rosbridge_server UDP advertise does go through
On my ROS node I am running the 7.14 version of rosbridge_server which has an option to launch so that it uses UDP to talk to clients. This is desirable because I'm interfacing a joystick and I want messages to drop if they don't get through initially.
Every now and then the advertise message from the client doesn't get through. Of course afterwards, all the topic messages fail because rosbridge is not a publisher of that message.
Obviously I can't use TCP to advertise and then UDP to publish joystick messages (teleop).
I can't think of a way to determine if the advertise worked.
1) Can I query rosbridge using UDP to determine what topics its a publisher of?
2) I think it will work if I create a launch file on the ROS node side that - "roslaunch rosbridge_server rosbridge_udp.launch" and then launches a C++ or python script that simply sends rosbridge a JSON message for advertise of messages I'm expecting from a remote client. I believe this will make rosbridge_server a publisher of those topics, so that if the advertise fails, it will still publish the messages correctly.
I appreciate any thoughts on this subject (I was going to say topic :-)).