Rails 5 + Shrine + Polymorphic model + Pretty Location - ruby-on-rails

Question

I'm using Shrine for direct uploads to S3 and I'm trying to user the pretty_location plugin to set the location in my S3 bucket.
I have a document model has the file_datatext attribute and is connected to a FileUploader:
class Document < ApplicationRecord
belongs_to :documentable, polymorphic: true
include FileUploader[:file]
validates :file, presence: true
end
Other models are associated with the document model through the following concern:
module Documentable
extend ActiveSupport::Concern
included do
has_one :document, as: :documentable, dependent: :destroy
accepts_nested_attributes_for :document, allow_destroy: true
end
end
This is my FileUploader:
class FileUploader < Shrine
Attacher.promote { |data| PromoteJob.perform_later(data) }
Attacher.delete { |data| DeleteJob.perform_later(data) }
plugin :upload_options, cache: {acl: "public-read"}
plugin :upload_options, store: {acl: "public-read"}
plugin :logging, logger: Rails.logger
plugin :pretty_location
plugin :processing
plugin :delete_promoted
plugin :recache
plugin :restore_cached_data
plugin :delete_raw
plugin :validation_helpers
def generate_location(io, context = {})
# do something depending on context[:record].documentable
end
end
When uploading files from the user's filesystem via the client browser through nested attributes all works as expected and I'm able to generate a pretty location in my S3 bucket.
However, I have another model where I am trying to upload to S3 a PDF file which is generated in the backend with the following setup.
class Invoice < ApplicationRecord
has_one :documents, as: :documentable, dependent: :destroy
end
The Invoice model doesn't use the concern as I want it to connect to the polymorphic document with a has_many association.
class Api::V1::InvoicesController < Api::V1::BaseController
def upload_pdf
pdf = InvoicePdf.new(#invoice)
attachment = pdf.render
file = StringIO.new(attachment)
file.class.class_eval { attr_accessor :original_filename, :content_type }
file.original_filename = "invoice_#{#invoice.reference}.pdf"
file.content_type = "application/pdf"
#document = #invoice.documents.new(file: file)
if #document.save
render "documents/show.json", status: :created
else
render json: { errors: #document.errors }, status: :unprocessable_entity
end
end
end
The upload works fine and I am able to upload the PDF to my S3 bucket, but I am not able to generate a pretty location because when I'm inside the generate_location method the context[:record] both the documentable_type and the documentable_id are nil.
This is a strange behaviour as in the rails console I am able to see that the association is correctly set after the upload has been done (without pretty_location) by running Invoice.last.documents.file.url.
I have tried creating the document record in different ways, have tried using the same documentable concern that works for other models but the result is alway the same and I have run out of ideas.
Does anyone have a clue why the documentable_type and documentable_id are not being passed into the context object inside the FileUploader?

Answer 1

The above setup actually works. I was using a breakpoint inside the generate_location FileUploader method and the api was breaking because that method was returning nil.
After fixing that, the first time it ran documentable was still nil but the method would run a second time with the documentable attributes present.
def generate_location(io, context = {})
return "" unless context[:record].documentable
path = if context[:record].documentable_type == "SomeClass"
# do something
elsif context[:record].documentable_type == "OtherClass"
# do something else
else
# do something else
end
return path
end