Wizard of X

In part 1, I showed how you can expand the DataObject implementation to allow you to pass a parameter to a method and return the result. It's not a perfectly elegant solution, and it has some limitations, but it's a very solid technique and not at all difficult to implement or maintain. But I kept running into roadblocks. What if I have to compute part of the expression? What if I have to get a value based on another parameterized getter? You can't compute part of an EL expression in your EL. So after some research and experimentation, I created the GetMap. This isn't a new concept - it was developed for JSF 1.1 (which is what XPages is built on) but the rest of the world has moved on to JSF 2.0 and so some of these older techniques can be a little tricky to unearth since this hasn't been an issue in the JSF world for years.

Expression Language is a powerful and useful tool, but it doesn't handle parameterized methods (other than Map.get(Object) and DataObject.getValue(Object)). That means if you need to do anything more complicated than simple data retrieval, you have to jump through some hoops. I'm going help you get started here.