Support transformation of values without needing format-specific custom methods

[HassanAkbar]

No description provided.

[ronaldtse]

@HassanAkbar can you please elaborate this task? Is the "value proc" for value validation or for processing the input/output values?

[HassanAkbar]

@ronaldtse From what I understand this was for processing the input/output of the values i.e

class Person < Lutaml::Model::Serializable
  attribute :id, :string, value: -> { |id| id.capitalize }
end

p = Person.new({ id: "abc-123" })
puts p.id
#=> "ABC-123"

Now thinking about it I have a question, do we need to support different procs for input and output?

[ronaldtse]

Ah, now I remember. The "value proc" is meant to handle the simple usage of custom methods, where we are simply going to transfer the import/export of values, without needing complex processing of custom methods, which requires the user to handle the different formats.

Maybe it should just be called "value transform"?

We should differentiate the input and output of values at the attribute level. Or should this go into the format-specific level?

Transforming values at the attribute-level

class Person < Lutaml::Model::Serializable
  attribute :id, :string, transform: {
    import: -> { |id| id.capitalize },
    export: -> { |id| id }
  }
end

Transforming values at the format level

class Person < Lutaml::Model::Serializable
  attribute :id, :string
  xml do
    map_element 'Id', to: :id, transform: {
      import: -> { |id| id.capitalize },
      export: -> { |id| id }
    }
  end
end

Question

Which one?

[HassanAkbar]

@ronaldtse I think if we want the user not to handle multiple format, then adding it to the attribute level seems more reasonable.