The Vague Concept of Design Patterns
01 Dec 2021
Design patterns are a vague concept that is difficult to grasp. After watching a couple of videos and searching the internet for a while, I finally feel like I have an understanding of what design patterns actually are. To sum it up I would say; design patterns are typical and reusable solutions that can be used for commonly occurring problems in software design. We can say that the patterns are templates that can be customized to solve a specific design problem, and they are best practices for solving common problems. Design patterns originate from Cristopher Alexander, in 1977 he wrote that a design pattern “describes a problem that occurs over and over again in our environment, and then describes the core of the solution to that problem, in such way that you can use this solution a million times over, without ever doing it the same way twice.”
Design patterns become real
When just reading about what design patterns are, it can be quite difficult to understand how they work in practice. For me, the lightbulb went on when I looked at how I had actually used design patterns in my existing projects. I realized that I have used design patterns several times without actually being aware of them. When using Javascript and Meteor a lot of times I have used design patterns without knowing it, since these design patterns are implemented into languages and frameworks. In Javascript, I have used the “Prototype” design pattern when making objects by making a copy of an instance that is prototypical. Now that I know that by doing this I am using this design pattern, I find it even easier to understand the difference between this and making classes in object-oriented languages like C++.
I have also used design patterns in my “Bridging the Gap” project that can be found here. The Observer pattern has an object that maintains a list of its dependents and notifies if there are changes in states. We used Meteor’s own “Observer” pattern “publish-describe” in this project, here the server publishes the collections and the client subscribes to the collection that is needed to render the page. In this project, we have also used design patterns that are specific to the project and not a part of Javascript or Meteor. We used the “Singleton” pattern that provides a global variable. The variable “Profiles” in the “Bridging the gap” project can be viewed as a singleton instance of the ProfilesCollection class.
Easier life using design patterns
When looking at how I have used design patterns I realize that they make coding a lot easier. Instead of needing to come up with new ideas and spending a lot of time trying to figure out how to solve a problem, you can simply find the design pattern that solves your problem. In this way, we can also standardize the way of solving different problems and make it easier to collaborate and maintain code.