Domain Validation in a CQRS architecture

Question

Danger ... Danger Dr. Smith... Philosophical post ahead

The purpose of this post is to determine if placing the validation logic outside of my domain entiti

Answer 1

I wrote a blog post on this topic a while back. The premise of the post was that there are different types of validation. I called them Superficial Validation and Domain Based Command Validation.

This simple version is this. Validating things like 'is it a number' or 'email address' are more often than not just superficial. These can be done before the command reaches the domain entities.

However, where the validation is more tied to the domain then it's right place is in the domain. For example, maybe you have some rules about the weight and type of cargo a certain lorry can take. This sounds much more like domain logic.

Then you have the hybrid types. Things like set based validation. These need to happen before the command is issued or injected into the domain (try to avoid that if at all possible - limiting dependencies is a good thing).

Anyway, you can read the full post here: How To Validate Commands in a CQRS Application