[Rock-dev] assumptions in joint_dispatcher

[Jakob Schwendner]

> My use case are motor drivers on a bus.
> Every once in a while they send me a status packet, for which I generate a
> JointState, put it in a base::samples::Joints and send it out the
connection.
> The idea behind this is to not double code and use the logic in the Joint
> dispatcher, to aggregate the single JointStates into a full
> base::samples::Joints.

I see the point. I guess what we have to decide is where to collect the
joints and make sure they are complete. I guess the dispatcher could be a
good place for it. One option would be to flag inputs as dynamic. The
arguments I raised in steffen's comments still hold though. I think it would
be better if the producer would make sure it generates the joint data its
expected to generate (through configuration) and throws when it doesn't.

Jakob