Inheritance: support retaining existing attributes and selective overriding

[ronaldtse]

When inheriting a Serializable class, sometimes we want to retain the existing mappings, and add additional attributes.

Maybe we use a xml(keep: true) do syntax (by default true), e.g. {format}(keep: false) do.

Case 1: add attribute and element

class Klin < Lutaml::Model::Serializable
  attribute :manufacturer, :string
  xml do
    map_element "manufacturer", to: :manufacturer
  end
end

class GlassKlin < Klin
  attribute :max_temp, :integer
  xml(keep: true) do
    map_element "max-temp", to: :max_temp
  end
end

Case 2: modify attribute and element

class Klin < Lutaml::Model::Serializable
  attribute :manufacturer, :string
  xml(keep: false) do
    map_element "manufacturer", to: :manufacturer
  end
end

class Manufacturer < Lutaml::Model::Serializable
end

class GlassKlin < Klin
  attribute :manufacturer, Manufacturer
end

Case 3: modify mapping

class Klin < Lutaml::Model::Serializable
  attribute :manufacturer, :string
  xml do
    map_element "manufacturer", to: :manufacturer
  end
end

class GlassKlin < Klin
  xml do
    map_element "make", to: :manufacturer
    remove_map_element "manufacturer" # is this the best way to delete a mapping?
  end
end