Avoiding including abstract class in a general 'bootstrap' file

Question

In my project, say I am instantiating a class named SubClass, which extends an abstract class named AbstractClass. At the top of my files I include a file named bootstrap.inc, which includes AbstractClass in every file. Then, when I need it, I include SubClass which does not contain an include to AbstractClass.

If I include AbstractClass in the files of classes that extend it (such as SubClass), sometimes I am using multiple sub-classes in one file and will get an error. I would rather not include AbstractClass in every file via the bootstrap, since I am not always using it, but cannot think of a way to avoid this.

I have been advised that using include_once() is a sign of poor design, so have avoided that, although it would be one solution.

Is there an alternative method to include_once()?

Answer 1

First off - it's generally a good idea to stick to one class per file. If you're worried about performance, you're being paranoid. In production, you can always turn on APC with stat off.

Secondly - there's nothing wrong with include_once/require_once.

Unless you're going to set up some fancy autoloading magic, just stick to one class per file.

Absent some specific concern (that is, something articulable that you actually understand, not just some rumor you heard), the following pattern is perfectly fine:

<?PHP
require_once 'MyAbstract.class.php';

class Concrete extends MyAbstract {
 //...
}
// end-of-file

Answer 2

PHP's Autoloading mechanism could be ideal for you.

That said, there's nothing wrong with include_once(). What that person talking about a design flaw was probably referring to is that a code flow that includes the same file more than once (thus making include_once() necessary over include() is most likely badly designed.