Re: Pete's web5250 was->Re: Business Developers was ->Re: IBM Gives RPG Devotees Their Own Café

From: Aaron Bartell
Do you feel that drop-downs are a waste of time?

No, it's not that. It's just that Niels is getting close to having a turn-key Emulator. One that you could just plug-in and add to a Web site. And ExtJS components already offer a top-grade, professional look.

On the other hand, it appears that Niels may also be offering an interface for developers. One that could potentially be used as server-based middle-ware between a browser client and a 5250 application. And the developer would have the leeway to modify the interface.

If I understand correctly, the "C" wrapper around the 5250 interface could be a big boon. It maps the 5250 data stream to server-side components that can be referenced from RPG middle-ware modules, but shields all the nasty 5250 bits from the RPG coder.

Your RPG middle-ware would just work with arrays of UI components (input-output fields, attributes, and other screen elements), similar to the TN5250J bean that Pete Helgren was working with. In Niels example, there's no J2EE middleware, which is a lot more efficient.

And Niels also came up with an interface between an RPG module and the ExtJS client. But I suppose one could come up with their own messaging protocol between any kind of browser client and any kind of application server, if this were an open-source project.

If you want to add an interface for drop-downs, and have the time, and need more than a plug-in emulator, then that seems to be an option. You could modify the interface on a case by case basis.

For example, your browser client might get the base screen provided by the 5250 program, then evoke an AJAX request to fill in a drop-down list. The RPG module in the middle could handle that request without even notifying the 5250 program (which would be waiting on a "read" opcode). Hey, it's middle-ware. And you write it. You can do what you want.

Nathan.