Gstreamer tag usage

I’m working on a Ruby application which uses the GStreamer bindings, and
I’ve got playback working quite well, but I am very confused about the
Gst::Tag (and Gst::TagSetter) usage.

I am inexperienced with GStreamer, but I believe that in order to read
metadata from my stream, I need to create some sort of listener on the
pipeline and grab the data as it goes past. Does anyone know if that is
possible with the bindings as they currently are, or point me to some
documentation or examples by which I could learn?

The examples provided with the ruby-gst bindings that manipulate tags
are not too useful, since (it appears) they don’t work.

-Payton