Support unpacking/packing of props

[birnbuazn]

We often have the situation, where a more complex domain model must be mapped to an api with a flat request/response model.

For example:

data class Car(
  val engine: Engine
  val numberOfWheels: Int
)

data class Engine(
  val horsePower: Int
)

should be mapped to

data class CarResponse(
  val horsePower: Int
  val numberOfWheels: Int
)

I didn't find an easy way to tell Mappie, that I want all properties of the child (Engine) mapped to the response (CarResponse) .

It might be easy/obvious in this case to just map this single property, but things get a little unwieldy, if there are a lot of child properties involved.

Same is true the other way round as well. Imagine a flat request model, which has to be mapped to a more structured domain model.

[stefankoppier]

Hi @birnbuazn. Thanks for the suggestion. I agree that it is a good addition, as this is a common use-case.

However, I don't have a lot of spare time at the moment, and my current focus is on #198, which requires a fairly big refactoring. If you feel up to it, you're more than welcome to contribute. I could point you in the right direction how this can be done.