Re: Yahoo - Informix Revitalizes 4GL Application Development Too

What we do now for reports, invoice creations and other batch type processes, is to create a GUI front end in Java. Then we strip off the small front end (if any) in these 4GL programs and start them from Java using RMI. This is just greate. It works nice and gives you a true GUI. As we have time for it we recreate programs fully in Java, but still use RMI to execute the heavy part on the server. Using this scheme we are also about to create a realy sophisticated job control system that can run Informix 4GL as well as Java programs (or rather objects in threads) at scheduled times, asyncronously, with full dependency control, parameter passing and setup, success/failiure control and so on all executing on any number of servers and controlled from any client. This is fun. More fun than we have ever had. It's so easy to do so many things you could previously only dream of using Java. I am somewhat at a loss why more people don't simply try. You still have a problem with 4GL programs that are mainly interactive applications. You will have to rewrite those from the ground up. You do however not only get "GUI because that's what the customer want". You also will be able to do fundamentally new things that wasn't exactly easy if at all possible with 4GL. How about filling a grid (a screen array in 4GL) in a separate thread while the user continues working? Cashing query results locally or on a server while the user works? Threading for other purposes and multi tier programming? Even though such things would be possible in C/C++ I wouldn't attempt it. Java is simply nice. If your interactive application contains significant functions that are not interactive it will in some cases be possible to strip them out and run them on the server via RMI and even return some results to your new Java application. The easy way is if they can be executed as programs on your Unix server. It's harder if they have to be executed as functions. You would have to use JNI (Java Native Interface) for that. We don't intend to do that. If you expect to ever be able to get a true GUI application out of your 4GL code you are lost anyway. It can't be done. All solutions are and will forever be stop gap solutions anyway. True GUI applications need event driven programming which isn't supported by the 4GL input and other UI statements. Whatever you do you will eventually have to rewrite completely at least the interative parts of your applications in a language supporting event driven programming. We have selected to bite the bullet and do this up front. If you don't you should be aware that some of the solutions offered hardly allow you to do this. 4J at least used to be an example of that. May be they have changed latly. With SuperNova you do at least have a language to do it in. However as I understand it that also requires a complete rewrite to get to a real GUI using event driven programming in your own code. And then, in this day and age, this language isn't even object oriented. May be not too bad, but no advantage exactly. VB, Delphi, PowerBuilder and the others are out of the question. They don't support Unix server side programming (no not even PowerBuilder as the number of servers supported and the functionality is so limited). They also don't have simple threading (VB's attempts aren't up to it - not yet anyway) and lacks other things you get allmost for free in Java. Next, with the exception of VB, they will be in for a hard time in competing with Java development tools. As a complete rewrite is the only eventual solution whatever you do, we have found our solution best for us. Your milage may wary (but I realy doubt it can wary all that much in the end although it may seem hard in the beginning). On Fri, 8 May 1998 07:47:03 -0600, "Randy L. Cross" <rcross@fssd.fssc.k12.ar.us> wrote: > >On 8 May 98 at 10:02, Billy Wheeler wrote: >> >> How about what do we do >> with our millions of lines of 4GL code? Etc. >> >> -- >This is exactly where I'm at. All our applications are pure 4GL. >Users are screaming for GUI. New Era is kaput. Whatcha gonna do? > >Been looking at VB and other stuff, but I don't trust Micro$oft as >far as I could throw Bill Gates. Can't imagine having the business >(and my income) depend on a MS product. > >The search goes on...... > >rc > > Nils Myklebust NM Data AS Norway E-mail: Nils.Myklebust@nmdata.com FAQ at: http://www.iiug.org/techinfo/faq/faq_top.html (Now with ODBC info under "Third party products".)