一个TextField，用于DataTransformer的两个属性

I have searched a lot on google but I have no idea of how to solve my problem. I have an Entity EntreeListe which contains two attributes rayon and produit. I would like that the user enter in a text field : Rayon : Produit.

So, I add two DataTransformer on my textfield produit

$builder->get('produit')
    ->addModelTransformer(new StringToProduitTransformer($this->manager));
$builder->get('produit')
    ->addModelTransformer(new StringToRayonTransformer($this->manager));

So that I can transform explode(' : ', $string)[0] into a Rayon and explode(' : ', $string)[1] into a Produit.

The problem is that, when I submit the form, the parameter passed to reverseTransform of StringToProduitTransformer is not a string but a Rayon because the transformation of StringToRayonTransformer is already done.

I don't know if I'm clear, so just ask questions. Any suggestions is welcome :).

What I want is to have the string passed to the two reverseTransform... So have multiple DataTransformer for one field.

Or is there another way to do this ? To complete two attributes with one input ?

Thank you very much.