Gonzalo Ayuso has put together an experiment related to the current OOP structure of PHP - a test working with runtime classes, a structure generated entirely when the script is executed and not predefined in the file.
Last week I was thinking about creation of a new type of classes. PHP classes but created dynamically at run time. When this idea was running through my head I read the following article and I wanted to write something similar. Warning: Probably that it is something totally useless, but I wanted to create a working prototype (and it was fun to do it).
His class is pretty basic - a "Human" object that echoes a "hello world" sort of message via a "hello()" method. He creates the classes inside of different test methods to ensure that his assertions are true. The tests check basic output of the "hello()" method, calling undefined methods, testing inheritance and a test creating and evaluating a dynamic function.
For something more complex, he creates a dynamic class that solves the FizzBuzz kat, a popular programming puzzle. You can find the full code for this and his other examples on github.