Re: Web Services Adapter for 5250 Applications

Nathan Andelin wrote:

Joe,

Thanks for the explanation of adapters for 5250 applications. You've obviously put more thought and work into this than I, so I'll defer to your expertise.

Yeah, I've been doing this for a while. The interesting thing is that no matter what you do in the web world - be it a new user interface, a client/server model or simply exposing your processes as services - you have to move from the 5250 screen-at-a-time paradigm to a message-based process-oriented model. Once you understand that, you can then review your requirements and determine which is the best route to take.

Regarding my comment about the Zend 5250 Bridge being unwieldy for developing web services adapters, that was just my first impression, and I should probably defer to Jon Paris or somebody from Zend, if they'd like to jump in. The thing that triggered my comment was the understanding that the Webfacing server doesn't know display file "field names", so the 5250 bridge generates names using sequential numbers based on field positions on the screen. If positions change sometime down the road, the developer would need to change the names in his PHP script. It seemed like an iterative, investigation process. Connect to the screen. Query the screen objects. Mentally map generated names to the names in the display file, and write code based on your investigation. And change your code when the screen changes.

Yeah, that does sound ugly. I can't imagine that's really how they designed it, unless they don't even examine the display file object and instead just work off the 5250 data stream.

Joe