app/serializers/pin_binding_serializer.rb
class PinBindingSerializer < ApplicationSerializer
attributes :device_id, :sequence_id, :special_action, :pin_num, :binding_type
def binding_type
object.special_action ? "special" : "standard"
end
# `sequence_id` and `special_action` are mutually exclusive.
def sequence_id
object.special_action ? nil : object.sequence_id
end
end