As you start to build more complex websites, it is important to organize the data structure efficiently and effectively. HTML 5 added several organizational tags to help provide context to the contained data. In the previous version of HTML, we’d usually use a div tag, with a user created class. However, the issue with that…
Software patterns are a mechanism for capturing domain knowledge in a way that allows it to be reapplied when a new problem is encountered. In some cases, that knowledge is applied to a new problem within the same domain. In other cases, the domain knowledge captured by a pattern can be applied by analogy to…
The state of the class takes on both active and passive qualities. A passive state is simply the current status of an objects attributes. For example: Consider a GPS app. Your position, direction, etc are just attributes of your class, and thus the passive state. An active state is the status of an object that…
In chapter ten, we looked at data and how to identify classes that were needed from Use Cases. In Chapter 11, we look at Information Exchange through Events. An Event is not the data that has been changed, but rather that information has been exchanged between elements. An Event occurs when information that is exchanged:…
Data transformation is often simple like splitting a full name into the first and last, or vice versa. However, sometimes it is more complicated, much more complicated. I once wrote a data converter which had to convert data stored in a file with the size of data store being a certain number of bytes into…
Previously we’ve seen how variables are passed by value. While this works well in many cases, it means that the variable has to be duplicated when it is passed to the function. For large, and/or complicated, variables – like when we start using objects, this can take precious time and resources. However, C++ offers us…
Many times, two or more analysis classes are related to one another in some fashion or another. In UML this is called associations. With Object Oriented code, we often ask if two classes are related or associated through a is-a or has-a type relationship. For example: a car (and object) has a(n) engine (an other…
Operations define the behaviors of the object. While there are lots of different behaviors, they can often be broken down into four main categories. Those that manipulate data often have a set in their function name. Such as setPassword(). Those that check the state of an object usually return a boolean value, and use the…
