This week, I decided to look at an article based on the GRASP principles, and found this insightful article from Kamil Grzybek, an experienced designer in the .NET Framework. The GRASP concepts essentially explain how to assign certain responsibilities to different classes within a project. Each principle is derived from a problem, and the principle solves the problem. The first principle, Information Expert, decides which class will take the responsibility for a certain operation. In his example, his Customer class takes the responsibility of compiling an order since it has all the necessary information to do this. The next principle is Creator, which asks the question who creates an object? The answer according to the principle to assign a class to create this object, only if said class is closely related to the object. The next principle Controller decides who is the first object beyond the UI to control a systems operation and delegate information. The fourth and fifth principles are Low Coupling and High Cohesion, which solve the issue of keeping classes independent and to keep them focused on minimal tasks. The sixth principle is Indirection, which solves the issue of avoiding direct coupling between objects. The seventh principle is Polymorphism, which helps control flexibility within the code. The eighth principle, Pure Fabrication, solves the issues of what do to when there is an intermittent task that needs to be completed and avoiding more direct coupling between classes. The final principle, Protected Variants, is argued to be the most important principle. It helps to keep code available to change.
After reading this article, it seems to be a more expanded version of principles and concepts we have learned earlier in the class. Most of the principles within the GRASP lineup are connected to either another set of principles like SOLID, or directly correlate to a specific concept like loose coupling. The main reason I selected this article was the nice use of physical code examples to show off the principles. Throughout the whole article, Kamil used a Customer project that tracked orders. Each concept was show in a different section of the project, which makes it easier to visualize when thinking about how to apply it to code that I create. This article seems more to be for more experienced software designers, which I enjoyed. Learning new concepts with descriptions that are easy to understand can be helpful, but having a more challenging description given to me challenges me to understand the concepts deeper.
To use these principles in the future I must remember a two different ideas.
1.) All aspects of the code need to be individual and loosely related to avoid breaking the code when adding change
2.) It is easier to assign certain tasks to a separate class than to jam pack a single class with all of the functions