02
Sat, Nov
2 New Articles

RPG Academy: Write Better Code - More Tips for Organizing Your Modules and Service Programs

RPG
Typography
  • Smaller Small Medium Big Bigger
  • Default Helvetica Segoe Georgia Times

The previous article of the series discussed module and service program organization. It’s now time to do the same for binding directories.

Let’s start with a quick recap of binding directories. Your modules will be composed of procedures. Some of these procedures are going to be available to the outside world; these are the module’s exports. The module’s procedures might call procedures from other service programs; these are the module’s imports. The problem is that the compiler has no idea where to find those procedures that your module’s code is calling, if they don’t belong to the same module/service program.

A binding directory is a list of modules and/or service programs that the compiler will use to discover where to get the information it needs about the module’s imports. Regardless of how your modules are organized, you can create as many binding directories as you see fit. There are a couple of ways to go about this:

First method: Create one binding directory per application. You include all the service programs of the application, no matter how they’re organized, in one big binding directory. This way, you use the same binding directory in the creation of all programs and service programs of that application. You might have a few more binding directories, dedicated to tools like CGIDEV2 or MIME&MAIL, for example.

This scenario is the simpler of the two to manage, because there are only a few binding directories. You might think that the compiler will take longer to run through the binding directory to “connect the dots” between your program and the binding directory; however, this is not true, because the binding directory doesn’t contain the actual objects. It’s a list, not a repository, so the compiler will pick only those that are really needed to create the program, and ignore the rest.

Second method: Create one binding directory per program/service program. You have a tailored binding directory per program/service program, which includes only the objects (modules and/or service programs) needed to create each specific program or service program. In this scenario, the binding directory serves a double purpose, both “connecting the dots” as I explained in the other scenario, and serving as “mini-documentation” in conjunction with the procedures it holds.

Let me explain what I mean with a little example. Imagine that you have a procedure named Clc_Delivery_Fee, and the binding directory of the service program its module belongs to includes another service program named ORDDBO. Assuming ORDDBO stands for order management database operations, you can conclude that the aforementioned procedure uses data from the order files to calculate the delivery fee. This is an assumption impossible to do in the other scenario, because the binding directory has a much broader scope. However, you have a lot more binding directories to manage than in the previous scenario.

Personally, I favor the one-binding-directory-per-service-program scenario. That’s probably because I’ve worked in an ILE environment configured that way for many years, so I’m more comfortable with it. I also prefer the one-service-program-per-module approach for the same reasons. This approach standardizes object-creation commands, it helps you follow a coherent design and development methodology, and it’s easy to use, once you get used to it and you document it properly. But that’s just me! Because you’re probably not starting from scratch, your application might have some sort of standard that can be extended to accommodate service program and binding directory organization.

I’d like to take a moment to do a quick recap of what was discussed in the last few TechTips before diving into the much-awaited topic of documentation:

  • Following some sort of naming convention facilitates communication, helps integrate new members of the team more quickly, and reduces the time spent trying to “figure out what that variable is used for.” Proper variable prefixes and names (instead of x, y, and i) improve the code’s readability and maintainability.
  • Similarly, using descriptive and structured names for your procedures is very helpful; it’s a big step toward turning your code into an easy to read, easy to maintain narrative. (Free-format will also help with this, as you’ve seen in the “/FREE Your Code” subseries.)
  • Using prefixes for files goes a long way when it comes to understanding what’s going on in your data; quickly figuring out if that is a physical or logical file just by looking at its name will save programmers (and users) some valuable time.
  • Organizing your code is of paramount importance. You need to find a logical and intuitive way to organize your procedures into modules and your modules into service programs so that when you need to use them to build a new program, the task is almost as easy as putting some Lego blocks together. And don’t forget the binding directory organization discussed earlier in this article!

You might think that these rules are not relevant in your particular environment, but over time you’ll see that they really help save time (and quite a few headaches) whenever you have to go back to code you, or a fellow programmer, wrote some time ago.

However, when it comes to figuring out what the code does, proper documentation is critical! Stay tuned, because the next TechTip will cover this interesting and often overlooked topic.

Rafael Victoria-Pereira

Rafael Victória-Pereira has more than 20 years of IBM i experience as a programmer, analyst, and manager. Over that period, he has been an active voice in the IBM i community, encouraging and helping programmers transition to ILE and free-format RPG. Rafael has written more than 100 technical articles about topics ranging from interfaces (the topic for his first book, Flexible Input, Dazzling Output with IBM i) to modern RPG and SQL in his popular RPG Academy and SQL 101 series on mcpressonline.com and in his books Evolve Your RPG Coding and SQL for IBM i: A Database Modernization Guide. Rafael writes in an easy-to-read, practical style that is highly popular with his audience of IBM technology professionals.

Rafael is the Deputy IT Director - Infrastructures and Services at the Luis Simões Group in Portugal. His areas of expertise include programming in the IBM i native languages (RPG, CL, and DB2 SQL) and in "modern" programming languages, such as Java, C#, and Python, as well as project management and consultancy.


MC Press books written by Rafael Victória-Pereira available now on the MC Press Bookstore.

Evolve Your RPG Coding: Move from OPM to ILE...and Beyond Evolve Your RPG Coding: Move from OPM to ILE...and Beyond
Transition to modern RPG programming with this step-by-step guide through ILE and free-format RPG, SQL, and modernization techniques.
List Price $79.95

Now On Sale

Flexible Input, Dazzling Output with IBM i Flexible Input, Dazzling Output with IBM i
Uncover easier, more flexible ways to get data into your system, plus some methods for exporting and presenting the vital business data it contains.
List Price $79.95

Now On Sale

SQL for IBM i: A Database Modernization Guide SQL for IBM i: A Database Modernization Guide
Learn how to use SQL’s capabilities to modernize and enhance your IBM i database.
List Price $79.95

Now On Sale

BLOG COMMENTS POWERED BY DISQUS

LATEST COMMENTS

Support MC Press Online

$

Book Reviews

Resource Center

  • SB Profound WC 5536 Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application. You can find Part 1 here. In Part 2 of our free Node.js Webinar Series, Brian May teaches you the different tooling options available for writing code, debugging, and using Git for version control. Brian will briefly discuss the different tools available, and demonstrate his preferred setup for Node development on IBM i or any platform. Attend this webinar to learn:

  • SB Profound WP 5539More than ever, there is a demand for IT to deliver innovation. Your IBM i has been an essential part of your business operations for years. However, your organization may struggle to maintain the current system and implement new projects. The thousands of customers we've worked with and surveyed state that expectations regarding the digital footprint and vision of the company are not aligned with the current IT environment.

  • SB HelpSystems ROBOT Generic IBM announced the E1080 servers using the latest Power10 processor in September 2021. The most powerful processor from IBM to date, Power10 is designed to handle the demands of doing business in today’s high-tech atmosphere, including running cloud applications, supporting big data, and managing AI workloads. But what does Power10 mean for your data center? In this recorded webinar, IBMers Dan Sundt and Dylan Boday join IBM Power Champion Tom Huntington for a discussion on why Power10 technology is the right strategic investment if you run IBM i, AIX, or Linux. In this action-packed hour, Tom will share trends from the IBM i and AIX user communities while Dan and Dylan dive into the tech specs for key hardware, including:

  • Magic MarkTRY the one package that solves all your document design and printing challenges on all your platforms. Produce bar code labels, electronic forms, ad hoc reports, and RFID tags – without programming! MarkMagic is the only document design and print solution that combines report writing, WYSIWYG label and forms design, and conditional printing in one integrated product. Make sure your data survives when catastrophe hits. Request your trial now!  Request Now.

  • SB HelpSystems ROBOT GenericForms of ransomware has been around for over 30 years, and with more and more organizations suffering attacks each year, it continues to endure. What has made ransomware such a durable threat and what is the best way to combat it? In order to prevent ransomware, organizations must first understand how it works.

  • SB HelpSystems ROBOT GenericIT security is a top priority for businesses around the world, but most IBM i pros don’t know where to begin—and most cybersecurity experts don’t know IBM i. In this session, Robin Tatam explores the business impact of lax IBM i security, the top vulnerabilities putting IBM i at risk, and the steps you can take to protect your organization. If you’re looking to avoid unexpected downtime or corrupted data, you don’t want to miss this session.

  • SB HelpSystems ROBOT GenericCan you trust all of your users all of the time? A typical end user receives 16 malicious emails each month, but only 17 percent of these phishing campaigns are reported to IT. Once an attack is underway, most organizations won’t discover the breach until six months later. A staggering amount of damage can occur in that time. Despite these risks, 93 percent of organizations are leaving their IBM i systems vulnerable to cybercrime. In this on-demand webinar, IBM i security experts Robin Tatam and Sandi Moore will reveal:

  • FORTRA Disaster protection is vital to every business. Yet, it often consists of patched together procedures that are prone to error. From automatic backups to data encryption to media management, Robot automates the routine (yet often complex) tasks of iSeries backup and recovery, saving you time and money and making the process safer and more reliable. Automate your backups with the Robot Backup and Recovery Solution. Key features include:

  • FORTRAManaging messages on your IBM i can be more than a full-time job if you have to do it manually. Messages need a response and resources must be monitored—often over multiple systems and across platforms. How can you be sure you won’t miss important system events? Automate your message center with the Robot Message Management Solution. Key features include:

  • FORTRAThe thought of printing, distributing, and storing iSeries reports manually may reduce you to tears. Paper and labor costs associated with report generation can spiral out of control. Mountains of paper threaten to swamp your files. Robot automates report bursting, distribution, bundling, and archiving, and offers secure, selective online report viewing. Manage your reports with the Robot Report Management Solution. Key features include:

  • FORTRAFor over 30 years, Robot has been a leader in systems management for IBM i. With batch job creation and scheduling at its core, the Robot Job Scheduling Solution reduces the opportunity for human error and helps you maintain service levels, automating even the biggest, most complex runbooks. Manage your job schedule with the Robot Job Scheduling Solution. Key features include:

  • LANSA Business users want new applications now. Market and regulatory pressures require faster application updates and delivery into production. Your IBM i developers may be approaching retirement, and you see no sure way to fill their positions with experienced developers. In addition, you may be caught between maintaining your existing applications and the uncertainty of moving to something new.

  • LANSAWhen it comes to creating your business applications, there are hundreds of coding platforms and programming languages to choose from. These options range from very complex traditional programming languages to Low-Code platforms where sometimes no traditional coding experience is needed. Download our whitepaper, The Power of Writing Code in a Low-Code Solution, and:

  • LANSASupply Chain is becoming increasingly complex and unpredictable. From raw materials for manufacturing to food supply chains, the journey from source to production to delivery to consumers is marred with inefficiencies, manual processes, shortages, recalls, counterfeits, and scandals. In this webinar, we discuss how:

  • The MC Resource Centers bring you the widest selection of white papers, trial software, and on-demand webcasts for you to choose from. >> Review the list of White Papers, Trial Software or On-Demand Webcast at the MC Press Resource Center. >> Add the items to yru Cart and complet he checkout process and submit

  • Profound Logic Have you been wondering about Node.js? Our free Node.js Webinar Series takes you from total beginner to creating a fully-functional IBM i Node.js business application.

  • SB Profound WC 5536Join us for this hour-long webcast that will explore:

  • Fortra IT managers hoping to find new IBM i talent are discovering that the pool of experienced RPG programmers and operators or administrators with intimate knowledge of the operating system and the applications that run on it is small. This begs the question: How will you manage the platform that supports such a big part of your business? This guide offers strategies and software suggestions to help you plan IT staffing and resources and smooth the transition after your AS/400 talent retires. Read on to learn: