David Avendasora wrote:
Hi.
I have a relationship from Label to Part (toOne)
Part has three subclasses: Raw, Intermediate and Finished. All of
these (Part, Raw, Intermediate and Finished) are all EOGenericRecord
classes right now.
I'm running into two problems
1) How do I perform an instanceof to determine what subclass of Part
takeStoredValueForKey("part") returns when run on a Label object? Do I
have to generate the custom classes first for Part and it's subclasses?
2) How do I call subclass-specific methods with key value-coding when
the relationship is to the superclass? I have no problem executing
superclass-specific methods using
valueForKeyPath("part.partDescription"), but I want something along
the lines of valueForKeyPath("finished.unitQuantity") (unitQuantity is
an attribute of the Finished subclass of Part)
Well, instanceof in an OO design is generally considered bad practice.
You may want to reconsider if your design requires it. If you really do
need to know what something is I think you can do something like getting
the EODescription/EOClassDescription of the EOGenericRecord and one of
the attributes is the name you've given it.
What's the problem you're running into with the second thing? If you
have a relationship to something and you do what you've written it
should just work.
-arturo
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