Question

我正在使用Rails 3和Paperclip使用多态关联将上传的文件附加到多个对象类型。我创建了一个Asset模型和一个继承的Image模型（将添加其他模型，如后面的视频和文档），如下所示：

# app/models/asset.rb
class Asset < ActiveRecord::Base
  # Nothing here yet
end

# app/models/image.rb
class Image < Asset
  belongs_to :assetable, :polymorphic => true
  has_attached_file :file, {
    :styles => {
      :small => { :geometry => '23x23#', :format => 'png' },
      :medium => { :geometry => '100x100#', :format => 'png' } } 
  }.merge(PAPERCLIP_STORAGE_OPTIONS).merge(PAPERCLIP_STORAGE_OPTIONS_ASSET_IMAGE) # Variables sent in environments to direct uploads to filesystem storage in development.rb and S3 in production.rb
  validates_attachment_presence :file
  validates_attachment_size :file, :less_than => 5.megabytes
end

然后我有另一个对象类型Unit，我将多个图像附加到如下：

# app/models/unit.rb
class Unit < ActiveRecord::Base
  # ...

  has_many :images, :as => :assetable, :dependent => :destroy
  accepts_nested_attributes_for :images

end

# app/controllers/units_controller.rb
class UnitsController < ApplicationController
  # ...

  def new
    @unit = current_user.units.new
    # ...
    @unit.images.build
  end

  def create
    @unit = current_user.units.new(params[:unit])
    # ...
    respond_to do |format|
      if @unit.save
        format.html { redirect_to(@unit, :notice => 'Unit creation successful!') }
      else
        format.html { render :action => "new" }
      end
    end
  end

  def show
    @unit = current_user.units.find(params[:id])
    @unit_images = @unit.images
    # ...
  end

  def edit
    @unit = current_user.units.find(params[:id])
    # ...
    @unit.images.build
  end

  def update
    @unit = current_user.units.find(params[:id], :readonly => false)

    respond_to do |format|
      if @unit.update_attributes(params[:unit])
        format.html { redirect_to(@unit, :notice => 'Unit was successfully updated.') }
      else
        format.html { render :action => "edit" }
      end
    end
  end

  def destroy
    @unit = current_user.units.find(params[:id])
    @unit.destroy

    respond_to do |format|
      format.html { redirect_to(units_url) }
    end
  end

end

# app/views/units/_form.html.haml
.field # Display already uploaded images
  = f.fields_for :images do |assets|
    - unless assets.object.new_record?
      = link_to(image_tag(assets.object.file.url(:medium)), assets.object.file.url(:original))
.field # Display field to add new image
  = f.fields_for :images do |assets|
    - if assets.object.new_record?
      = assets.label :images, "Image File"
      = assets.file_field :file, :class => 'uploadify'

使用这些设置，我可以在每次显示表单时一次上传一张图像。

当我尝试集成Uploadify以添加多文件上传/预览时，问题就出现了。我已经满足了所有的Uploadify依赖性，但为了保存与Unit模型相关的图像，我需要以某种方式包含对unit_id的敬意，以便可以正确地进行多态关联。以下是我目前的上传代码：

%script
  $(document).ready(function() {
    $('.uploadify').uploadify({
      uploader        : '/uploadify/uploadify.swf',
      cancelImg       : '/uploadify/cancel.png',
      auto            : true,
      multi           : true,
      script          : '#{units_path}',
      scriptData      : {
        "#{key = Rails.application.config.session_options[:key]}" : "#{cookies[key]}",
        "#{request_forgery_protection_token}" : "#{form_authenticity_token}",
      }
    });   
  });

因此，虽然我可以轻松地使用Paperclip上传，但Uploadify将无法正常工作。任何帮助将非常感激。提前谢谢。

更新

在做了更多研究之后，我将此评论发送到了类似的问题：Rails3, S3, Paperclip Attachment as it's own model?。有关这种情况是否适用的任何想法？是否有一种简单的方法可以从unit.id方法确定/new并将其传递给Uploadify创建的资产？

Answer 1

我们在将表单加载到draft状态（使用状态机）时立即保存模型，解决了一个非常类似的问题。像这样，当您尝试附加要上传的文件时，该模型可用，一旦您提交表格的其余部分，您基本上只是更新模型，将其状态更改为例如published。更新控制器等是一项小工作，但它确实可以解决问题。

Rails 3 Paperclip Uploadify：在保存对象之前保存上载的对象附件

1 个答案: