Re: Web Services Adapter for 5250 Applications

["Evan Harris" <spanner@xxxxxxxxxx>]

Hi Nathan

As others have said, the adapter wouldn't know field names, but once you've
done the work to provide an updated UI fed by the adapter, then the
requirements to change the original green screen for presentation purposes
would no longer be there - you'd make the changes downstream on the other
end of the adapter.

If the original program requires changes that will modify the data stream
the adapter uses, then that would be a signal that it's time to move beyond
the adapter *for that process*.

Regards
Evan Harris



-----Original Message-----
From: web400-bounces@xxxxxxxxxxxx [mailto:web400-bounces@xxxxxxxxxxxx] On
Behalf Of Nathan Andelin
Sent: Thursday, 3 July 2008 3:05 a.m.
To: Web Enabling the AS400 / iSeries
Subject: Re: [WEB400] Web Services Adapter for 5250 Applications

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.

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.

Nathan M. Andelin