yeah, but this is something that never needs to be catched it really is a programming error, so I find the test for null unesessary and the possible resulting NPE as more then RTE enough to commincate the coding error.
The problem with the NPE is that you'd need to look at the stacktrace to find what the exception is about, as you get no meaningful message, and the exception might be thrown when you try to dereference the null pointer, which could be far from where getId() is called. What I propose is to throw a RTE when the widget is built. Fail early, if you can.
yep that is the idea completely id should become a final member of the definition as such it needs to be provided during build
it could still be set to null, but would result in a state 'abstract' of the definition meaning it is an a state that will make the createInstance() on it to throw a RTE (IllegalState IMO)
(see wiki page WoodyRefactoring)
this will result in instances that can only point back to definitions that have an id set != null
so getId() on instance level will effectively lead to always returning a non-null
unless we have made a programming error in setting up this chain, this is not a circumstance IMO that requires additional RT checking to generate specific RTE's
+1 sounds ok.
Joerg
