Struts for Motif. Okay, wash my mouth out with SOAP!
But, look, lots of neat, old X/Motif applications were written using the MVC
architecture.
What good did it do X, Motif, ... or MVC?
And, don't try blaming it all on the X Server being such a heavy "client".
On the other hand, don't try to claim that the Web-way is the only way.
[We could also consider Struts for Swing, but that clouds the argument I am
about to make.]
A Motif MVC app I recently worked on had MVC features similar to Struts,
like an action map "digester". Well, the Motif app digester was written in
awk and it was a preprocessor. The mappings got compiled into the code.
But it was similar, a nice high level view of the internal data
architecture.
Unfortunately, I also see some disturbing similarities between the
weaknesses of MVC Motif (as commonly programmed) and Struts, such as
1. A difficult and impoverished widget set.
For instance, do we have a high-level Tree widget to plug into Struts?
Having third-party Tree widgets and scripting hacks for Trees didn't make
Motif competitive with the Win-mill. ( ?? "COMpetitive" ??)
2. Ad hoc Database-to-Model mappings.
For instance, if a number of browser sessions, perhaps hierarchically
related browser sessions, are looking at the same Persistent EJBs, how do
these sessions coordinate their separate (hierarchical) Models? Their
database updates? Their screen Updates? Is this to be left to the realm
of "Business Logic"? It's system logic, for sure. It invites trouble to
let the bit jockeys be responsible for getting this right, for buggering the
MVC.
The Motif MVC app I worked on used the windowing hieirachy in X/Motif to
build a Model hierarchy of database views. This was very ad hoc, very
quirky and quite buggy, but nice. Or so I thought. The nuances escaped
many in the user community. And, eventually the programmers also lost track
of the ad hoc programming needed to sustain the Model hierarchy. So it
goes.
But, jeez, it did make for a very lively GUI when it all went well, with
model changes rippling from window to window. Made Win-doze apps look
absolutely static in comparison. Unfortunately, I don't see much (yet) in
Struts to make a more dynamic display out of (hierarchical) web browser
sessions. Or, is this just a feature in search of an audience??
Dan Connelly
