJw1ffeHUY3GWSSmKLevbfxBSwMAeEIjuHw4BIhQ ==”，“evidence”=> {“source”=>“”，“notes”=>“”，“ mutation_id“=>”“，”attachments_attributes“=> {”1476226326082“=> {”attachment“=>＃，@ original_filename =”strain1.csv“，@ content_type =”text / csv“，@ headers =”Content-“处理：form-data; name = \“evidence [attachments_attributes] [1476226326082] [attachment] \”; filename = \“strain1.csv \”\ r \ nConContent-Type：text / csv \ r \ n“>}， “1476226412102”=> {“attachment”=>＃，@ original_filename =“strain2.csv”，@ content_type =“text / csv”，@ headers =“Content-Disposition：form-data; name = \”evidence [attachments_attributes ] [1476226412102] [attachment] \“; filename = \”strain2.csv \“\ r \ nConContent-Type：text / csv \ r \ n”>}}}，“commit”=>“创建证据”}

这两个附件保存得很好 . 然后我尝试编辑证据并添加一个额外的附件，“strain3.csv” - 这里是证据#date更新的参数：

参数：{“utf8”=>“✓”，“authenticity_token”=>“QsYgeVnsTf8oegVaJ733JD93MPxnH1aXutC9dDDAf53B5qY9Onvh22h4gTpE AshcO / snmTOqNRA4jbuii0c5g ==”，“evidence”=> {“source”=>“”，“notes”=>“”，“ mutation_id“=>”“，”attachments_attributes“=> {”0“=> {”id“=>”87“}，”1“=> {”id“=>”88“}，”1476226681765“=> {“attachment”=>＃，@ original_filename =“strain3.csv”，@ content_type =“text / csv”，@ headers =“Content-Disposition：form-data; name = \”evidence [attachments_attributes] [1476226681765] [附件] \“; filename = \”strain3.csv \“\ r \ nConContent-Type：text / csv \ r \ n”>}}}，“commit”=>“更新证据”，“id”=>“ 1" }

第三个附件永远不会上传或保存 .