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Message:

Creation of objects from an inheritance hierarchy

Posted by Kumar on January 08, 2001 at 11:17 PM

Hello,
I am not sure if this is the right forum to address this.

I have designed a class hierarchy which was pretty straight-forward for my application.
For eg, there's a base(abstract) class A. Class B and Class C are currently derived from A. One of the major objectives of this inheritance hierarchy is to plug in new classes for new requirements, for eg, Class D can be plugged in to be derived from Class A for additional requirements.
This fits well into my plan until now!
Objects of class B and C are currently instantiated based on a data format. If the data format starts with a specific pattern, B is created, and there's a specific pattern for C as well.
I have currently hard-coded it.
if (pattern="abx", new B());
else if (pattern = "xyc" new C());
Obviously, if I have a new class D, the plug-in is not seamless, as I still have to write code to create an object D.
Is there a simple design pattern (for a relatively new OO team) to solve this problem.
Thanks
Kumar