Suppose that you have a couple of transformations, but you do not want to run all of them. The transformation to be executed will depend on conditions only known at runtime. If you have just two transformations, you could explicitly call one or the other in a simple fashion. On the other hand, if you have several transformations or if you do not even know the names of the available transformations, you must take another approach. This recipe shows you how.
Suppose that you want to run one of the three sample transformations described in the introduction. The transformation to run will be different depending on the time of day: