Programming Design Patterns: Facade or Not?

Question

Another guy on our team has provided me a library as a jar for his web framework. Let's call this framework "My Friend's Framework".

There's a particular class that I need from his framework. Half of the properties exposed by that class is what I really need for my own application. The other half is not needed. To retrieve the properties of this class you need to do some String manipulation. Since I will be developing my own framework on top of this class, I want to decouple as much as possible the dependency. Maybe in the future another friend of mine will develop a better framework.

So what I did is I generated a facade class for that class. My own framework accesses the properties through my facade class. If "My Friend's Framework" did change, I just have to change one facade class and the rest remains the same. In addition, the String manipulation is done inside the facade class. Also, the facade class only exposes the needed properties. So my own framework just accesses the properties as a normal getter/setter.

However, I had an argument with this guy. He is forcing me to use directly his class since first he won't ever change the implementation of his class. So he tells me that writing a facade class really has no value. But I disagree.

Am I wrong? I do believe I'm right though.

Answer 1

You are not wrong in principle.

You are wrong in that what you are doing is not a facade. Facade is more commonly used in the case where you have an API with a bunch of services. You could use all those services together, but that can get complicated. The pattern is to stand up a single API interface, the facade, which coordinates the service calls into usable, logical actions.

What you are doing is more like the Adaptor pattern. You are adapting his class to your use case by putting another class in front of it.

Note, I am merely pointing out a semantic problem, in practice what you are doing is a good design practice.

Also note that if you don't really plan on intending on updating in the future, you might not need to go thru the trouble. Maybe YAGNI -- you ain't gonna need it.