app/serializers/action_serializer.rb

class ActionSerializer < ApplicationSerializer
  class Reference < ApplicationSerializer
    attributes :iri

    def iri
      urls.action_iri_url(object,
                          host: Settings.hostname,
                          port: Ontohub::Application.config.port)
    end
  end

  attributes :iri, :status, :eta

  def iri
    Reference.new(object).iri
  end

  def eta
    object.eta.to_i
  end
end