Always Start with the Use Cases

You usually come into any project with somewhat of an idea of what you want the thing to do. The first step, therefore, is to get these ideas down on paper. This process can encompass a mission statement, feature list, or other textual description of what you want to get done. We are in the brainstorming phase here, so anything you write is good. Let the ideas flow.

Now when you are ready to sit down and actually begin work (making sure your coffee cup is filled first) the first step should be use case diagramming. We are still in the brainstorming phase at this point, but use cases make the application begin to take shape, with early definitions of actual application components emerging.

Many of the use cases will be obvious. Some will become evident once the more obvious ones are defined. For use cases, there will certainly be “view available quizzes”, “take quiz” and of course some sort of authentication / log in behavior.

The initial data model can be developed in parallel with the use cases. Remember, both of these models will evolve throughout the life of the project. We are not doing big upfront design here, just enough architecture to get going. But some formal design is always a good idea.

As you go through the use case modeling, keep a note of the domain objects that you start describing. Start building your domain / class model now as well. Some of these will be obvious. In my cases, things like Quiz, Answer, Question, and of course the always present object User, were things I didn’t need to think much about. But the relationships between the two are not obvious. Is user related to quiz, quiz to question, or is there something more complex going on.

As soon as a few main uses cases are defined, it is time to jump into coding. Besides the fact that this is what I like to do, early coding will help you solve early problems and answer unknowns related to new technologies. You just want to make sure you are on the right track. This is called the vertical slice approach, where you build out a piece of functionality, generally a couple of use cases, from start to finish (from the web page to the database, the full stack). Plus it is always nice to have a working application to show. I won’t go into a full discussion of this topic. Just see any of the Agile literature for more information.

The quiz application is not yet an earth shattering innovation (but I do have a few things planned that could very well be). However, one goal is to implement the latest best practices in web application development. As such, I finally have the luxury to take the time and do it right. Of course, there are time pressures for this one as well, there always are. Even if there aren’t any dictated timelines, technology will eventually move ahead, you can’t stop that, and you will always be chasing the latest and greatest technology and practices.

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