Hi,
after some silence - another progress report.
I had some trouble figuring out the best way to deal with this
situation: remember we have the ClinicalDocuments tied to non-
Singletonian Topcomponents - the Banners. The patient screens are
updated when the user chooses another ClinicalDocument (i.e. a
Patient Banner). This Netbeans magic happened through the General
lookup mechanism and worked fine.
The opposite though had also to happen, and this proved way more
tricky to find out.
The problem is this: the patient screens are all Singletons, and are
fed the ClinicalDocument that they need when the user chooses the
accompanying Patient Banner. When the user changes a Patient name, we
want this change to propagate to the Banner, and this is non trivial
because we want no coupling to exist between the Singleton screen
module and the Banner instance. How to do this?
Even the NB list could not give me an answer - what I want is
apparently a little odd. Point in case is that Netbeans is basically
a file-centered framework and not a database-centered one: so all the
nice file-changed whizzbang framework methods were of no use here. I
have seen more people complaining about the lack of facilities that
implies to us database-using types, but that was not much help.
Finally Glen and I decided on using some sort of Listener or
broadcast mechanism, and after fiddling around with an awful polling
mechanism and some non-working listener contraptions I decided to go
with the good old Observer - Observable pattern.
This was still some pain in the <lower body part> to get to work
because we still had this synchronisation mechanism from the Tapas
Stone Age that does basically this: whenever one saves an object, it
is bounced back by Casa and used to refill the screens. This little
trick does, however, not give you the same instance back of the
ClinicalDoc, even though it is the *same* ClinicalDoc from the user's
perspective. But the Observer pattern does come in handy here as
well, because we can make every screen an Observer for the
ClinicalDocument. Once you save it, its changed flag is set and every
Observer that is registered on it gets notified and is passed the
same instance to do with it whatever we desire: to refresh the
screen, to name one thing. Bingo! Bango!
So - I am happy to tell that it works now.
Cheers
Maike
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