• Guru Classic: Triggers – Allow Repeated Change

  February 13, 2019 Paul Tuohy

  Author’s Note: This article was originally published in November 2013. This has always been one of my favorite techniques for data modernization. I only wish I had thought of it back in the days of Y2K! The content of the article has been updated for free form RPG and some of the coding enhancements that have been introduced into RPG since 2013. 

  Recently, during a modernization project, I have been making use of the Allow Repeated Change (ALWREPCHG) option with before triggers. ALWREPCHG allows a before trigger to make changes to the record being inserted or updated, and that lets …

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• Guru Classic: Who Needs Custom Perspectives In RDi?

  February 13, 2019 Susan Gantner

  I often talk to people who are confused about RDi perspectives, so I thought this two-part series on why and how to create and use your own custom perspectives would be a good one to update. Very little has changed since the original publication of this first part, but I’ve updated the screen shots and addressed one or two small differences in recent releases. This version assumes you are running at least RDi 9.5

  Who needs custom perspectives in RDi? Just about everyone. At least everyone could probably benefit from them. As you know if you’ve read my earlier tips, …

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• Guru Classic: Automatic Or Static Storage?

  January 16, 2019 Susan Gantner

  Author’s Note: This tip was first published in August 2008. One thing that has changed in the intervening 10-plus years is that I find a lot more RPGers regularly using subprocedures now. Something that hasn’t really changed much is that many of those using subprocedures still don’t fully understand the behavioral differences between automatic and static storage. The concepts and handling of automatic versus static storage haven’t really changed. So the only modifications I’ve made for this reprise of the tip is to update the style of the code example.

  If you write RPG subprocedures, you should know about the …

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• Guru Classic: A Bevy of BIFs – %SCAN and %CHECK

  January 16, 2019 Jon Paris

  Many RPG programmers seem to get confused about the usage and operation of a number of built-in functions (BIFs). In particular the BIFs %XLATE, %REPLACE, %SCAN, and %CHECK seem to cause a lot of confusion. In this tip, I focus on %CHECK and %SCAN. I decided to re-visit this particular tip because of the recent introduction of %SCAN’s companion BIF %SCANR and a related enhancement to %SCAN itself. More on this later.

  The %SCAN BIF has been with us since V3R7, when it was introduced along with %EDITC and %EDITW, to improve string handling. %CHECK, on the other hand, is …

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• Guru Classic: Call Again And Again And Again . . .

  January 16, 2019 Paul Tuohy

  Author’s Note: This article was originally published in October 2011 and recently came to mind when I had a discussion with a programmer bemoaning the fact that he could not (so he thought) have a recursive process in RPG. The content of the article has been updated for free form RPG and some of the coding enhancements that have been introduced, into RPG, since 2009. 

  In programming terms, recursion is the process whereby a function may call itself. Traditionally, this is something we are not used to in RPG. Programs and subroutines cannot call themselves. Or if you did somehow …

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• Guru: A Bevy of BIFs – %Dec to the Rescue

  August 1, 2018 Susan Gantner

  Author’s Note: This tip was first published back in 2009. I’ve updated the code examples here to use free format declarations. In addition I’ve added the potential use of %ScanRpl, which didn’t exist at the original publication date.

  More and more in RPG applications these days, it seems we need to process data that comes from “the dark side.” Translation: from a non-i system. This data could be coming from a browser screen via an RPG CGI program, from a CSV (comma-separated values) flat file, from an XML or JSON document, or myriad other ways. One thing these dark sources …

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• Guru: An Introduction to RPG’s XML-INTO, Part 1

  August 1, 2018 Jon Paris

  Author’s Note: The original version of this article was written in the V6 timeframe and included references to V5R4. References to the V5R4 limitations have been removed from this updated version. I have also updated the data definitions to take into account RPG’s ability for the direct coding of nested data structures rather than having to use LikeDS as before.

  RPG IV’s built-in XML support has been available for some time now, having been originally introduced with V5R4 back in 2006. However, it wasn’t until the advent of V6 with its removal of many of RPG’s size limits that it …

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• Guru: Getting The Message, Part 1

  August 1, 2018 Paul Tuohy

  Author’s Note: This article was originally published in October 2009. Since then I have worked on many modernization projects with many clients and, in every one of those projects, we have used some form of the contents of this (and the following) article. The content of the article has been updated for free form RPG and some of the coding enhancements that have been introduced, into RPG, since the original publication of this piece.

  When we look at modernizing applications (or writing new applications) one of the basic principles is to tier the application — i.e., separate the interface — …

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• Introducing Four Hundred Guru Classic

  July 30, 2018 Timothy Prickett Morgan

  Application modernization is all the rage in the IBM i market these days, and for good reason. There is free form RPG that opens up new possibilities, and a slew of new programming languages and frameworks from the open source community that have been added to the platform. Just like some applications need to be updated and some don’t, some tech tips and tricks need to be updated while others don’t. Four Hundred Guru Classic is a new edition of The Four Hundred that is going to reach back into the archive of tech tips and tricks and amalgamate and …

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