Declaring node with pydantic

[0xelight]

First of all thank you for your work with this useful package.
Were you familiar with the pydantic package? but using this package to declare a node class with neomodel would be huge.
Check https://docs.pydantic.dev/
Especially with validator fields, using python/annotated typing, openapi export, fastapi integration...

What do you think about that?

[aanastasiou]

Hi @0xelight

neomodel handles its own validation, through node/relationship properties to ensure that the constraints of the data model it describes are enforced. (For example, see here and here).

I have not looked into the openapi, fastapi specifications in detail, but we can probably create mappings between the neomodel conventions and a given convention if the same entities would have to be used across systems. The validation rules should match but it is always a good idea to validate at the interface to another system.

It has been proposed as a feature for a future release, to at least start adding type hints (as in, plain simple Python type hints), to every interface in the API.

[mariusconjeaud]

That would be interesting to look at indeed !

From my perspective of neomodel as a user, I've always used it inside of an API, with FastAPI as a framework, which indeed includes pydantic and it's very helpful there (to validate what comes in/out of the API).

Maybe the upside of having neomodel run its own validation though is that we can more easily map the allowed types and validations with the Neo4j allowed types, not sure if we can extend pydantic to do that ?

[hardchor]

I think it should be possible to implement base nodes and relationships (e.g. how neontology does it: https://github.com/ontolocy/neontology/blob/main/src/neontology/basenode.py), but definitely not a small change.