[Joint State Broadcaster] Publish the joint_states of joints present in the URDF

[saikishor]

Right now, when no joints parameter is set, it publishes all the entities with the position, velocity and effort interfaces, and the MoveIt and other plugins do not like that information and continuously spam with the warning logs, we have like 50MB of logs for 6 min run.

This PR tries to publish the joint_states of the joints that are within the URDF when no joints or interface params are set.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.39%. Comparing base (298df4b) to head (baf8b86).
Report is 1 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1233      +/-   ##
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+ Coverage   80.23%   80.39%   +0.15%     
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  Files         105      105              
  Lines        9268     9333      +65     
  Branches      817      818       +1     
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+ Hits         7436     7503      +67     
+ Misses       1557     1556       -1     
+ Partials      275      274       -1     

Flag	Coverage Δ
unittests	80.39% <100.00%> (+0.15%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
..._state_broadcaster/src/joint_state_broadcaster.cpp	87.17% <100.00%> (+1.74%)	⬆️
..._broadcaster/test/test_joint_state_broadcaster.cpp	95.37% <100.00%> (+1.52%)	⬆️

... and 1 file with indirect coverage changes

[christophfroehlich]

JSB uses all joints defined in the ros2_control tag. with URDF you don't mean the ros2_control tag but the URDF-Model itself?
How can that be that someone has joints in the tag not being in the URDF model? RM does not init successfully anyways?

[saikishor]

JSB uses all joints defined in the ros2_control tag. with URDF you don't mean the ros2_control tag but the URDF-Model itself?
How can that be that someone has joints in the tag not being in the URDF model? RM does not init successfully anyways?

You can have state interfaces from the actuators before transmission and after transmission are the joints so they are pretty different

[christophfroehlich]

I was not aware of the problem before. But adding gpio or sensor types with interfaces called position

<gpio name="my_gpio">
  <command_interface name="position"/>
  <state_interface name="position">
    <param name="initial_value">1.0</param>
  </state_interface>
</gpio>

lets the JSB publish them.

As we currently don't have information about the type of the handles in the controllers (they exist only in the HardwareInfo class) we have to parse that again from the URDF. --> this PR is a straight forward solution of implementing that.