Software Constr – Blog Three

APIs are something we come across a lot, especially the openapi.yaml file we look at for the Microservices Activities in class. So, I wanted to make a note for myself on what APIs are, the benefits, and the different types.

Firstly, what is an API? API stands for Application Programming Interface and it’s a mechanism that helps two software components communicate by the use of definitions and protocols. “For example, the weather bureau’s software system contains daily weather data. The weather app on your phone “talks” to this system via APIs and shows you daily weather updates on your phone.” And there are four different ways an API works: SOAP, RPC, Websocket, and REST.

The SOAP API is short for Simple Object Access Protocol API and it works with the client and server exchanging messages and other the use of XML. Remote Procedure Calls, RPC, APIs has the client complete a procedure on the server in which the said server would send back an output. Websocket APIs use JSON objects to pass the data being used and supports a two-way communication between the client apps and the server.

REST API is one we had just worked with in class and had homework on. It’s the most popular since it’s flexible and has the client send a request as data to the server which starts to use internal functions to return outputs back to the client. REST stands for Representational State Transfer that defines functions such as GET, PUT, DELETE, etc., all of which we have seen in the openapi.yaml file.

The REST API has four main benefits: integration, innovation, expansion, and ease of maintenance. Integration is used to increase development speed since the functionalities won’t have to be made from scratch because of the fact that APIs are used to integrate new applications with existing software systems.

Innovation is where industries can change with new arrivals of apps entirely since they can make changes without having to rewrite the entire code at the API level. “Businesses need to respond quickly and support the rapid deployment of innovative services.”

Expansion is something where it’s a unique chance for businesses to meet the needs of their customers across so many different platforms. “For example, maps API allows map information integration via websites, Android,iOS, etc. Any business can give similar access to their internal databases by using free or paid APIs.”

And finally, ease of maintenance. REST APIs act as a sort of gateway between systems. They each make changes internally so that the API isn’t impacted and in response? “Any future code changes by one party do not impact the other party.”

Source: https://aws.amazon.com/what-is/api/

From the blog CS@Worcester – The Progress of Allana R by Allana Richardson and used with permission of the author. All other rights reserved by the author.

For this quarter’s blog, I decided to research more into the book Clean Code by Robert C. Martin and found a blog discussing the good, the bad, and the ugly regarding the book. I chose this article because we have spent the last few classes working through POGILs related to the book. The author writes about how Clean Code has had its positive and negative impact on software development. For new programmers, the author highlights useful practices that are good for new software developers, such as good naming techniques, not repeating your code, and having functions only do one thing. On the other side, the author describes how the age of the book and its dated techniques can be considered obsolete. Clean Code was written over twenty years ago and is heavily focused on Java programming and outdated extensions that “[limit] the applicability for modern programming practices.” Another criticism by the author is that applying the rules of the book all the time can result in harmful code, such as excessive abstraction and code that is harder to maintain over time. The author argues that programmers should learn when these rules should be broken and apply them on a case by case basis.

This article was certainly helpful to give a further opinion on Clean Code and its subject matter. After going through the Clean Code POGILs in class, I had learned many things that I was not previously taught about programming. They were helpful to correct some bad practices that I was guilty of, such as commenting in place of poorly written code. However, some topics, such as the levels of abstraction or how to use classes and methods properly were initially confusing to me. It seems like the author also expresses similar frustrations in regard to these things. The author of the article describes any of the things from the book can be described in one phrase: “it depends.” Overall though, I felt it necessary to dive deeper into Clean Code for my own benefit. Even though I do not plan on pursuing a career in software development, many of these rules and structures can be applied to other disciplines within computer science and information related fields. When the time comes for me to work on a personal project or something needed for my career, I feel better equipped to handle such a task knowing what I know now. Even if some of the advice is dated, most of it can still be applied and result in better software development.

Original blog post: https://gerlacdt.github.io/blog/posts/clean_code/

From the blog CS@Worcester – zach goddard by Zach Goddard and used with permission of the author. All other rights reserved by the author.

As a software developer version control you will undoubtedly run into version control of any projects which you are working on. Eventually a developer will have to fix bugs or add a feature to a product. In order to learn more about version control there is no better website to learn from than Github.

What is Version Control?

Github gives an amazing allegory: Imagine you’re a violinist in a 100-piece orchestra, but you and the other musicians can’t see the conductor or hear one another. Instead of synchronized instruments playing music, the result is just noise.

Version control is a tool used to prevent this noise from happening. It helps streamline development, keep track of any changes, and allow for upscaling of projects.

Version Control tool factors

Version control may not be necessary depending on the scale of your project, however most of the time it is useful to have it set up. Some of the factors of deciding to use version control include:

• Scalability: Large projects with many developers and files benefit from VC
• Ease of Use: User friendly UI helps manage learning curves and adoption.
• Collaboration features: Supporting multiple contributors and communication between them.
• Integration with existing tools: Using tools everyone already has access to.
• Supports branching: Ability for developers to work on different parts of development benefits a project greatly.

Common Version Control pplications

• Git: Git is an open-source distributed version control tool preferred by developers for its speed, flexibility, and because contributors can work on the same codebase simultaneously.
• Subversion (SVN): Subversion is a centralized version control tool used by enterprise teams and is known for its speed and scalability.
• Azure DevOps Server: Previously known as Microsoft Team Foundation Server (TFS), Azure DevOps Server is a set of modern development services, a centralized version control, and reporting system hosted on-premises.
• Mercurial: Like Git in scalability and flexibility, Mercurial is a distributed version control system.
• Perforce: Used in large-scale software development projects, Perforce is a centralized version control system valued for its simplicity and ease of use.

Final thoughts

Every developer has at one point heard of Git, and without a doubt it may be one of the best developer tool ever invented. I have prior experience using version control but this research was an important refresher to learn from. If you wish to learn directly from Github you can read the article this blog was inspired by here.

From the blog CS@Worcester – Petraq Mele blog posts by Petraq Mele and used with permission of the author. All other rights reserved by the author.

Sometimes when a program undergoes consistent updates it can get messy, in cases like this it can be useful to refactor it. I’ve had a few experienced cleaning a program however I have never refactored an entire program. The developers over at refactoring guru luckily have a website dedicated to this subject.

Purpose for refactoring

When you refactor a program you are fighting something they call technical debt and create clean code. With clean code comes a few benefits including:

• Obvious for other programmers
• Doesn’t contain duplicate code
• Minimal number of classes and other moving parts
• Passing of all tests
• Easier and cheaper to maintain

What is technical debt?

“Technical debt” as a metaphor was originally suggested by Ward Cunningham using bank loans as an example.

You can make purchases faster If you get a loan from a bank however now on top of principal you have interest. and with time you can rack up so much interest that the amount of interest exceeds your total income, making full repayment impossible.

The same concept can be applied to code. Speeding up without testing new features will gradually slow your progress.

Some causes of technical debt include:

• Business pressure
• Lack of understanding the consequence
• Failing to combat the strict coherence of components
• Lack of tests, documentation, communication.
• Long-term simultaneous development in several branches
• Delayed refactoring
• Incompetence

So when should one refactor?

Refactoring guru comes up with a few instances on when to refactor.

• Rule of three:
  • When doing something for the first time, just get it done.
  • When doing something similar for the second time, cringe at having to repeat but do the same thing anyway.
  • When doing something for the third time, start refactoring.
• Adding a feature:
  • If you have to deal with someone else’s dirty code, try refactoring it first; Easier for future features.
• Fixing a bug:
  • Clean the code and errors will discover themselves
• Code reviews:
  • Last chance to tidy up the code
  • Best to perform these reviews in pair with an author

We know when, but how?

Refactoring is done via a series of small changes, each making the existing code slightly better while leaving the program in working order.

Here is a checklist on refactoring done the right way:

• The code is cleaner
• There should not be new functionality
• All existing tests pass

Final Thoughts:

Overall, I found this website on refactoring to be really informative and would recommend refactoring guru as a starting point. The most important thing that I got out of this is that developers should always try to write clean code or clean code as its undergoing development. Unfortunately sometimes software development can be very time containing and its not always possible which is why refactoring is important.

From the blog Petraq Mele blog posts by Petraq Mele and used with permission of the author. All other rights reserved by the author.

I decided to write this self-directed blog entry on an article I found regarding information and differences between Agile and Scrum, two topics we have recently been covering in class. I sought to learn more about these two topics, as I was not entirely confident in my understanding of them. I unfortunately was absent due to an illness on the day we covered the Agile methodology in class, so in order to get a better understanding on the topic, I went through the activity and learned more about it on my own time. This article summarizes what Agile and Scrum are, their differences, the core Agile values and principles, the basics of Scrum, and when and how they should be utilized. This was quite a thorough read and was very informative to reinforce what I had learned from the class. One thing that I did not immediately connect from class was that Scrum was based on the Agile philosophies. As best said in the article, Agile is the guiding principles to shape how you work, Scrum gives a structured playbook to follow.

Though I do not plan to go into software development as a career path, I think this is still a beneficial way to learn quality teamwork and collaboration. Regardless of concentration or field of study, computer science and information systems related disciplines require efficient teamwork and collaboration. Working professionally in the field for four years now, there has never been a project or major task that involved no one besides myself. I always had to work with different teams to accomplish the final goal that was needed. Learning this framework could be very beneficial for me moving forward so I can apply it to my future professional projects. Having better tools almost always leads to a better job done, and I always strive to improve and better myself as a technology professional.

One discovery made from this article is that there are other common implementations of Agile outside of Scrum. One of these, I recognized from my professional experience, as my current organization requires all full-time staff to participate in Lean training. I was not aware that Lean training, which according to the article, “aims to eliminate waste and maximize customer value by focusing on efficiency and continuous improvement,” was an extension of the Agile methodology. This is critical, especially in the healthcare environment that I work in. It is an everchanging field and an environment that can change drastically within a matter of seconds. Though I am not a full-time employee and have yet to participate in that training, I will participate in it once I resume full-time work permanently at the end of December 2025.

ZG

The link to the blog post: https://monday.com/blog/rnd/agile-vs-scrum/

From the blog CS@Worcester – zach goddard by Zach Goddard and used with permission of the author. All other rights reserved by the author.

Hello everyone, today I will be talking about the Principle of Least Knowledge (AKA Law of Demeter). When first looking into this topic I was unsure of exactly what this was and how it would be applied to programming. When doing my research I found the Khouri College of Computer Sciences at North Eastern University had a page dedicated to this topic, where this law was first introduced.

General Formulation

The LoD is essentially a simple style rule for designing object oriented systems.

“Only talk to your immediate friends” is the motto. 

Professor Leiberherr, the author, states a formulation of “Each unit should have only limited knowledge about other units: only units “closely” related to the current unit.” Its main motivation is to control information overload thus helping memory management as each item is closely related.

You can informally summarize the Law with these three formulations:

• Each method can only send messages to a limited set of objects, namely to the argument objects and to the immediate subparts of the class to which the method is attached.
• Each method is “dependent” on a limited set of objects (organize dependencies)
• Each method “collaborates” with a limited set of objects (organize collaborations)

To formulate the Law we can choose from the following independent possibilities:

• Object/Class
  • Class formulation is intended to be compile-time
  • Object formulation is intended to be followed conceptually
• Messages/Generic functions/Methods
• Weak/Strong
  • If we interpret it as all instance variables, including the inherited ones, we get the weak form of the Law. If we exclude the inherited instance variables, we get the strong form of the Law.

Benefits

In a paper written by Leiberherr, there are a couple facts stated for the benefits:

• If the weak or strong LoD is followed and if class A’s protocol is renamed, then at most the preferred client methods of A and A’s subclasses require modification.
• If the weak or strong LoD is followed and if the protocol of class A changes, then only preferred client methods of A and its subclasses need to be modified and only methods in the set of potential preferred clients of A and its subclasses need to be added
• There’s even more benefits highlighted in the paper pertaining to limiting information overload.

Final Thoughts:

Prior to this webpage I knew nothing about this law/principle, however I now understand that it is a fairly useful rule or its respective use case. The law teaches you a way to program Classes, Inheritance, Abstraction, and a few other techniques. Infact There is so much more depth to this that I cant even fully fit it into this blog post. I would highly recommend you check out this page as It contains all the information you need along with sources to learn this.

From the blog Petraq Mele blog posts by Petraq Mele and used with permission of the author. All other rights reserved by the author.

By Petraq Mele

Hello again to those reading this blog, this time I want to talk about an extremely topic relevant in the programming atmosphere, that being a concept known as SOLID. I managed to find a great section written by Manoj Phandis on these principles.

SOLID is an acronym of five OOP design principles designed to help make it more understandable, flexible, and maintainable.

What are the main 5 design principles?

SINGLE RESPONSIBILITY PRINCIPLE: This principle states a class should have one, and only one, reason to change. Lets take an Animal class example, as opposed to the animal class having a sound and feed parameter, separate those responsibilities into separate classes.

Some benefits include:

• more readable, that is easier to understand
• less error prone
• more robust
• better testable
• better maintainable and extendable
• maximizes the cohesion of classes.

OPEN CLOSED PRINCIPLE: “Open for extension” means the behavior of a module can be extended. “Closed for extension” means when we are adding/extending a modules behavior it should not result in changes to a modules source or binary code.

An example Manoj gives is a credit card company wanting to introduce a new preferred credit card product with double reward points. Instead of using conditionals, you create an extension via implementation inheritance or interface abstraction.

LISKOV SUBSTITUTION PRINCIPLE: LSP states functions that use references to base classes must be able to use objects of the derived class without knowing it. For LSP compliance we need to follow some rules that can be categorized into 2 groups:

• Contract rules
  • Preconditions cannot be strengthened or weakened in a subtype
  • Invariants must be maintained
• Variance rules
  • There must be contra-variance of the method argument in the subtype & be covariance of the return type in the subtype
  • No new exceptions can be thrown by the subtype unless they are part of the existing exception hierarchy.

INTERFACE SEGREGATION PRINCIPLE: Clients should not be forced to depend on methods they do not use. Interface segregation violations result in classes depending on things they don’t need & an increase of coupling and reduced flexibility/maintainability.

Tips to follow:

• Prefer small, cohesive interfaces to “fat” interfaces
• Creating smaller interfaces with just what we need
• Have the fat interface implement your new interface.
• Dependency of one class to another should depend on the smallest possible interface.

DEPENDENCY INVERSION PRINCIPLE: This principle has two parts. The first part says high-level modules should not depend on low-level modules. Both should depend on abstractions. The second part says Abstractions should not depend on details. Details should depend on abstractions.

Part one example:

Part two example:

Final thoughts:

Overall these principles are very useful when it comes to object-oriented software development. I learned quite a good amount and I want to thank Manoj Phandis for their amazing outline of the SOLID principles, I would advise you to check them out in his website incase you’re interested in learning more.

From the blog Petraq Mele blog posts by Petraq Mele and used with permission of the author. All other rights reserved by the author.