you're welcome and exactly !
In principle we can do this with a model - as said before.
In cases we don't want to program this - or we can't - my proposal together with sql datasources is the only way I can see in the moment to get this working. Also a view in a database could solve this. Ugly programming.
By the way:
1. I solved the externalPainter - I hope - to be used with bands. See issue #374 (#371 for a minor bug, but it took me long to find it)
2. are you interested in commercial marketing ? This should not be discussed here. I compared really a lot of tools and there are some advantages.
bye for now