Tue 18 May 2010
Object-oriented programming, where is it now? When I was at college we learnt a little about object methods and techniques and when I left I kept reading about them. I remember in the 90s I was incensed that an employer was NOT using object methods appropriately. I EVEN read books about it. You could say I was an object fan-boy. But even I have to admit that OOP didn’t exactly deliver how I expected it would.
You may say that this is a crazy talk and that OOP was/is hugely succesful. Shark-jumping mumbo jumbo. But I might disagree. In fact, sometimes I think the object-baggage we’ve inherited is perhaps as much a hinderance as it is a help. The wake-up call came a few months ago when I realised that almost every piece of code that I’m in contact with these days makes only limited use of object-techniques.
Before I talk about all the ways that OOP is dead let me be clear in the ways that it is not. Because when I say OOP is mostly-dead, I mean it is mostly dead to me. In some areas OOP has delivered in spades. For example in modern OO programming languages nearly all come complete with large object libraries. This much is true. There’s objects in them-thar binaries for sure. But my code? Not so much.
Here’s all the ways I manage NOT to write truly object-oriented software:
The Task is Too Small
Some systems are just too small to develop a complex object class hierarchy for. It would be a waste of time to do so. I estimate these ‘glue’ applications could take up as much as 5% of the total LOC of a large enterprise system. It doesn’t matter whether these glue applications are written in Java or Python or Bash because really they’re just scripts. Scripts are their own thing. I would argue that the less scripts you have in your system the better you designed it because you’re not just duct-taping over the seams.
The Spreadhseets Rule
I would also estimate that some appreciable percentage of your enterprise is run entirely from spreadsheets. Whether you know about it or not. Be it phone book, accounts, trading system or stock inventory. These little beauties contain little or-no object code and are spread far-and-wide. I’ve ranted about the pervasiveness of spreadsheets before, no need to go over it again. However, as far as I know, no-one has implemented the idea of an OO spreadsheet. For that we can all be thankful.
World Wide Wasteland
The create-update-delete application is everywhere. Be it web-or-desktop. These apps are effectively database front-ends that organise the interactions between user and DB in a more user-centric way. For example in .NET there’s not much need nor desire to map your data into real-objects because the data-binding layer is phenomenally powerful at making data-bound apps quickly. There’s no support to help you map from data to objects to Infragistics. Indeed, nor should there be.
Enterprise Business Objects
And this is the bit that makes me a bit sad inside. This is what OO was really meant for. I used to have arguments with business-analysts about the right object model to use and whether a method should exist in a base-class or a derived-class. But now it doesn’t seem like anyone, including me, really cares. It’s just that somewhere along the line it became a little irrelevant. Don’t get me wrong, I work with objects all the time. But they’re not really objects that were sold to me.
They’re just data-holders or as our fathers used to say:
No Methods? No Object
The thing is that to me at least, without methods on your objects there’s literally no object. If objects doesn’t respond to messages they’re just data-records transferring data to some other module that can operate on those records. Usually this other module takes the role of a controller. This, to me, sounds very similar to the programming that our fathers used to-do before C++ and Java 1.1. So much so that it’s tempting to break open my book on JSP.
I think there are two fundamental areas where objects failed to deliver.
Firstly, whilst OO techniques are very flexible in some business domains they aren’t flexible in exactly the right ways for all business domains. I’m thinking particularly about my own area of expertise, which is financial trading systems.
The objects in trading systems tend to be difficult to compose into a meaningful hierarchy that is both expressive and not too abstract. I think ultimately this failing is because financial instruments are actually themselves models of physical events. This means that it’s straight-forward enough to construct an object-model of financial instruments. However as soon as I start innovating with my financial instruments (i.e. construct new financial models from old ones) the original object models tend to break-down pretty fast.
The Technology Stack Sandwich
The second reason is that there are too many different technologies involved in many enterprise-sized solution stacks to make consistent application of OO methods viable. What does that mean? Well this is perhaps a post in itself but essentially as soon as you are using two or more programming languages that must share objects you’re essentially entering an object-desert.
Oh no. Very definitely not. Objects are the only way to make sense of a deep-and-wide library. If the domain allows it they are the only way to go.
The surprise is that objects just didn’t deliver in the way that I thought that they might for me. Which is kind-of interesting because it suggests to me that perhaps me, and a lot of people like me, might benefit from forgetting about objects sometimes and just Programming Like It’s 1995.