"Smola" <supersmola...@VEinet.hr> wrote in message <news:avmdq4$56s$1@garrison.globalnet.hr>...
> "Bj?rge S?ther" <bjorge@hahaha_itte.no> wrote in message
> news:kHxT9.9098$CG6.172061@news4.e.nsc.no...
> > DataSnap (should mention that I'm still on D5) is still quite immature,
> > IMHO.
> They had various bugs in D6 but the patch fixes it.
> > You may run into various problems, and you'll have a hard time trying to
> > figure out what's going on under the hood. Especially handling of
> > constraints is messy, as you have too little control over what's been
> taken
> > care of in client and what's been handled in AppServer.
> > In fact, I've been forced to modify both dbclient.pas and provider.pas to
> > make it work.
> > This you may live with.
> May be. But however our app worked pretty much well. It's a financial/stock
> application (I don't know the right engllish expresions).
> > What's harder is simply how to "layer" the application ? By default, you
> > find yourself maintaining all 3 layers simultaneously, a true nightmare.
> Yes, in deed.
> > - How do you put "business rules" in middle layer without ending up with a
> > totally imbesile client ? Everything looks great until you push 'Save'
> > button, then you get all info on how things *ought* to be...
> Imbecile client + server optimistic locking problems. These are the things
> that you just have to plan with. They're after all a web-application
> characteristic as well.
> > - How do you make one field's value control appearance of controls
> (enabled,
> > etc. ?) and calculate descriptive values ? In client, of course, but
> aren't
> > those "business rules" as much as a "valid date check" or a "maximum
> credit
> > check" ?
> > Nice theory, "putting business rules in middle layer", but I have yet to
> see
> > a good strategy described.
> There are two kinds of business rules - client and server. :-)))
> > Working with DataSnap may seem simple & powerful, but creating a large
> > scale, working, maintainable application is a real challenge.
> Emphasis on maintainable. In my expirience companies try to port their apps
> from two-tier architecture to three-tier without even completing they app or
> with an app that is poorely designed. But of course, people are often
> incompetent.
> :-(
> And a word about Websnap. It is functional and robust. You can make a
> web-app pretty fast and simple and maintaniable and all. But Borland didn't
> realize that people don't want that, people want friendly GUI, DHTML, CSS
> and all other neat stuff that once they get into your websnap app
> requrements are real pain in the ass to mantain and design.
> That's my 2c, dotNET is what I like better.
