How to serialize a has_many_attached in Active Model Serializer using JSON API format?

Question

As of right now, i have a model with a has_one_attached :file which i'm serializing with a method as follows.

# app/models/my_model.rb
class MyModel < ApplicationRecord
  has_one_attached :file

  def file_url
    if file.attached?
      Rails.application.routes.url_helpers.rails_blob_url(file)
    end
  end
end

And then in my serializer with activemodel serializer( JSON API format)

type :my_model

attributes(
  :file_url
)

Which works just fine, now i'm moving to a has_many_attached :files, and i'm having problems serializing it. i've tried:

class MyModel < ApplicationRecord
  has_many_attached :files
  
  def files_url
    files.each_With_object([]) do |file, array|
    array << Rails.application.routes.url_helpers.rails_blob_url(file)
  end
end

then in my app/controller/my_model_controller.rb

  def my_model_params
    params.require(:my_model).permit(:files => [])
  end

And finally, in my serializer, i just call :files_url(instead of file_url, as i used to, which worked with one file), but it won't work:

type :my_model

attributes(
  :files_url
)

Any idea on what am i missing? I can't seem to find much useful info regarding serializing has_many_attached. Thanks

Answer 1

Fixed it! it actually works, i was just sending the wrong params to Insomnia.

I replaced :files => [] in my_model_params with files: []. And in Insomnia i send each file in the my_model[files][] param.