Diff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/plugins/muc/hats.lib.lua	Thu Nov 05 22:31:25 2020 +0100
@@ -0,0 +1,24 @@
+local st = require "util.stanza";
+local muc_util = module:require "muc/util";
+
+local xmlns_hats = "xmpp:prosody.im/protocol/hats:1";
+
+-- Strip any hats claimed by the client (to prevent spoofing)
+muc_util.add_filtered_namespace(xmlns_hats);
+
+module:hook("muc-build-occupant-presence", function (event)
+	local aff_data = event.room:get_affiliation_data(event.occupant.bare_jid);
+	local hats = aff_data and aff_data.hats;
+	if not hats then return; end
+	local hats_el;
+	for hat_id, hat_data in pairs(hats) do
+		if hat_data.active then
+			if not hats_el then
+				hats_el = st.stanza("hats", { xmlns = xmlns_hats });
+			end
+			hats_el:tag("hat", { uri = hat_id, title = hat_data.title }):up();
+		end
+	end
+	if not hats_el then return; end
+	event.stanza:add_direct_child(hats_el);
+end);