Path: | lib/pluginfactory.rb |
Last Update: | Wed Mar 23 00:01:25 EST 2005 |
This module contains the PluginFactory mixin. Including PluginFactory in your class turns it into a factory for its derivatives, capable of searching for and loading them by name. This is useful when you have an abstract base class which defines an interface and basic functionality for a part of a larger system, and a collection of subclasses which implement the interface for different underlying functionality.
An example of where this might be useful is in a program which talks to a database. To avoid coupling it to a specific database, you use a Driver class which encapsulates your program’s interaction with the database behind a useful interface. Now you can create a concrete implementation of the Driver class for each kind of database you wish to talk to. If you make the base Driver class a PluginFactory, too, you can add new drivers simply by dropping them in a directory and using the Driver’s create method to instantiate them:
The create class method added to your class by PluginFactory searches for your module using