industrial_utils: using 'default joint names' when parameter cannot be found is a bad idea

[gavanderhoorn]

In industrial_utils/param_utils::getJointNames(..):

industrial_core/industrial_utils/src/param_utils.cpp

Lines 122 to 129 in 9a0fe17

	// 3) Use default joint-names
	const int NUM_JOINTS = 6; //Most robots have 6 joints
	for (int i=0; i<NUM_JOINTS; ++i)
	{
	std::stringstream tmp;
	tmp << "joint_" << i+1;
	joint_names.push_back(tmp.str());
	}

If either controller_joint_names cannot be found, or the urdf cannot be parsed for joint names, getJointNames(..) returns a set of 'default names'.

This is not a good behaviour: the function should fail if it cannot find any joint names. Making some names up (even though they follow ros-i conventions) and then returning successfully makes for poor reproducibility and complicates debugging.

[Ridhwanluthra]

hi, is this as straightforward as raising as error and returning?

[gavanderhoorn]

@Ridhwanluthra: yes, it should fail:

This is not a good behaviour: the function should fail if it cannot find any joint names.

a suitable message printed using ROS_ERROR(..) and returning false would be good.

[Ridhwanluthra]

cool, fixing this as a part of #wrid18

[Levi-Armstrong]

PR #195 has been merged closing.