How to get validated entity attributes?

[matteofortier]

Following the common design/access pattern of using a transaction to maintain uniqueness on multiple attributes, I wanted to know how I would be able to get an entity object post validation by electroDB.

To elaborate: I have a user entity, with required default attributes such as userId, createdAt and updatedAt, all defined using Entity in electroDB. The user entity also has email and username required attributes, which I want to maintain uniqueness on.

This means when I create a user entity, I must conduct a write transaction that creates the user item, the username item, and the email item. I would like to know how I can obtain those default attribute values such as the generated userId. I understand that DynamoDB Transactions do not return those values, but surely there is a way to obtain those values from electroDB before it is executed by the ddb document client so that I can use those values iff the transaction succeeds? Or perhaps there is a way to validate my object with the electroDB entity?

I understand there is the .param() execution but that returns everything including any hidden attributes or keys.

Any insight or solution would be greatly appreciated.