Should you beware of the utility base class?
time to read 2 min | 247 words

What do you think about a base class that doesn’t offer any business value to an object, but provide services? By that I mean a base class that takes care of persistence, validation, etc.

I just run into a situation where I’ve such a class, but I don’t want some of my classes to use it. The problem is that this happens in the middle of the hierarchy. Here is the scenario:

- Rule – Persisted to database

 - Built-in Rule – Not persisted to database

 - Lots of Rules – Persisted to database

 

Rule inherits from a base class that handles the persistence. Most of the rules are persisted, but the built in ones always exist. What I needed was a way to do multiply inheritance, so I could have this hierarchy:

 

- Rule – Not persisted, provide common interface and services

 - Built-in Rules – Not persisted.

 - Persisted Rule – Inherits from Rule and the persistence class

   - Lots of rules

 

You can’t do that in .Net (which is a shame).

Right now I’ve a situation where a built in rule looks like it can be persisted, which I don’t want to happen. Any suggestions?

 

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