Before the 5er (before kids), we had an '03 Eagle Cap camper and that is exactly the way we connected the truck to the camper.
The RV dealer supplied me with a 12' long harness with a male 7-way at each end.
I didn't want to cut a hole in my bed for the connection and the harness laid in the bed nicely.
Our trucks have the additional 4-way tail-light connector if you want to tow a boat or trailer.
Hope this helps,
Louis