Four Hundred Guru Classic Archives

Guru: RPG Sorting and Searching, A 7.2 Update

September 5, 2018 Susan Gantner

Author’s Note: This is the second update I’ve done to a tip I originally wrote back in 2008. In 2010, I updated the code to use SORTA with array data structures. Here in 2018 I’m updating it once more — this time to use free-form declarations in place of the D specs, including a more obvious way to code the nested data structure used in some of the examples and references to more recent tips for handling very large arrays. The 2010 version was entitled “. . . A 7.1 Update.” I’ve renamed this one as “. . . A …
Read more
Guru: An Introduction to Processing XML With RPG, Part 3

September 5, 2018 Jon Paris

Author’s Note: In part 1 and part 2 of this XML series, I introduced you to the basics of using RPG’s XML support. In this tip we begin to explore some of the challenges that you may face when processing commercial XML documents, and the support XML-INTO offers to handle them. In particular we will be reviewing how to ignore parts of the document through the use of the path= %XML option. We will also review how to handle XML documents that make use of namespaces and how to handle XML element names that include characters that are not valid …
Read more
Guru: Handling Constraint Violations In RPG

September 5, 2018 Paul Tuohy

Author’s Note: The contents of this article were originally published as two separate articles – Handling Constraint Violations in RPG and Handling Constraints Revisited. 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.

Constraints have been around for a long time but apparently have not quite made it into every programmer’s tool kit. This is partly explained by the fact that implementing constraints in an existing application can be tricky, but it doesn’t explain why constraints are not used extensively in new …
Read more
Guru: Three Little Words That Simplify Debugging

August 29, 2018 Susan Gantner

Author’s Note: The original version of this tip first appeared in March 2007. That was three renames ago for the toolset we now know as RDi. (It was WDSC then). Although RDi has seen many significant enhancements in the intervening years, not much about starting a debug session has changed. But the number of RPGers now using RDi for editing their code has grown dramatically, and many recent converts still struggle with getting a debug session started. So I think this tip bears repeating — with some name changes, updated images and relevant functional updates here and there.

I had …
Read more
Guru: An Introduction to Processing XML With RPG, Part 2

August 29, 2018 Jon Paris

In the first part of this series for Guru Classic, I introduced you to the basics of using RPG’s XML-INTO op-code. In that tip I showed how the provision of a count provided by RPG in the PSDS can be used to determine how many of a repeating element were processed.

However, as I noted at the time, this can only be used when handling a repeating outer element. But what if there is a repeating element within each of those outer elements? In this second part of the series we will be studying how to handle those situations. …
Read more
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 …
Read more
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 …
Read more
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 — …
Read more
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 …
Read more

Content archive

Recent Posts

Subscribe

Pages

Search