Feature Request: Allow publish pane to publish std_msgs::Empty

[marcelino-pensa]

I feel like one of the most useful features of buttons in GUIs is to just send a trigger request. This can be easily made through a std_msgs::Empty publish in a given topic, but this isn't available in webviz. It isn't a big deal not to be able to publish std_msgs::Empty because we can publish std_msgs::Bool instead. However, I'll leave this issue here in case y'all want to tackle it sometime in the future

Currently allowed msgs from std_msgs:

[jhurliman]

@marcelino-pensa the only natively supported datatypes in webviz are 3D markers and 3D marker arrays, I believe. You are likely seeing some of the datatypes in that list because other running nodes are publishing topic using those types. I just merged a change into Foxglove Studio to support the majority of ros/common_msgs datatypes out of the box.

[marcelino-pensa]

Thanks, @jhurliman! I just ran a dummy node that had one publisher and one subscriber to std_msgs/Empty, but webviz did not list it as an option for a data type... it might be that some part of webviz's pipeline does not like an empty message definition, and it might be a bit confused with that... But you are right, I have made some custom msg definitions (non-standard ros messages), and webviz shows them with no problem, the issue just seems to be with Empty itself As for your merge, when should we expect it to get into https://webviz.io/app/? Or is it supposed to show already?

[marcelino-pensa]

Ooh, I have just realized that Foxglove is a fork of webviz! I'll take a look at it (and perhaps move our applications to Foxglove) when I get some time Thanks for the feedback, though!