Draft: Foxy-devel

[relffok]

Hi there,

I started porting this to foxy a while ago. I also needed to port the tests, so there is no qualified statement whether this works as intended or not. I use it for the mir_bridge (see DFKI-NI/mir_robot#96) and it does it's job.
I'm sure there will be some issues (there are 2 failures I could not fix so far but unfortunately ported this a while ago and forgot about the PR), so feedback would be great on this!

Also since I renamed the package from rospy_message_converter to rclpy_message_converter I think a little bit of git history went missing. Sorry about that.

[mintar]

Thanks for the PR! I'll look into it as soon as I find the time!

[rcywongaa]

FWIW, this is also working on galactic 👍

        goal_msg.trajectory.points = [
          message_converter.convert_dictionary_to_ros_message('trajectory_msgs/JointTrajectoryPoint',
          {
            "positions": [0.2, 0.0, 0.0, 0.0, 0.0, 0.0],
            "time_from_start": [1, 0]
          })
        ]

though this doesn't work

        goal_msg.trajectory.points = [
          message_converter.convert_dictionary_to_ros_message('trajectory_msgs/JointTrajectoryPoint',
          {
            "positions": [0.2, 0.0, 0.0, 0.0, 0.0, 0.0],
            "time_from_start": Duration(seconds=1)
          })
        ]

(http://docs.ros.org/en/api/trajectory_msgs/html/msg/JointTrajectoryPoint.html)

Thanks a lot for doing this! Hope this gets merged soon! 💪

[mintar]

this doesn't work
"time_from_start": Duration(seconds=1)

That's not supposed to work. convert_dictionary_to_ros_message converts a JSON-like dictionary to a ROS message, and there should be only basic datatypes (string, int, float, ...) in there. Duration is not a basic datatype.

this is also working
"time_from_start": [1, 0]

Maybe that works, but I think a better way would be this:

    "time_from_start": {"sec": 1, "nanosec": 0}

[mintar]

I have just finished converting this repo to ROS2 and released it (as rclpy_message_converter) to ROS2 foxy, galactic, humble and rolling. It should be available as binary package after the next sync.

I used as much as I could from this PR (thanks a lot, @relffok!). I ended up re-doing a lot of it in order to keep the Git history and have nice commits. Also, I've ended up copying and modifying rosidl_runtime_py.set_message.set_message_fields() and rosidl_runtime_py.convert.message_to_orderreddict instead of adapting the old implementation.

The biggest thing that was missing from this PR (and from the rosidl_runtime_py implementations above) is the Base64 encoding of binary arrays (uint8[]). I haven't checked, but I'm pretty sure that the mir_robot driver transfers sensor_msgs/Image encoded this way. I've added back this functionality.

It now passes all the original tests, so I'm very confident that it works just as before.

[relffok]

Awesome, thank you. Glad I could contribute and looking forward to using it.

[mintar]

Thanks again. Without you taking the initiative I wouldn't have done it.