Welcome!

Microsoft Cloud Authors: Elizabeth White, Yeshim Deniz, Serafima Al, Janakiram MSV, John Katrick

Related Topics: PowerBuilder, Microsoft Cloud

PowerBuilder: Article

Elegant Programming: The Art of Naming (Part 1)

Names should be self-explanatory

Give all entities mentioned in the code (DB tables, DB tables' fields, variables, classes, functions, etc.) meaningful, descriptive names that make the code easily understood. The names should be so self-explanatory that it eliminates the need for comments in most cases.

Use the words per and by as often as possible - they really simplify a developer's life. A variable's name li_cows_per_farm is better than li_total_cows, and a function name uf_retrieve_city_by_country tells us more than uf_retrieve_city, especially if it doesn't have parameters that supply the "by what" information.

Don't use abstract words like "actual" and "total' in variables names as they will madden you, forcing to spend extra time trying to understand what is "actual," what is "not actual" and which grouping level is "total" for. Is li_total_cows field total per barn? per farm? per village? per province? per country? per the Universe? If, for example, per farm, then how will you name the total per village? It's also "total"! So, don't write simply "total" - write total PER WHAT! Use only exact definitions that produce no (or minimum) questions, even if that results in longer variables names.

*** BAD code: ***

ldc_total_salary = ldc_actual_salary * ldc_total_hours

*** GOOD code: ***

ldc_salary_per_day = ldc_salary_per_hour * ldc_hours_per_day

Exact Meaning
Consistency

Don't produce different versions of a same entity name (like emp_id / employee_id, inv_num / invoice_num).

When you use values retrieved from database tables, try to name the corresponding variables exactly by the DB fields (of course, adding naming convention prefixes where needed). But you can use local variables' names more freely, especially when the coded logic is complicated while the tables fields are not informative enough (see the previous rule).

Long, Descriptive Names
The common, obvious practice is to give variables and functions short names. But, sometimes, there are situations when it makes sense to break that rule and use long, "real-English" names that will clearly describe what they are for.

For example, it can be done when a variable is in a rare use (like an instance var, which is referenced only a couple of times), but not a local var which is mentioned in the code many times. Anyway, don't be afraid to give long names any time you feel it will simplify working with the code. See the difference between:

is_main_filter = uf_get_main_filter()

and

is_filter_by_selected_row_in_summary_win = uf_get_filter_by_selected_row_in_summary_win()

As you can see, names of variables can tell the whole story. Even if it makes a line too long, there is no problem breaking it into two lines - it's better than looking at a variable and having no idea what is stored in it (or to search its declaration in hopes that a clarifying comment exists). But remember - names of that style should be an exception, not a rule.

Exact Action Timing
Names describing actions must express if the action should be done in the future or was done in the past.

Giving names to variables, don't force readers to guess an action timing. A good example of a bad variable name is lb_is_calculation. How must the condition "if lb_is_calculation then..." be understood? As you can see, there is no problem exists understanding what it means if the variable is named lb_is_calculation_done (lb_is_calculated) or in the imperative form - lb_do_calculation (or simply lb_calculate).

The common advice is to use words do..., ...to_do, perform..., execute..., ...to_apply, etc., for stuff that should take place in the future, and ...done, ...performed, ...executed, ...occurred, ...passed, ...applied, etc., for things that have taken place in the past.

Constants
Constants for [Meaningless] Application Codes

Don't hard code numbers if they are not apparent - use constants instead.

Okay, it's still possible to understand what "if li_inv_year > 2011..." or "if li_month = 4..." is but what do you want to say to a programmer who has written "if li_window_mode = 3..." or "if li_inv_status = 8..."?

Local and Instance Constants Management
Giving names to local and instance constants, divide the family prefix from the mnemonic description by two underscores.

Now let's discuss local and instance-scope constants. Their names must consist of two parts:

  • Group (or "family") - like "ORDER_STATUS" or "INVOICE_STATUS". A few constants of the same family can co-exist in the scope (for example, an order can have many statuses). In fact, it's a prefix before the main descriptive part.
  • Description (or mnemonic part) - like "OPEN" or "CLOSED". There can be many constants with the same description (for example, both - an order and an invoice - can have the status "OPEN").

Using two underscores (instead of one) to connect both parts will allow code readers to easily distinguish between them, especially when each part consists of a number of words. For example:

private:

constant string ORDER_STATUS__OPEN = "OPN"
constant string ORDER_STATUS__CLOSED = "CLS"
constant string ORDER_STATUS__CANCELED = "CNCL"

constant string INV_STATUS__OPEN = "OPN"
constant string INV_STATUS__CLOSED = "CLS"
constant string INV_STATUS__CANCELED = "CNCL"

Global Constants Management
Constants, used globally (in different parts of the application), must be declared in not-autoinstantiated NVOs - one NVO per each constants group (or "family") - and accessed via the automatically created global reference variable with the same name, without declaring additional variables and creating instances.

For example, you can have an NVO named n_color for color constants, n_order_status for order statuses constants, etc. It's a good idea to keep them all in one PBL so developers can easily check if the NVO for the group they need already exists or must be created. The constants are declared in the instance variables declaration section in a very straightforward way. Here is a possible set for n_order_status:

public:

constant string OPEN = "OPN"
constant string CLOSED = "CLS"
constant string CANCELED = "CNCL"

If you open any not-autoinstantiated class in the "View Source" mode, you can see that PowerBuilder automatically creates a global variable of that object's type with the same name as the class (PB doesn't know that we add "g" to global vars! :-D ). For example, if you create n_order_status class (not-autoinstantiated, remember?) and look at its source, you'll see the following line:

global n_order_status n_order_status

That's exactly the mentioned declaration of the global var. You don't need to declare a variable of the object each time you need to use a constant in your script - you already have a variable ready for use. That's how you mention a constant in the code:

n_order_status.OPEN

Looking pretty similar to enum of C# but, unfortunately, it's not an enumerated type; you cannot declare a function argument of type n_order_status and pass to that function one of the statuses (which is of type string) defined in the type - you can only pass a reference to n_order_status object, which doesn't solve the problem of passing type-safe arguments. You can make the argument of type string to pass a particular status, but this approach doesn't supply type safety - nothing prevents you from passing an invoice status or even the name of your cat...

Pay attention that PowerBuilder only declares a global variable; it doesn't create an object referenced by that variable. Practically it means that we can use only constants because they belong to a type (not an instance) definition (something similar to static data in C#). If you try to access an instance variable or a function of that global var, then you will get the "Null object reference" error. As opposed to C#, which will happen even if the function doesn't access instance data, so there is nothing like C#'s "static function" behavior in PowerBuilder.

For standalone constants (not belonging to any family) create one common NVO named, let's say, n_const.

More Stories By Michael Zuskin

Michael Zuskin is a certified software professional with sophisticated programming skills and experience in Enterprise Software Development.

Comments (0)

Share your thoughts on this story.

Add your comment
You must be signed in to add a comment. Sign-in | Register

In accordance with our Comment Policy, we encourage comments that are on topic, relevant and to-the-point. We will remove comments that include profanity, personal attacks, racial slurs, threats of violence, or other inappropriate material that violates our Terms and Conditions, and will block users who make repeated violations. We ask all readers to expect diversity of opinion and to treat one another with dignity and respect.


@ThingsExpo Stories
Leading companies, from the Global Fortune 500 to the smallest companies, are adopting hybrid cloud as the path to business advantage. Hybrid cloud depends on cloud services and on-premises infrastructure working in unison. Successful implementations require new levels of data mobility, enabled by an automated and seamless flow across on-premises and cloud resources. In his general session at 21st Cloud Expo, Greg Tevis, an IBM Storage Software Technical Strategist and Customer Solution Architec...
Nordstrom is transforming the way that they do business and the cloud is the key to enabling speed and hyper personalized customer experiences. In his session at 21st Cloud Expo, Ken Schow, VP of Engineering at Nordstrom, discussed some of the key learnings and common pitfalls of large enterprises moving to the cloud. This includes strategies around choosing a cloud provider(s), architecture, and lessons learned. In addition, he covered some of the best practices for structured team migration an...
Product connectivity goes hand and hand these days with increased use of personal data. New IoT devices are becoming more personalized than ever before. In his session at 22nd Cloud Expo | DXWorld Expo, Nicolas Fierro, CEO of MIMIR Blockchain Solutions, will discuss how in order to protect your data and privacy, IoT applications need to embrace Blockchain technology for a new level of product security never before seen - or needed.
Imagine if you will, a retail floor so densely packed with sensors that they can pick up the movements of insects scurrying across a store aisle. Or a component of a piece of factory equipment so well-instrumented that its digital twin provides resolution down to the micrometer.
In his keynote at 18th Cloud Expo, Andrew Keys, Co-Founder of ConsenSys Enterprise, provided an overview of the evolution of the Internet and the Database and the future of their combination – the Blockchain. Andrew Keys is Co-Founder of ConsenSys Enterprise. He comes to ConsenSys Enterprise with capital markets, technology and entrepreneurial experience. Previously, he worked for UBS investment bank in equities analysis. Later, he was responsible for the creation and distribution of life settle...
BnkToTheFuture.com is the largest online investment platform for investing in FinTech, Bitcoin and Blockchain companies. We believe the future of finance looks very different from the past and we aim to invest and provide trading opportunities for qualifying investors that want to build a portfolio in the sector in compliance with international financial regulations.
No hype cycles or predictions of a gazillion things here. IoT is here. You get it. You know your business and have great ideas for a business transformation strategy. What comes next? Time to make it happen. In his session at @ThingsExpo, Jay Mason, an Associate Partner of Analytics, IoT & Cybersecurity at M&S Consulting, presented a step-by-step plan to develop your technology implementation strategy. He also discussed the evaluation of communication standards and IoT messaging protocols, data...
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
In his session at 21st Cloud Expo, Raju Shreewastava, founder of Big Data Trunk, provided a fun and simple way to introduce Machine Leaning to anyone and everyone. He solved a machine learning problem and demonstrated an easy way to be able to do machine learning without even coding. Raju Shreewastava is the founder of Big Data Trunk (www.BigDataTrunk.com), a Big Data Training and consulting firm with offices in the United States. He previously led the data warehouse/business intelligence and B...
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
A strange thing is happening along the way to the Internet of Things, namely far too many devices to work with and manage. It has become clear that we'll need much higher efficiency user experiences that can allow us to more easily and scalably work with the thousands of devices that will soon be in each of our lives. Enter the conversational interface revolution, combining bots we can literally talk with, gesture to, and even direct with our thoughts, with embedded artificial intelligence, whic...
When shopping for a new data processing platform for IoT solutions, many development teams want to be able to test-drive options before making a choice. Yet when evaluating an IoT solution, it’s simply not feasible to do so at scale with physical devices. Building a sensor simulator is the next best choice; however, generating a realistic simulation at very high TPS with ease of configurability is a formidable challenge. When dealing with multiple application or transport protocols, you would be...
Smart cities have the potential to change our lives at so many levels for citizens: less pollution, reduced parking obstacles, better health, education and more energy savings. Real-time data streaming and the Internet of Things (IoT) possess the power to turn this vision into a reality. However, most organizations today are building their data infrastructure to focus solely on addressing immediate business needs vs. a platform capable of quickly adapting emerging technologies to address future ...
We are given a desktop platform with Java 8 or Java 9 installed and seek to find a way to deploy high-performance Java applications that use Java 3D and/or Jogl without having to run an installer. We are subject to the constraint that the applications be signed and deployed so that they can be run in a trusted environment (i.e., outside of the sandbox). Further, we seek to do this in a way that does not depend on bundling a JRE with our applications, as this makes downloads and installations rat...
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
DX World EXPO, LLC, a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
In this strange new world where more and more power is drawn from business technology, companies are effectively straddling two paths on the road to innovation and transformation into digital enterprises. The first path is the heritage trail – with “legacy” technology forming the background. Here, extant technologies are transformed by core IT teams to provide more API-driven approaches. Legacy systems can restrict companies that are transitioning into digital enterprises. To truly become a lead...
Digital Transformation (DX) is not a "one-size-fits all" strategy. Each organization needs to develop its own unique, long-term DX plan. It must do so by realizing that we now live in a data-driven age, and that technologies such as Cloud Computing, Big Data, the IoT, Cognitive Computing, and Blockchain are only tools. In her general session at 21st Cloud Expo, Rebecca Wanta explained how the strategy must focus on DX and include a commitment from top management to create great IT jobs, monitor ...
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
The IoT Will Grow: In what might be the most obvious prediction of the decade, the IoT will continue to expand next year, with more and more devices coming online every single day. What isn’t so obvious about this prediction: where that growth will occur. The retail, healthcare, and industrial/supply chain industries will likely see the greatest growth. Forrester Research has predicted the IoT will become “the backbone” of customer value as it continues to grow. It is no surprise that retail is ...