S/W Design and Architecture 201911 - Sergio Erick Chávez Flores

Everything that has a beginning must have an end and this book is not the exception. During the course of S/W Design and Architecture, we read the book "Ready Player One" by Ernest Cline and I would like to make an ethical reflection of this book through this blog entry. I would like to start with two quotes:  Morrow wrote in his autobiography that he’d left GSS because ... he felt that the OASIS had evolved into something horrible. “It had become a self-imposed prison for humanity,” he wrote. “A pleasant place for the world to hide from its problems while human civilization slowly collapses, primarily due to neglect.” (p. 120)  (Halliday speaking) “I created the OASIS because I never felt at home in the real world. I didn’t know how to connect with people there. I was afraid, for all of my life. Right up until I knew it was ending. That was when I realized, as terrifying and painful as reality can be, it’s also the only place where you can find true happiness. Beca...

After reading the article "An Introduction to Metaprogramming", there are a few things that I would like to discuss through this blog entry, I would like to start by explaining what is a metaprogram. A metaprogram is a program that generates other programs or parts of a program. So, when we talk about metaprogramming we are talking about writing metaprograms. This kind of programs is useful to eliminate or reduce a tedious or error-prone programming task.  There is a special kind of source generator named quines. A quine is a program that generates a copy of its own source text as its complete output. While other programs (dynamic programs) have the feature to modify some parts of the code during runtime without the need to generate a source code. For our course of Software Design and Architecture, we are using Ruby, which employs the feature to automate common programming task, a clear example is on classes, where you use an attr_accessor method to produce the read/wri...

After reading the article "Microservices", there are a few things that I would like to discuss, we must start first by defining what does a Microservice is. A Microservice architectural style is an approach to developing a single application into modules, each one running its own process and communicating with each other, so when an update is needed the process of implementing the changes is easier.  One interesting thing is the way the Microservice style is compared to the monolithic style where a monolithic application is built as a single unit. A monolithic server is a natural way to approach building such a system. Explaining in a simple way, a monolithic application puts all its functionality into a single process and scales by replicating the monolith into multiple servers; while a microservice architecture puts each element of functionality into separate service and scales it by distributing these services across servers, replicating as needed.  A Microservice...

After watching "The Elephant and the Blind Programmers" and the "4.6 SEM: 4+1 View into Software Architecture" videos, and reading the article "The Elephant and the Blind Programmers" we will discuss the 4+1 View Model, this a model through this blog entry. The 4 + 1 model is used to organize an application according to what every person needs to see, depending on what is the most import things to them and the ones that are not that important. Here we can use the example of the blind programmers and the elephant, every programmer had a different concept of the elephant, the same happens with a team of engineers. The security engineer will see the relevant parts to his needs, so the administrator.  The 4 + 1 model has different views, these are: - Logical View: Class diagram, communication diagram, sequence diagram, state machine diagram, object diagram. Object model: what components will be made and how the will behave.  - Process View: Concur...

The following blog entry will explain the SOLID Principles based on the book Ace the programming interview: 160 questions and answers for success.  SOLID stands for 5 widely accepted principles of object-oriented programming and design, these are the S ingle Responsibility Principle, O pen/Closed Principle, L iskov Substitution Principle, I nterface Segregation Principle, D ependency Inversion Principle. These principles will be explained through this entry.  - Single Responsibility Principle: This principle says that a class should have only one responsibility. It should have only a reason or a class of reasons that cause it to change. This principle might cause a problem for programmers because deciding what a single responsibility means can be a difficulty. A single responsibility refers to a group of related business processes or it could be broken down in its constituent parts, with each part designated as a responsibility. - Open/Closed Principle: This pr...