Re: EO model validation with Wonder and foreign keys

Zak Burke wrote on 12/12/06 7:32 PM:
> I thought I would bite the bullet and install Wonder, to see if it made 
> all my EO Model/Entity Modeler validation issues magically disappear. 
> I've written about this problem before but was never able to resolve it. 
> Here it is, in a nutshell: When an EO has a required relation, Entity 
> Modeler complains if the EO's foreign key is not also marked as 
> required. EOF, however, chokes when the foreign key is required because 
> it handles validation before a new related object has been persisted, 
> and therefore has no foreign key to assign.

Well, I managed to solve this.

The problem only appears if the relationship's foreign key is accessible 
as a class property. If the foreign key is not a class property, then 
apparently EOF never gets access to the property to notice that fact 
that it's empty. That kinda makes sense, but in an ostrich-like way. (If 
I don't look for a value that isn't allowed to be empty, it must not be 
empty! Hooray!)

I understand how my model caused this to occur, but it seems like the 
model should throw an error whenever a property used as part of a 
relationship is exposed as a class property.

I know some modeling wonks will flame me about how PKs and FKs shouldn't 
be exposed anyhow and I could have avoided all these problems if I had 
just followed recommendations about what fields to expose. IMNSHO, the 
recommendation ought to be a rule because violating it causes an error. 
At the very least the documentation should explain the consequences of 
ignoring it.

Ah well; at least now I understand.

zak.