Contents of action goal not exposed? about rosnodejs HOT 4 CLOSED

Hi Justin! Nice to "meet" you this way.

I'm not up to speed on the new ActionServer, I think it's still somewhat early in the development of it. But you can always fall back to just subscribing (goal and cancel) and publishing (result, feedback, and status) messages on the five action topics, because that's all action servers really do.

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Actually, looking at the code, can't you just listen for 'goal' events on the ActionServerInterface?

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Thanks Christian, it's nice to meet you, too.

My understanding is that action servers provide added value on top of publishing to the 5 topics, mostly bookkeeping in terms of the goal IDs and timestamps. I could subscribe to the goal and cancel topics, but without doing the bookkeeping myself, my action server probably won't conform to other action client implementations.

Handling ActionServerInterface's goal event gives me the contents of the goal message, but it doesn't create a GoalHandle.

I'm personally content to work around this issue by just creating a fork and making a small change. However, I'm curious what the long-term plan is for action servers. Does someone already plan on more fully implementing action servers? Or is it something that's awaiting outside contributions?

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All very true. The ActionServerInterface makes minimal action servers possible, but misses a lot of the details.

Giving access to the actual goal also seems to be something I missed in trying to parse the guts of actionlib's source code... feel free to make a pull request if you have the opportunity. I haven't had time to come back to it since the initial work.

It's probably also worth mentioning that we recently (yesterday, actually) pulled the actions in rosnodejs into a new repo at actionlib_nodejs. The main reason for doing so is to allow different JS client libraries (rclnodejs, for example) to share a common actionlib backend rather than having to reimplement it on their own. There hasn't been any work there beyond pulling the ActionServer and GoalHandle classes into the repo. At some point active development on actions will hopefully move there, and how exactly client libraries and the separate actionlib repo interact is still up in the air. So, yes, we are planning to finish implementing actions, though outside contributions would be very welcome.

While I'm on the subject of "other" repos, we also created a tf2_nodejs repo a little while ago. Also still a work-in-progress. And would also benefit from outside help if anybody has time.

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