Comments on: “Subfiles in RPGIV” and Me http://www.rpgandprogramming.com/2009/05/subfiles-in-rpgiv-and-me/ Not Role Playing Games, but the RPG programming language and the craft of programming. Thu, 09 Sep 2010 04:33:24 +0000 http://wordpress.org/?v=2.6.3 By: Curtis Barron http://www.rpgandprogramming.com/2009/05/subfiles-in-rpgiv-and-me/#comment-315 Curtis Barron Fri, 10 Jul 2009 23:32:45 +0000 http://www.rpgandprogramming.com/?p=165#comment-315 If I understand your question correctly, you have created a subfile that consists of one or more screens of data, then scrolled to the end of the subfile. For the sake of discussion, let's say you created a subfile of 48 records, consisting of 16 records per screen. When you roll back, you are in within the subfile. You can scroll back and forth within these three screens. The operating system itself, not the program, is in control of the roll keys. Assuming you have input capable fields, you can update the data within the subfile with either of the methods mentioned in my post. In this case, the roll keys will kick in when you scroll forward (roll up) at the end of the subfile. If you are at the first screen, you can go no lower; you will probably get a keyboard error if you attempt to roll back. I'm not sure I've answered your question. If I haven't, let me know. If I understand your question correctly, you have created a subfile that consists of one or more screens of data, then scrolled to the end of the subfile.
For the sake of discussion, let’s say you created a subfile of 48 records, consisting of 16 records per screen. When you roll back, you are in within the subfile. You can scroll back and forth within these three screens. The operating system itself, not the program, is in control of the roll keys. Assuming you have input capable fields, you can update the data within the subfile with either of the methods mentioned in my post. In this case, the roll keys will kick in when you scroll forward (roll up) at the end of the subfile.
If you are at the first screen, you can go no lower; you will probably get a keyboard error if you attempt to roll back.
I’m not sure I’ve answered your question. If I haven’t, let me know.

]]> By: Mike Aiese http://www.rpgandprogramming.com/2009/05/subfiles-in-rpgiv-and-me/#comment-314 Mike Aiese Thu, 09 Jul 2009 03:31:37 +0000 http://www.rpgandprogramming.com/?p=165#comment-314 How do you "force" the current screen to get read as in this case. I put roll down and roll up keys in the DDS. I display screen 1 of the subfile and roll thru the subfile to EOF. Then roll back. How come the program does not process the roll down key. The subfile maintains control for all the roll down keys. I want to do some processing on the screens as I am rolling back. , How do you “force” the current screen to get read as in this case.

I put roll down and roll up keys in the DDS.

I display screen 1 of the subfile and roll thru the subfile to EOF.

Then roll back. How come the program does not process the roll down key. The subfile maintains control for all the roll down keys. I want to do some processing on the screens as I am rolling back.

,

]]> By: Kevin Vandever http://www.rpgandprogramming.com/2009/05/subfiles-in-rpgiv-and-me/#comment-300 Kevin Vandever Fri, 19 Jun 2009 06:36:58 +0000 http://www.rpgandprogramming.com/?p=165#comment-300 ReadC, Chain. I see both points. Good discussion. Just glad folks are still talking about subfiles. Thanks for mentioning the book. Kevin. ReadC, Chain. I see both points. Good discussion. Just glad folks are still talking about subfiles. Thanks for mentioning the book.

Kevin.

]]> By: Scott Klement http://www.rpgandprogramming.com/2009/05/subfiles-in-rpgiv-and-me/#comment-244 Scott Klement Fri, 15 May 2009 21:32:11 +0000 http://www.rpgandprogramming.com/?p=165#comment-244 I agree with you. I prefer to use CHAIN for each RRN instead of READC. If I use READC with SFLNXTCHG, I lose the ability to tell if the user did or didn't make changes, because SFLNXTCHG will cause unchanged records to pop up as changed. When I write subfile apps, I usually want to show the screen to the user after his keying is done, and only proceed to the next screen (or whatever) if the user has made no changes. I can't detect that condition if I use SFLNXTCHG. The CHAIN technique is more versatile. In 16 years of subfile programming, I've never had trouble with performance using CHAIN. Today, the thought of a performance problem is almost laughable. It's only 9999 records, after all... on today's computers, that's nothing. I agree with you. I prefer to use CHAIN for each RRN instead of READC. If I use READC with SFLNXTCHG, I lose the ability to tell if the user did or didn’t make changes, because SFLNXTCHG will cause unchanged records to pop up as changed.

When I write subfile apps, I usually want to show the screen to the user after his keying is done, and only proceed to the next screen (or whatever) if the user has made no changes. I can’t detect that condition if I use SFLNXTCHG. The CHAIN technique is more versatile.

In 16 years of subfile programming, I’ve never had trouble with performance using CHAIN. Today, the thought of a performance problem is almost laughable. It’s only 9999 records, after all… on today’s computers, that’s nothing.

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