does rospy support rosparam update callbacks?

Question

Using rospy/ROS1, I would like a callback when a certain parameter on the ROS1 parameter server is changed.

The closest I could find was get_param_cached which probably has some sort of parameter subscription under the hood, but the details appeared a little cloudy at first sight.

Are rosparam callbacks supported in any rospy APIs? Or do you have a code snippet that can show me how it can be done?

Answer 1

Adding parameter events is a new feature added in ROS 2 for . Part of the parameter design document It's a new feature and not available in ROS 1, either rospy or roscpp.

You will need to do some sort of polling process if you want to monitor for a change.

Answer 2

You have to use dynamic reconfigure to get the events. But it doesn't work for "pure" params, of course.