Paperclip::Attachment - undefined method `attach'. Asset Migration Rake Task

Question

I am currently migrating from Paperclip to Active Storage using this tutorial, as well as referencing the official guide .

Current roadblock is the rake task for migrating my assets .

This is the content of my lib/tasks/migrate_paperclip_assets.rake file:

desc 'Generates file names on AWS S3 and places them in their proper structure'
namespace :posts do
  task migrate_to_active_storage: :environment do
    Post.where.not(image_file_name: nil).find_each do |post|
      img_filename = post.image_file_name
      ext = File.extname(img_filename)

      image_url =
      "https://#{Rails.application.credentials.dig(:aws,
      :bucket_name)}/#{Rails.application.credentials.dig(:aws,
      :host_name)}/posts/images/000/000/#{post.id}/original/#{img_filename}"
      puts image_url
      post.image.attach(io: open(image_url),
                            filename: post.image_file_name,
                            content_type: post.image_content_type)
    end
  end
end

When I run this, I get the following error:

rake aborted!
NoMethodError: undefined method `attach' for #<Paperclip::Attachment:0x00000003170090> 
[...]

On the Rails migration guide, it clearly states to use this method attach here in the same format as I have done - not sure why this spews an error. I know for sure that the url works and I have successfully attempted to download the images.

Here are things I have tried that did not work:

1. Attempted this accepted solution .
2. The closest thing to attach I saw from the docs was assign method. But there were no handlers for dealing with the image file.
3. I also have tried downloading the files in the same directory and uploading them using the same post.image.attach .

Even though the Paperclip Attachment Class itself does not have an attach method defined, there are a good number of repos on GitHub with code having similar format: user.avatar.attach(io: open(avatar_url), filename: user.avatar_file_name) .

This is the content of my app/models/post.rb file:

class Post < ApplicationRecord
    belongs_to :user
    has_many :comments, dependent: :destroy
    has_many :likes, dependent: :destroy
    has_many :dislikes, dependent: :destroy
    attr_accessor :uploaded_image_for_io_adapters, :file_name, :top_text, :bot_text


    has_attached_file :image  

  validates_attachment_content_type :image, content_type: /\Aimage\/.*\z/
  validates_attachment :image, presence: true
  validates_presence_of :poster
    validates_presence_of :description
    validates :user, presence: true
    validates :user_id, presence: true
end

Lost and confused, if you could suggest an alternative to bypass having to use this attach method, or give me pointers as to what it is I might be doing wrong that would be great.

For context, Ruby version: 2.4.1, Rails: 5.2.1

Answer 1

I think that the solution is in the documentation you have shared .

class Organization < ApplicationRecord
  # New ActiveStorage declaration
  has_one_attached :logo

  # Old Paperclip config
  # must be removed BEFORE to running the rake task so that
  # all of the new ActiveStorage goodness can be used when
  # calling organization.logo
  has_attached_file :logo,
                    path: "/organizations/:id/:basename_:style.:extension",
                    default_url: "https://s3.amazonaws.com/xxxxx/organizations/missing_:style.jpg",
                    default_style: :normal,
                    styles: { thumb: "64x64#", normal: "400x400>" },
                    convert_options: { thumb: "-quality 100 -strip", normal: "-quality 75 -strip" }
end

It looks like the has_attached_file has to be replaced by has_one_attached .

Otherwise, image will use Paperclip instead of ActiveStorage (which has attach method).