11 May
2007
11 May
'07
8:33 a.m.
On Thu, 2007-05-10 at 16:42 +0200, Lukas Renggli wrote:
How do you model a reference between objects? I think it is quite
common to interconnect objects ;)
Well, the MARelationDescriptions were ment for that. They work well
for some cases I encountered in industrial applications and to
describe Magritte in itself, however they fail to describe relations
in general.
One of the problems is that you have a description on every end of
the relation. Sometimes they are the same, sometimes not. Mostly the
framework assumes that this is a MAContainerDescription, but
sometimes it is not. When validating the framework has to decide
which one to use and if it should recurse the validation into the
referenced description.
What I would prefer is to have a multiplicity for all the
descriptions. It would probably make the form generation more
difficult, but it would cleanly solve the above problems.
Yes please.
Could you please provide some experience about your modeling with
Magritte? If you use automatic form generation you need to model
relationships, right? How do you model cases where objects reference
each other?
Norbert
How can it
happen that that condition gets the real object as a
value
instead of the memento? In the failure case I do not invoke self
value: at all. So I'm sure not to store anything strange.
I personally never used the MAToOneRelationDescription and
MAToManyRelationDescription. The design of how Magritte handles those
is simply wrong, therefor many people run into problems when using
them. I suggest
that somebody that really needs them gives a try and
implements them cleanly. I have some ideas about that, but
unfortunately I don't have the time to do it myself.
Me neither. Maybe I have to do it soon because I use references
a lot and I don't think I can rip them out now.