support ros2 topic pub yaml file input

[fujitatomoya]

closes #919

[fujitatomoya]

This enables the following command line option with ros2 topic pub.

Note that yaml files are saved with ros2 topic echo > xxx.yaml.

root@tomoyafujita:~/ros2_ws/colcon_ws# cat chatter.yaml
---
data: 'Hello ROS Users'
---
---
data: Hello ROS Developers
---
data: Hello ROS Developers
---
---
data: 'Hello ROS Users'

root@tomoyafujita:~/ros2_ws/colcon_ws# ros2 topic pub /chatter std_msgs/msg/String --yaml-file chatter.yaml
publisher: beginning loop
publishing #1: std_msgs.msg.String(data='Hello ROS Users')

publishing #2: std_msgs.msg.String(data='Hello ROS Developers')

publishing #3: std_msgs.msg.String(data='Hello ROS Developers')

publishing #4: std_msgs.msg.String(data='Hello ROS Users')

root@tomoyafujita:~/ros2_ws/colcon_ws# cat tf2.yaml
transforms:
- header:
    stamp:
      sec: 1721935886
      nanosec: 528868866
    frame_id: foo
  child_frame_id: bar
  transform:
    translation:
      x: 1.0
      y: 2.0
      z: 3.0
    rotation:
      x: -0.4747921762038255
      y: -0.07596622270177095
      z: 0.24006245183344296
      w: 0.8433098728485138
---
transforms:
- header:
    stamp:
      sec: 1721935886
      nanosec: 528868866
    frame_id: foo
  child_frame_id: bar
  transform:
    translation:
      x: 1.0
      y: 2.0
      z: 3.0
    rotation:
      x: -0.4747921762038255
      y: -0.07596622270177095
      z: 0.24006245183344296
      w: 0.8433098728485138

root@tomoyafujita:~/ros2_ws/colcon_ws# ros2 topic pub /tf_static tf2_msgs/msg/TFMessage --yaml-file tf2.yaml
publisher: beginning loop
publishing #1: tf2_msgs.msg.TFMessage(transforms=[geometry_msgs.msg.TransformStamped(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=1721935886, nanosec=528868866), frame_id='foo'), child_frame_id='bar', transform=geometry_msgs.msg.Transform(translation=geometry_msgs.msg.Vector3(x=1.0, y=2.0, z=3.0), rotation=geometry_msgs.msg.Quaternion(x=-0.4747921762038255, y=-0.07596622270177095, z=0.24006245183344296, w=0.8433098728485138)))])

publishing #2: tf2_msgs.msg.TFMessage(transforms=[geometry_msgs.msg.TransformStamped(header=std_msgs.msg.Header(stamp=builtin_interfaces.msg.Time(sec=1721935886, nanosec=528868866), frame_id='foo'), child_frame_id='bar', transform=geometry_msgs.msg.Transform(translation=geometry_msgs.msg.Vector3(x=1.0, y=2.0, z=3.0), rotation=geometry_msgs.msg.Quaternion(x=-0.4747921762038255, y=-0.07596622270177095, z=0.24006245183344296, w=0.8433098728485138)))])

[fujitatomoya]

@mjcarroll @clalancette @sloretz what do you think? this can be useful for test and development.

[fujitatomoya]

CC: @ahcorde if you have time, can you take a look?

[ahcorde]

This is a simplification of a rosbag, not sure about this feature, let's see what other people thing about it

[fujitatomoya]

This is a simplification of a rosbag, not sure about this feature, let's see what other people thing about it

yeah that is true.

the difference what i think of is, probably much easier to use and modify the data contents that are saved as yaml via ros2 topic echo. we have a chat about this in triage meeting, #919 (comment) but yes lets get more feedback for this feature. see usage for #925 (review)

CC: @Ryanf55 @mjcarroll @clalancette

[fujitatomoya]

@clalancette @sloretz what do you think about this option? it would be really easier for user to update the data contents and publish it compared to rosbag2.

[Ryanf55]

Sorry, I realized I never submitted my review. This functions exactly as I requested. I'm a big fan of this feature and would love to see it merged.

I think it's a much more usable way to publish messages and be able to edit the contents in a human readable way.

Currently, I would write a shell script with `ros2 topic pub /my_topic my_pkg/mytype
"{
and: [manually_formatted_yaml, in_a_shell_script]
}"

Where it's easy to mess up the syntax in a shell script without yaml syntax in my editor. This PR represents a significant improvement in readability and helps me document in README's example messages to publish to affect the state of my robotic system.