> I have a superclass, let's say it's Dog. Then, I have some extensions of
> Dog, like so:
> Schnauzer extends Dog
> Poodle extends Dog
>
> In the Dog constructor, I want to prevent a Dog from being instanced
> directly, but when I include this line in the
> superclass constructor:
> throw new IllegalOperationError("Class must be instanced through one of Dog's
> subclasses.");
>
> ...all the base class instances throw the error. How best to prevent the
> superclass from being instanced on its own?
AS3 doesn't support abstract classes, only interfaces. You can either
use interfaces instead, or do this:
http://joshblog.net/2007/08/19/enforcing-abstract-classes-at-runtime-in-actionscript-3/
... which is basically what you're doing with a little modification.
You have to have something you can look at during instantiation of the
superclass that's only provided by the subclasses.
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