Newbie RV Question

Folks-
Just trying to come up to speed on the basics before I configure my system, sorry for my ignorance!
I have a 24ft Lance travel trailer that I want to add solar to. None of the wiring diagrams I have seen so far include the charging system in the trailer or the connections to the tow vehicle and its charging system. The solar system is always shown in it's own world.
If I install a charge controller and connect it to the battery (ies) mounted on the trailer is there any potential for damage to either the 120-12v converter/charger in the trailer or the charging system/battery in the tow vehicle?
The output of the charge controller will be connected to the battery and the trailer's 120-12v converter/charger will be connected to the battery at the same time. Seems like the outputs of both charging systems will be connected to one another. 
Am I missing something?

When people retrofit solar to an RV do they simply connect the charge controller to the battery terminals and all is good?
Thanks in advance,
Stan

The typical RV install: A disconnect on the battery so the RV idle/parasite loads don't discharge the batts.
Some folks keep the brake away always connected, ie the disconnect does not disconnect the brake away.
Then ya add solar with the controller close to the battery, it does not get disconnected either.

The solar never gets disconnected as it plays well with all other charging sources.

Most controllers warns against disconnecting the batt/controller before the panels and the reverse for connecting, ie the batt gets connected to the controller then the panels.

Having something in line from the panels like a fuse or breaker to allow for disconnecting is a good idea.

Same for the batt to controller, a pullable fuse or a circuit breaker that has a switch.

So in short YES, sinply connect the charge controller to the batt terminals and then connect the panels and all is great!
Solar is a good maintainer for storage!