On Dec 13, 2006, at 1:20 PM, Zak Burke wrote:
> 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.
Then allow me to confuse you. :-P I have a large project with the
PK exposed all over the place. Bad or good, that is the way it is.
It does not cause problems. Only exposing the FK seems to cause this
problem. I do agree that having a validation for this in Entity
Modeler is probably a good thing.
Chuck
--Practical WebObjects - for developers who want to increase their overall knowledge of WebObjects or who are trying to solve specific problems. http://www.global-village.net/products/practical_webobjects
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