urdfparser_py fails on valid new transmission element

[Guillaume W.]

Description: Ubuntu 14.04.3 LTS
Release: 14.04

trusty version of the lib packaged by ROS

ros-indigo-urdfdom-py:
  Installed: 0.3.0-2trusty-20150424-0403-+0000
  Candidate: 0.3.0-2trusty-20150424-0403-+0000
  Version table:
 *** 0.3.0-2trusty-20150424-0403-+0000 0
        400 http://packages.ros.org/ros/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status

Details :

What should happen : urdfparser_py should parse without errors a valid example of a transmission (new type) given in the reference http://wiki.ros.org/urdf/XML/Transmission

What happened : urdfparser_py fails to parse the valid new type of transmission. It requires a hardwareInterface to be there where this is not mandatory (but could exist)

Traceback (most recent call last):
  File "./test_urdf.py", line 48, in <module>
    robot = URDF.from_xml_file(urdf_filename)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/urdf_parser_py/xml_reflection/core.py", line 491, in from_xml_file
    return cls.from_xml_string(xml_string)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/urdf_parser_py/xml_reflection/core.py", line 486, in from_xml_string
    return cls.from_xml(node)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/urdf_parser_py/xml_reflection/core.py", line 481, in from_xml
    return cur_type.from_xml(node)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/urdf_parser_py/xml_reflection/core.py", line 171, in from_xml
    obj.read_xml(node)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/urdf_parser_py/xml_reflection/core.py", line 474, in read_xml
    self.XML_REFL.set_from_xml(self, node)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/urdf_parser_py/xml_reflection/core.py", line 406, in set_from_xml
    element.add_from_xml(obj, child)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/urdf_parser_py/xml_reflection/core.py", line 312, in add_from_xml
    value = self.value_type.from_xml(node)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/urdf_parser_py/xml_reflection/core.py", line 220, in from_xml
    raise Exception(out)
Exception: Could not perform duck-typed parsing.
Value Type: <class 'urdf_parser_py.urdf.Transmission'>
Exception: Required element not set in XML: hardwareInterface

Value Type: <class 'urdf_parser_py.urdf.PR2Transmission'>
Exception: Required attribute not set in XML: type

[Jose Luis Rivero (j-rivero)]

Thanks for the report Guillaume:

This bug tracker is specific for the urdfdom package delivered from Ubuntu. You problem comes probably from ROS packages. I would recommend to report the bug in one of both:

 * Upstream: https://github.com/ros/urdfdom/issues
 * ROS answers: http://answers.ros.org/