Being descriptive in code when building objects

Link Listing - July 28, 2007

Christopher Steen — Sun, 29 Jul 2007 03:52:29 GMT

Link Listing - July 28, 2007

re: Being descriptive in code when building objects

Bil Simser — Fri, 27 Jul 2007 19:45:33 GMT

@William: Yes. Can you tell me what's more readable:

Person person = new Person(10, 100, "Abel");

vs.

Person person = PersonBuilder.

StartRecording().

CreateWithFirstName("Abel").

IsOfTheAgeOf(10).

WithNumberOfComputersInHouse(100).

Finish();

Okay, grant you could write:

Person person = new Person();

person.FirstName = "Abel";

person.Age = 10;

person.ComputersInHouse = 100;

However I have to create properties for all of that and if I were to change those properties (maybe to be more descriptive, maybe to remove them) I would have to update all places where I have this code. With the Builder I can a) direct my developers to the Builder if they need to update how Person is created and b) my consuming code is more readable than parameterized constructors. I mean really, did you know what 10 and 100 were in the constructor before you saw the rest of the code? The less code I have to crack open, read, interpret, and understand the better.

To each their own though.

re: Being descriptive in code when building objects

William — Fri, 27 Jul 2007 19:11:00 GMT

I'm sorry. You have got to be joking. You think the Builder class makes instantiating your object MORE readable??

re: Being descriptive in code when building objects

Nate Kohari — Fri, 27 Jul 2007 14:08:35 GMT

I agree that in this case, the fluent interface isn't necessary. But like Bil said, it's not meant for production, and as an example of fluent interface design, it works well.

re: Being descriptive in code when building objects

Jason Dossett — Fri, 27 Jul 2007 12:35:31 GMT

Hey Bil, some people get syntactic sugar, some don't. I'm picturing auto-generated builder classes generated from a class based on custom attributes on public or private properties that let the generator know which helper methods to create and what to name them. I think there is potential there.

re: Being descriptive in code when building objects

Bil Simser — Thu, 26 Jul 2007 23:38:11 GMT

@CodeMan/@Joe: Yes, there are properties and they would read well, but what if I want to pass in one value and set two? In the builder, I can take in a value, set a property and even combine values into readable methods.

@Aaron: Agreed, and really this is just sample code for an idea, it's not meant to be production code.

Guys, the point here (which was obviously missed probably due to my own inability to be expressive) is that you favor readability over creating parameters to a constructor or having to name properties (or even create them). Why must I expose the inner workings of an object to the outside world or maybe have to create properties that sound correct when I don't need to. It's the same as creating a named interface that simply wraps a generic. I would rather use the domain specific language of IVideoGameRental in my domain, than the programmer-speak of IInterface<IVideoGame, IRental>. The less code I have to crack open to actual read in order to gain intent and understanding, the better.

re: Being descriptive in code when building objects

Aaron Jensen — Thu, 26 Jul 2007 23:09:08 GMT

That's a ton of work to put in (unless you generate this...) for what I consider minimal gain... you can always just wait a bit for C# 3.0's anonymous constructors.

Oh, and to clean things up a bit you may consider ditching StartRecording/Finish and adding an implicit operator VideoGame to VideoGameBuilder.

re: Being descriptive in code when building objects

Joe Chung — Thu, 26 Jul 2007 22:41:19 GMT

Umm, yeah, there are also these things called "properties."

re: Being descriptive in code when building objects

CodeMan — Thu, 26 Jul 2007 21:45:00 GMT

Your class has a default constructor why not just set the individual properties your self. The game builder appears to provide no value, other the the ability to chain the calls to gather what is the point.