Action-Domain-Responder

This post is part of The Software Architecture Chronicles, a series of posts about Software Architecture. In them, I write about what I’ve learned about Software Architecture, how I think of it, and how I use that knowledge. The contents of this post might make more sense if you read the previous posts in this series.

MVC was created in 1979, in a context of desktop applications with CLI user interfaces and it implied that the UI would be changed automatically if there were changes in the database, caused by some factor external to the user. The same pattern was perfectly usable later on desktop applications with a GUI.

However, its usage in web applications has always been an adaptation because most web applications don’t change the UI as a consequence of changes that happen in the server side, there is always a call from the UI asking the server side for an update of the screen.

I have talked about variants of the MVC pattern before, this post is about another variant: Action-Domain-Responder, created by Paul M. Jones. Continue reading “Action-Domain-Responder”

Resource-Method-Representation

This post is part of The Software Architecture Chronicles, a series of posts about Software Architecture. In them, I write about what I’ve learned about Software Architecture, how I think of it, and how I use that knowledge. The contents of this post might make more sense if you read the previous posts in this series.

MVC was created in 1979, in a context of desktop applications with CLI user interfaces and it implied that the UI would be changed automatically if there were changes in the database, caused by some factor external to the user. The same pattern was perfectly usable later on desktop applications with a GUI.

However, its usage in web applications has always been an adaptation because most web applications don’t change the UI as a consequence of changes that happen in the server side, there is always a call from the UI asking the server side for an update of the screen.

I have talked about variants of the MVC pattern before, this post is about another variant: Resource-Method-Representation.

I feel the need to talk about it, not because I find it a key pattern in my practice but because of the misconception that it is the same as the ADR pattern, of which I will write about soon. Continue reading “Resource-Method-Representation”

“Model 1” & “Model 2”

This post is part of The Software Architecture Chronicles, a series of posts about Software Architecture. In them, I write about what I’ve learned about Software Architecture, how I think of it, and how I use that knowledge. The contents of this post might make more sense if you read the previous posts in this series.

Java Server Pages (JSP) is a technology, a scripting language comparable to PHP, ASP, or even Python, that is used to create server-side pages interpreted by the JVM and which can use Java objects.

The first JSP specifications, published in 1998 by Sun Microsystems, defined two ways of structuring an application so that the presentation logic would be decoupled from the business logic, and even the use cases, in an HTTP request/response paradigm.

Some consider these “Model 1” and “Model 2” the first tries at adapting the MVC pattern, originally intended for a context of desktop software development, to the web HTTP request/response paradigm. Continue reading ““Model 1” & “Model 2””

EBI Architecture

This post is part of The Software Architecture Chronicles, a series of posts about Software Architecture. In them, I write about what I’ve learned on Software Architecture, how I think of it, and how I use that knowledge. The contents of this post might make more sense if you read the previous posts in this series.

The Entity-Boundary-Interactor (EBI) Architecture has been made known by Robert C. Martin in his talks about Clean Architecture (of which I will talk in a later post).

However, this pattern was published by Ivar Jacobson back in 1992, in his book Object-Oriented Software Engineering: A use case driven approach. At the time, Jacobson actually called it Entity-Interface-Control, but the name was changed so that “Interface” would not be confused with the “Interface” language construct (which some languages don’t even have) nor with “User Interface”, and “Control” would not be confused with the MVC Controller.

Continue reading “EBI Architecture”

MVC and its alternatives

This post is part of The Software Architecture Chronicles, a series of posts about Software Architecture. In them, I write about what I’ve learned about Software Architecture, how I think of it, and how I use that knowledge. The contents of this post might make more sense if you read the previous posts in this series.

Creating maintainable applications has always been the real long-term challenge of building applications.

Not long ago, I worked for a company whose core business application was a SaaS platform, used by a few thousands of client companies. That crucial application was three years old and had code files with HTML, CSS, business logic and SQL mixed up. Of course, two years after being released, the company decided to rebuild it from scratch. Although these situations still happen, today many of us know these practices are wrong and know how to avoid them.

However, back in the 1970s, mixing responsibilities was the common practice and people were still trying to discover how to do it better. As application complexity grew, making changes to the UI would inevitably imply changes to the business logic as well, increasing the complexity of the changes, the time spent to do those changes and the likelihood of bugs (because there would be more code changed).

MCV came into play to solve those problems, by promoting “separation of concerns” between front-end and back-end.

Continue reading “MVC and its alternatives”

Web development with PHP

A PHP tutorial. I advice the visualization of all videos because along the playlist I make some “mistakes” on purpose, that later they become “problems” and need to be fixed. This way I can show why we should do it this or that way. Until now I’ve only created series nbr 7, explaining how to use PHP to connect to a database using PDO and how to structure an application using the MVC design pattern.

You can download the source code here.

  • Web Dev: 01 – PHP
    • Creating the database
    • Creating the SVN repository and the project in Eclipse
    • Connecting to the database
    • Using SELECT
    • Using INSERT
    • What is the MVC design pattern and how to use it
    • Using UPDATE
    • Using DELETE
    • Using prepared statements
    • Using transactions
    • Wraping up the project with CSS and DIVs