29
Fri, Nov
0 New Articles

Practical Web: How Hard Are Web Languages, Anyway?

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

We all know we need to program for the Web, but we hear all kinds of stories about how hard Web languages are. This article compares two of the most popular options.

 

The Web beckons. The green-screen has been more than adequate for years, even decades, but the pressure for something more modern keeps building. If you don't figure out how to expose your business logic via some sort of browser-based user interface, the Windows crowd is going to demand a GUI solution. That means the business logic starts migrating away from RPG. Not long after that, the database itself follows, and it's goodbye IBM i. So you need a Web solution and you need it now, but how do you get there? Today I'll compare the fundamental characteristics of the two most popular options for the IBM i community.

This Article Is About 3GLs

I bet you thought this would be about EGL, didn't you? Well, surprise! Even though I find EGL to be by far the easiest language in which to develop Web applications, for the purposes of this article I'm going to stay away from 4GL solutions. Most tools today, whether it's a commercial solution like BCD or an IBM tool like EGL, build on some underlying language. Even ILE-only tools like IceBreak build on top of RPG.

 

I believe you should understand the underlying infrastructure for anything in your enterprise, so today we're going to assume you're going to roll your own solution from a 3GL. According to TIOBE, of the languages used for the Web, the two most popular are Java and PHP, and both are available on the IBM i. So let's start with Java. While this article is about Web programming, for the purposes of comparison I'm going to present snippets of code that compare the fundamental aspects of the languages.

Let's Start With Java

020211PlutaFigure1

Figure 1: This simple Java code creates an abstract class, extends it, and then uses it. (Click image to enlarge.)

 

In Figure 1, you'll see some very barebones code that exemplifies the basics of object-oriented programming (OOP) in Java. In Java, you are supposed to model your code by modeling real concepts. In this case, I want to create an object that can calculate its own area. It's not Web-oriented to any degree or even business-oriented; it's just a simple example. But it illustrates some very pertinent concepts. First and foremost is the idea of a class. A class is an OOP concept that acts as a container for program logic. You segregate related code into a class and then use that class along with other classes to build your business logic. The nifty part about OOP is that you can reuse that code by extending the class. Extending a class (or "subclassing") means that I create a new class that inherits the behavior of the parent class. In this case, I have an abstract class called Shape whose primary attribute is that it has a size that can be set. The Shape class exposes a method called "setSize," which lets the programmer set the size. Shape also defines an abstract method named getArea. An abstract method is one that must be implemented by the children. An abstract class is one that is never instantiated directly; only its concrete children can be created. Typically, an abstract class defines the general characteristics common among several related children. In this case, all the shapes have a size, so we implement the size logic in the abstract parent class. The Square class is the concrete descendant of Shape. The minimum a concrete subclass has to do is to provide concrete implementations of the abstract methods. In this case, the getArea method implements this simple formula: area equals size squared. The top part of the figure shows an actual implementation of the code: it creates an object of type Square, sets the size to 2, and then prints the area.

 

You'll note that certain keywords are available to facilitate this development. Keywords like public, abstract, class, and extends have all been around in Java since its inception in the early 1990s. These keywords provide the fundamental underpinnings to all of the OOP capabilities of the language. The terms are similar to those in C++, but there are significant differences. For example, C++ uses the term "virtual" rather than abstract. Where Java defines the visibility (public or private) of each variable or method, C++ classes have defined sections in which all of the variables share the same visibility. The differences are primarily syntactic, but it's clear that Java was written specifically to support OOP, whereas C++ was more of a way to add classes to the already existing C language.

And Now for Something Completely Different—PHP!

020211PlutaFigure2

Figure 2: This is the same code as Figure 1, implemented in PHP.

 

Actually, the title of this section is a little tongue-in-cheek. If you look at the two code snippets side by side, you might be hard-pressed to immediately identify which is Java and which is PHP. Not only is the terminology the same, in many cases the syntax is similar or even the same. For example, defining the class Square as a subclass of the abstract class Shape uses exactly the same syntax: class Square extends Shape. When the new object model was added in PHP 5, it seems that they definitely took into consideration the popularity of Java.

 

You will notice a couple of syntactical differences. Java uses a dot (period) to denote a member variable or method (square.setSize) while PHP uses the "arrow" syntax ($square->setSize). The dot is already used in PHP to denote concatenation, so when OOP was added, they needed a different syntax. Another difference is that all variables start with a dollar sign ($). It's obvious what a variable is in PHP! Also, what Java calls a "method" PHP calls a "function." But these are primarily syntactical differences. Two other related differences are more subtle but more profound. First, nowhere in the PHP example do you see a definition of the variable $size. This is absolutely anathema to Java, which, like RPG, requires every variable to have a specific compile-time definition. This is called "static" typing, and Java is a statically typed language. PHP is not. PHP is a dynamically typed language, and this manifests both in that you don't need to specify variables at compile time and also that you don't need to specify types either on parameters to or return values from a function.

A Final Thought on Dynamic Typing

Some people prefer the more relaxed nature of dynamic typing, and some even argue that it makes programming more productive. I understand that, especially in a proof-of-concept or sandbox mode, it is easier to not have to define variables. But I disagree with the productivity claim, and I have a very simple example that will illustrate my reasoning. Let's make the equivalent single-line change to both the Java and the PHP code:

 

     Java: square.setSize("hello");

     PHP: $square->setSize("hello");

 

What happens? Well, because of the type mismatch, in Java this code does not compile. That's crucial. You can't even run this code. In PHP, however, you can run the code; type mismatches may cause a run-time error, but you can still run the code. Actually, in this case, you won't even get a run-time error; you'll get a value of zero, because PHP tries to convert the word "hello" to an integer and then silently fails. It's universally accepted that run-time errors require much more time to repair than compile-time errors: the more your compiler catches, the less you have to debug.

 

So back to the premise of the article. How hard is Web programming? Is one language harder to learn than the other? I don't believe that. Since the syntax of the two languages is nearly identical, any claim that PHP is easier to learn than Java seems to be a little bit hard to justify. So the next difference would be how easy the language is to use, and that pretty much boils down to the dynamic vs. static typing. I suppose that can be at least partly a personal preference. In the end, it really comes down to the old adage of "pay me now or pay me later." You may be able to bang out code a little quicker when you don't have to worry about variable types, but it might bite you in the end when a subtle error that would have been caught by static typing makes it into the run-time.

as/400, os/400, iseries, system i, i5/os, ibm i, power systems, 6.1, 7.1, V7,

Joe Pluta

Joe Pluta is the founder and chief architect of Pluta Brothers Design, Inc. He has been extending the IBM midrange since the days of the IBM System/3. Joe uses WebSphere extensively, especially as the base for PSC/400, the only product that can move your legacy systems to the Web using simple green-screen commands. He has written several books, including Developing Web 2.0 Applications with EGL for IBM i, E-Deployment: The Fastest Path to the Web, Eclipse: Step by Step, and WDSC: Step by Step. Joe performs onsite mentoring and speaks at user groups around the country. You can reach him at This email address is being protected from spambots. You need JavaScript enabled to view it..


MC Press books written by Joe Pluta available now on the MC Press Bookstore.

Developing Web 2.0 Applications with EGL for IBM i Developing Web 2.0 Applications with EGL for IBM i
Joe Pluta introduces you to EGL Rich UI and IBM’s Rational Developer for the IBM i platform.
List Price $39.95

Now On Sale

WDSC: Step by Step WDSC: Step by Step
Discover incredibly powerful WDSC with this easy-to-understand yet thorough introduction.
List Price $74.95

Now On Sale

Eclipse: Step by Step Eclipse: Step by Step
Quickly get up to speed and productivity using Eclipse.
List Price $59.00

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: