Ruby on rails 回形针&x2B；S3=>；缺少url的一部分

正在开发一个允许使用回形针上传图片的API。一切正常（图片可以保存在S3上），但我无法在JSON中显示正确url的图片

型号：

class Category < ActiveRecord::Base

  has_attached_file :picture,
    styles: { medium: "300x300>", thumb: "100x100>" },
    default_url: ":s3_eu_url"

    ...  some validations and accessors

end

class CategorySerializer < ActiveModel::Serializer
  attributes :id, :title, :picture
end

config.paperclip_defaults = {
  :storage => :s3,
  :s3_region => ENV['AWS_REGION'],
  :url => ':s3_domain_url',
  :s3_host_name => 's3-eu-west-1.amazonaws.com',
  :path => ':class/:attachment/:id_partition/:style/:filename',
  :s3_credentials => {
    :bucket => ENV['S3_BUCKET'],
    :access_key_id => ENV['S3_ACCESS_KEY'],
    :secret_access_key => ENV['S3_SECRET_KEY']
  }
}

if Rails.env.production?
  Paperclip.interpolates(:s3_eu_url) do |att, style|
    "#{att.s3_protocol}://#{att.bucket_name}.s3-eu-west-1.amazonaws.com/#{att.path(style)}"
  end
end

回形针初始值设定项：

class Category < ActiveRecord::Base

  has_attached_file :picture,
    styles: { medium: "300x300>", thumb: "100x100>" },
    default_url: ":s3_eu_url"

    ...  some validations and accessors

end

class CategorySerializer < ActiveModel::Serializer
  attributes :id, :title, :picture
end

config.paperclip_defaults = {
  :storage => :s3,
  :s3_region => ENV['AWS_REGION'],
  :url => ':s3_domain_url',
  :s3_host_name => 's3-eu-west-1.amazonaws.com',
  :path => ':class/:attachment/:id_partition/:style/:filename',
  :s3_credentials => {
    :bucket => ENV['S3_BUCKET'],
    :access_key_id => ENV['S3_ACCESS_KEY'],
    :secret_access_key => ENV['S3_SECRET_KEY']
  }
}

if Rails.env.production?
  Paperclip.interpolates(:s3_eu_url) do |att, style|
    "#{att.s3_protocol}://#{att.bucket_name}.s3-eu-west-1.amazonaws.com/#{att.path(style)}"
  end
end

运行curl来写一篇文章，我得到了（正确的url）：

在my JSON中显示的url:

"http://wetal-assets-bucket.s3-eu-west-1.amazonaws.com/"

图片的路径丢失，我找不到显示它的方法。 即使我创建了一个方法来在序列化程序中重新定义“：picture”，以便返回“object.picture.url”…结果仍然相同

---

有什么建议吗？

如果在rails控制台中调用

category.image.url

，url是正确的吗？它是不正确的……但我不明白为什么以及如何在我尝试在浏览器中访问它时，curl返回正确的url。