rails paperclip自定义上传网址路径

Question

This is my upload.rb

class Upload < ActiveRecord::Base
      belongs_to :post
      has_attached_file :upload,styles: { medium: ["500x400>",:jpg], thumb: ["100x100>",:jpg]},url: "/post_images/post_:postid/:style/:filename"

def postid
      self.post_id
end
end

I have a column with post_id. As belongs_to represents i will have more than one images for one post. But while saving files in folder instead of post_25 . It is storing as post_:postid

But if i give as :id it is working.

How can i solve it. can anyone help with this.

Answer 1

You should be using Paperclip's interpolations to achieve this functionality. First, start by defining an interpolation in an initializer:

# config/initializers/interpolations.rb
Paperclip.interpolates :postid do |attachment, style|
  'post_' + attachment.instance.post.id
end

Then, you can use the :postid interpolation directly in your attachment URL declaration (remember to restart your server first):

# app/models/upload.rb
has_attached_file :upload,styles: { medium: ["500x400>",:jpg], thumb: ["100x100>",:jpg]},url: "/post_images/:postid/:style/:filename"

Note that :postid is not merely the instance method you've defined in your model – Paperclip exclusively utilizes interpolations to define dynamic variables within URL/path declarations.

Answer 2

In one of my models I have

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

which was taken from Paperclip wiki on Github.