If you haven’t had the opportunity to work on a really big project, naming is probably not on your top list of programming best practices. And you are certainly going to regret that when your project grows.
Of course, everybody, including good old Scott, knows that CUST signifies CUSTOMER and DEPT signifies DEPARTMENT. And statistically speaking, the chances for these abreviations to mean something else is very small – as long as your domain model is, also, quite small. But, when the number of classes in the domain is in the hundreds or even in the thousands you’ll suddenly find out that CUST may signify CUSTOMS (as in ‘Customs Tax’), CUSTOMIZATION or even CUSTARD. I am working right now in the development team of an ERP for agro-food industry and wouldn’t be amazed to see such an attribute name. I’ve seen worst, some details of the implemented business model are a total blasphemy for human logic and common sense.Anyway, the problem is even worse in these big projects because domain model classes are not written by hand, they are generated. While this is hardly a novelty for you (please don’t laugh in the audience), it also means that analysts are composing the datamodel, then classes/mappings/SQL schema/docs are generated, finally programmers will write the business logic and infrastructure integration using the generated artifacts. Names are usually propagated all along the generation chain. And when a programmer finds ‘Cust’ in the name of an attribute, how does she know it’s a ‘Customer’ and not some ‘Custard’ ? Especially when the documentation is scarce and the author analyst is in a well-deserved six-months sabbatical in Anctarctica. Hence, the need for standardization. This is usually done via a dictionary containing the abbreviations and their meaning(s). The rule is very simple : every word in the datamodel must be composed of abbreviations from the dictionary. Some programmers might argue that there is no need for abbreviations and full words are ok – lovely code such as ‘.getSecondaryBillingAddressForService(currentBill.getBillableServicesList(i).get(currentService)).getStreet().getName()’. This is perfectly understandable, however let’s not forget that some databases (Oracle, Sap DB, etc.) have issues with table and column names longer than 32 characters, like for instance refusing to create it in the first place. Which is mildly bothersome if you use a relational database*. And the golden rules of domain model naming are : - Be a pedantic bastard. Don’t just throw the dictionary in the wild and tell people ‘yeah, pleease follow this standard’. Make automatic checking on every piece of datamodel feeding the code generator. The automatic checking should be done at each save operation if possible. I have implemented this inside an Eclipse plugin used by the project analysts: when hitting save on an entity containing invalid names, a window will immediately pop up and inform about the errors. Don’t just display the errors, but completely forbid saving if the entity has naming issues. This will keep the naming absolutely pristine, however the analysts might be tempted to create a lynch mob. Do not give up. - Avoid synonyms, plurals, etc. This is a software product, not a grammar contest. - Throw some stats on the mail from time to time to tell how well the model is named. People will like that. My current gig involves, among other interesting stuff, managing the naming tools in the various Java projects that we are developing. Unfortunately, the naming rules were not really enforced (they had no pedantic bastards before me ?), so the domain model is only partially compliant. Hence, I’m in the midst of developing tools for automatic renaming of model and the new code is going to disrupt the activity for a while (thank God for autocompletion features in modern IDE’s !). Things would have been much smoother if the naming was enforced from the beginning. I think there is not such thing as ‘too late’ to put naming in order in a big project. And it’ll absolutely be done, because there’s very strong managerial support for this kind of tasks (main company shareholder and CEO is a former programmer himself, as well as a quality buff – ‘when time permits’™).
Unfortunately, I had to allow some ‘non-compliant’ islands of code in the modules which are already deployed at customers. But, have no false hopes, sooner or later I’m gonna get that code too. I’m a pedantic bastard, and proud of it.* Now, if you’re using a wanabee storage solution like Prevayler to store gigabytes of business data (or more!), you have much bigger problems than naming. Please stop reading this article and do something about it.