Grape Attachment Route

grape_remedy_route.rb

params do
  requires :id, type: String
  requires :work_log_id, type: String
  requires :attachment_field, type: String
end
get ":id/work_log/:work_log_id/:attachment_field" do
  find_elixir_object
  authorize! permission_key(:read, @elixir_object), @elixir_object
  error!({ error: "No Work Log Entry for \#{params[:id]} with ID \#{params[:work_log_id]}"}, 404) if @elixir_object.work_log_entries.blank?
  key = @elixir_object.work_log_entries.first.class.elixir_primary_key
  work_log_entry = @elixir_object.work_log_entries.select{|w| w[key.to_sym]==params[:work_log_id]}
  if work_log_entry.blank?
    error!({ error: "No Work Log Entry for \#{params[:id]} with ID \#{params[:work_log_id]}"}, 404)
  else
    content_type "application/octet-stream"
    env['api.format'] = :binary
    attachment = work_log_entry.first[params[:attachment_field].to_sym]
    error!({ error: "No Work Log Attachment \#{params[:attachment_field]} for \#{params[:work_log_id]} on \#{params[:id]}"}, 404) unless attachment
    filename = File.split(attachment.name).last
    header['Content-Disposition'] = "attachment; filename=\#{filename}"
    ## This calls 	getEntryBlob(String formName, String entryID, int fieldID, String filePath)
    work_log_entry.first.get_blob(params[:attachment_field].to_sym, Rails.root.join("tmp/\#{filename}").to_s)
    ## Would prefer to call getEntryBlob(String formName, String entryID, int fieldID) and return the bytes directly.
    File.binread(Rails.root.join("tmp/\#{filename}"))
  end
end