Rails 3,Paperclip - 自定义插值

Question

我一直在制作定制插值的麻烦,经历了我在网上找到的每一个例子,但不管我做了什么,都没有成功.目前我有这个:

模型

has_attached_file :photo,
  :path => ":rails_root/public/images/:img_name-:style.:extension",
  :styles => {
    :original => '100x100',
    :thumb => '30x30'
}

初始化/ paperclip.rb

Paperclip.interpolates :img_name do |attachment, style|
  attachment.instance.img_name
end

img_name在上传时使用图像填充表单.我上传的错误是:

参数无效 - (C:/ Users /.../ stream20110410-384-stl2lk20110230-213-1fm2bab,C:/.../ photo_upload/public/images /:img_name-original.jpg)

Answer 1

如果它直接在模型中似乎工作:

class Model < ActiveRecord::Base

  Paperclip.interpolates :img_name do |attachment, style|
    attachment.instance.img_name
  end

  has_attached_file :photo,
    :path => ":rails_root/public/images/:img_name-:style.:extension",
    :styles => {
      :original => '100x100',
      :thumb => '30x30'
    }

end