Can you help me with this? Write an example client using your ideal way of doing this. Put that in a Gist and link it here. Then we can work out the details.

This is how I'd like to see this feature.

http://gist.github.com/116882

I hope comments are not too confusing ;)

I'm liking this. Here's what I'm thinking about the DSL side. Though I'm still hesitant about stripping the html to create the plaintext. I'm going do a little more research to see how other client handle this.

http://gist.github.com/117620

WRT your last handler:

message :chat?, :body => /trim_html_down_to_plain_text/ do |m|

body is a node in the message stanza that contains the plaintext body, while html contains the html message. I think it'd be misleading to automatically fill the body with stripped html. This handler could be re-written with using a block guard that strips the html on a case-by-case basis.

It looks like leaving out the plaintext body is not standard–compliant.
http://xmpp.org/extensions/xep-0071.html

The only solution comes to mind is to convert html to textile. This will keep message readable and preserve most of the markup (lists, text styles, etc).

hm.. that's a good idea. We can default to textile, but build it to be plug-able so it could use any markup syntax.

I would love to see formatting support too.
Right now I am using XMPP4R and I do use stripped html for the plain text body. It really doesn't bother me at all. It actually bothers me I can't do this in Blather currently :-)
Textile will be fine too off course.

Maybe say should accept xhtml bodies and just convert it to textile when there isn't a seperate xhtml version given? When :text and :xhtml are given it should handle both in a different way.