btrc-hub/backend/app/models/wiki_asset.rb

class WikiAsset < ApplicationRecord
  belongs_to :wiki_page
  belongs_to :created_by_user, class_name: 'User'

  has_one_attached :file

  validates :file, presence: true

  def url
    Rails.application.routes.url_helpers.rails_blob_url(file, only_path: true)
  end
end