Reusing the transformer of the DAO

[gehel]

I have a value object the is composed of a few other VO. When implementing the tranformer for it, I'd like to reuse the transformer that I already have for the composing VO. Not very clear explanation, I agree ...

Let's say I have an entity A that is composed of an entity B and an entity C

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B<----<>A<>---->C

Each of these entities have value objects, let's call them VA, VB and VC. The value object VA is composed of VB and VC

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VB<----<>VA<>---->VC

Transforming VB and VC is already done, so when I write the transform method for VA, I'd like to reuse the other transforms. They are public methods on the DAO so it should be possible, but how should I access an instance of the other DAO from A's DAO ?

Rereading that, it still sounds a bit confused ... but I hope you can understand what I mean ...

Thanks for your answers !

[wouter.zoons]

your first sentence is the one that's most clear

to access a DAO from another DAO just draw a dependency from the first DAO's entity to the second one, then you'll be able to do this in your first DAO:

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First <<Entity>> -----> Second <<Entity>>

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FirstDao.getSecondDao()

[gehel]

Congratulations for understanding what I meant ! And thanks a lot for the answer, I was sure there was an easy way to do it ...
Thanks !

[wciesiel]

I use one more pattern - if there are VOs inheriting from each other (for example. MyEntityDetailedDto inheriting from MyEntitySimpleDto I use utility class DtoPopulator with methods:

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public static MyEnitytySimpleDto populateMyEntitySimpleDto(MyEntity entity, MyEntitySimpleDto toPopulate) {
  // fill simple fields from entity
  return toPopulate;
}

public static MyEntityDetailedDto populateMyEntityDetailedDto(MyEntity entity, MyEntityDetailedDto toPopulate) {
  toPopulate = populateMyEntitySimpleDto(entity, toPopulate);
  // fill detailed fields
}



it's quite usefull