Comments on: Abstract Classes in AS3

By: Tamazyan Vitaly » Blog Archive » Elegant way to implement Abstract Class is AS3

Sat, 16 Oct 2010 16:38:34 +0000

[...] a good review on the topic which shows different approaches to the problem. My favorite [...]

By: Vit Tam

Vit Tam — Sat, 16 Oct 2010 11:39:00 +0000

Very useful rewievw, thanks a lot! I agree, Object Constructor approach is most elegant

By: Vit Tam

Vit Tam — Sat, 16 Oct 2010 11:39:00 +0000

Very useful rewievw, thanks a lot! I agree, Object Constructor approach is most elegant

By: alec

alec — Wed, 12 Aug 2009 07:07:12 +0000

That’s a fair enough point, and you can definitely not use abstract classes if you prefer. However, sometimes implementations have some duplicated code, and then I would rather abstract commonalities into a common class, just because it reduces duplication and increases coding speed. When the situation isn’t like that, I don’t use abstract classes either! What I do dislike though, is having made my design choice to use them, then having to write error throwing methods because as3 doesn’t support “abstract”. I think it’s all about choice.

By: Anonymous

Anonymous — Wed, 12 Aug 2009 07:07:00 +0000

By: Alan

Alan — Wed, 12 Aug 2009 00:36:51 +0000

When I first began doing OOP, I used the crap out of abstract classes. Now I rearely use them.

In your example I would cut ‘AbstractExample’ and have ‘XMLExample’, ‘BinaryExample’ and ‘SqlliteExample’ implement IExample.

I’m sure that whatever data each concrete class is working on is unique to it’s own implementation and should not be exposed. If your overriding methods in super class, then why bother have the abstract methods?

By: Alan

Alan — Wed, 12 Aug 2009 00:36:00 +0000

When I first began doing OOP, I used the crap out of abstract classes. Now I rearely use them.

In your example I would cut ‘AbstractExample’ and have ‘XMLExample’, ‘BinaryExample’ and ‘SqlliteExample’ implement IExample.

By: alec

alec — Wed, 29 Jul 2009 13:43:24 +0000

For sure Keith, abstract classes are definitely not necessary, just useful.

We have found the most compelling reason for using them comes while designing the model of a large application. We want to use define an interface, then implement the interface with mock objects, then implement the interface via XML, then maybe through a socket connection to a database, and so on…

We find that under a package we have several implementations, all using the same data types and exposing the same interface. We end up with maybe:

interface IExample
class AbstractExample implements IExample
class XMLExample extends AbstractExample
class BinaryExample extends AbstractExample
class SqlliteExample extends AbstractExample

A cleaner architecture would be if the ‘abstract’ AbstractExample class could be really abstract, which we could use instead of the interface.

By: Anonymous

Anonymous — Wed, 29 Jul 2009 13:43:00 +0000

For sure Keith, abstract classes are definitely not necessary, just useful.

We find that under a package we have several implementations, all using the same data types and exposing the same interface. We end up with maybe:

interface IExample
class AbstractExample implements IExample
class XMLExample extends AbstractExample
class BinaryExample extends AbstractExample
class SqlliteExample extends AbstractExample

A cleaner architecture would be if the ‘abstract’ AbstractExample class could be really abstract, which we could use instead of the interface.

By: Keith Peters

Keith Peters — Wed, 29 Jul 2009 13:26:19 +0000

I agree abstract classes would be useful, but question how vital they are. People are obviously building things in ActionScript without them.