Newb question, sorry. 12v & 240v

[Nij]

Ok, I understand basic electirics, and have no worries about doing basic wiring (done car wiring and my home in the past).
In 'my van' I want a 12v strip light (possibly 2) and a couple of 'reading'/down lighter (again 12v). When on a campsite I want to hook up to 240v, so I need a transformer for the 12v leisure side. How do I wire this? As surly the transformer will be part of the 12v system also?

Cheers in advance and I know it's going to be a obvious answer,
Nij

[kevtherev]

you can either install some 230 v lighting.. which seems easier to me

or install a hard wired battery charger to charge the batteries up while your hooked up.... to run the lights