回形针自定义路径，id 为 belongs_to

Question

我在一个项目中使用回形针。

相关模型如下所示：

class Asset < ActiveRecord::Base

  has_paper_trail                              # Track model with paper_trail
  has_attached_file :image, :styles => { :medium => "300x300>"}, 
  :path => ":rails_root/public/attachments/project_#{:project_id}/ressources/:basename_:style.:extension"

  belongs_to :project

end

如您所见，我想在我的图像路径中包含相关项目的 id，我该怎么做？

Answer 1

试试这个

has_attached_file :image, :styles => { :medium => "300x300>"}, 
 path => ":rails_root/public/attachments/:project_id/ressources/:basename_:style.:extension"

然后写

Paperclip.interpolates :project_id do |attachment, style|
    "project_#{attachment.instance.project_id}"
  end