Rubyonrails 如何根据当前 Rails 环境设置回形针的存储机制

在玩了一段时间后，我想出了一个模块，可以满足我的需求.

app/models/shared/attachment_helper.rb以内:

module Shared
  module AttachmentHelper

    def self.included(base)
      base.extend ClassMethods
    end

    module ClassMethods
      def has_attachment(name, options = {})

        # generates a string containing the singular model name and the pluralized attachment name.
        # Examples: "user_avatars" or "asset_uploads" or "message_previews"
        attachment_owner    = self.table_name.singularize
        attachment_folder   = "#{attachment_owner}_#{name.to_s.pluralize}"

        # we want to create a path for the upload that looks like:
        # message_previews/00/11/22/001122deadbeef/thumbnail.png
        attachment_path     = "#{attachment_folder}/:uuid_partition/:uuid/:style.:extension"

        if Rails.env.production?
          options[:path]            ||= attachment_path
          options[:storage]         ||= :s3
          options[:url]             ||= ':s3_authenticated_url'
          options[:s3_credentials]  ||= File.join(Rails.root, 'config', 's3.yml')
          options[:s3_permissions]  ||= 'private'
          options[:s3_protocol]     ||= 'https'
        else
          # For local Dev/Test envs, use the default filesystem, but separate the environments
          # into different folders, so you can delete test files without breaking dev files.
          options[:path]  ||= ":rails_root/public/system/attachments/#{Rails.env}/#{attachment_path}"
          options[:url]   ||= "/system/attachments/#{Rails.env}/#{attachment_path}"
        end

        # pass things off to paperclip.
        has_attached_file name, options
      end
    end
  end
end

(Note: I'm using some custom paperclip interpolations above, like 100, 101 and 102. You'll need to modify things as needed for your particular application)

现在，对于每个有回形针附件的模型，你只需要包含这个共享模块，并调用has_attachment方法(而不是回形针的has_attached_file)

示例模型文件:app/models/user.rb:

class User < ActiveRecord::Base
  include Shared::AttachmentHelper  
  has_attachment :avatar, :styles => { :thumbnail => "100x100>" }
end

有了这个选项，根据您的环境，您可以将文件保存到以下位置:

Development:

RAILS_ROOT + public/attachments/development/user_avatars/aa/bb/cc/aabbccddeeff/thumbnail.jpg

Test:

RAILS_ROOT + public/attachments/test/user_avatars/aa/bb/cc/aabbccddeeff/thumbnail.jpg

Production:

https://s3.amazonaws.com/your-bucket-name/user_avatars/aa/bb/cc/aabbccddeeff/thumbnail.jpg

这正是我想要的，希望它对其他人也有用.:)

-约翰