Log when a parameter is set

[tylerjw]

Fixes #86

If you build this locally, you can test this by running the example node with debug logging:

ros2 run generate_parameter_library_example test_node --ros-args --params-file src/generate_parameter_library/example/config/implementation.yaml --log-level debug

Then in another terminal change a parameter:

ros2 param set /admittance_controller control.frame.id new_frame

You should see an output like this in the logs:

[DEBUG] [1681944620.098785049] [admittance_controller]: control.frame.id: string = new_frame

[abake48]

tested and lgtm

[tylerjw]

Thank you

[saikishor]

LGTM 👏

[christophfroehlich]

It works, LGTM (except for the missing dash in your instructions ;) --params-file).

I'm just wondering: At the first run, all parameters are listed in the debug output. After changing .frame.id, there is an output line with the change of this parameter but also a subset of other parameters (pid. and gains. structure. I guess all __map - parameters?). Is this intentional?

[tylerjw]

The output that seems extra is intentional, because of how the map parameters work they are reread anytime a parameter changes. The log is printed anytime we read a parameter from ROS including on startup.

[christophfroehlich]

ok, I just saw that at the beginning "all" parameters are written, at run-time only the changed one and the __map parameters.

[tylerjw]

ok, I just saw that at the beginning "all" parameters are written, at run-time only the changed one and the __map parameters.

The reason the map parameters are re-read after any parameter change is it accounts for if you change the key parameter for the map. Re-reading in the library also will declare any parameters that have not been declared and give them default values in the map. Eventually, I hope to fix this by detecting when the key is changed and only re-reading the map parameters then.