troessner / has_uuid Goto Github PK

@exviva

Right now we are using two callbacks unconditionally to generate the uuid: 6fb3387#L1R23

Back then I was ok with it, however, thinking about it now I am not so sure that we should do this anymore.

Why did we add it in the first place?

Well, apparently there is no AR callback that gets triggered before the before_validation even if we do not validate the object.
So there could (and has in our applications) arise the following cases:

a) Say we only use "before_validation"

• We have a model which has a "validates_presence_of :uuid"
• We sometimes need to save a model without validations
• In this case, the model is saved but no UUID is generated

b) We only use "before_save"

• In this case we can not use "validates_presence_of :uuid" because the validations would crash before

So, as kind of a workaround we just added both callbacks.

I think this isn't good for one reason:

Inefficiency. We're talking about adding and executing one more callback than actually necessary.

A better solution:

I think we should remove the "before_save" callback and make it prominent in the documentation: "If you do NOT validate an object, you need to manually call assign_uuid". Also, we would have to adjust our code that uses it (right now I can only think of one, possibly two places in the nucleus).

What do you think?