--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mod_muc_hide_media/mod_muc_hide_media.lua	Sun Sep 29 11:48:27 2019 +0100
@@ -0,0 +1,57 @@
+module:depends"muc";
+
+local hide_by_default = not module:get_option_boolean("muc_room_default_hide_media", false);
+
+local function should_hide_media(room)
+	local hide_media = room._data.hide_media;
+	if hide_media == nil then
+		hide_media = hide_by_default;
+	end
+	return hide_media;
+end
+
+module:hook("muc-config-form", function(event)
+	local room, form = event.room, event.form;
+	table.insert(form, {
+		name = "{xmpp:prosody.im}muc#roomconfig_display_media",
+		type = "boolean",
+		label = "Display inline media (images, etc.)",
+		value = not should_hide_media(room),
+	});
+end);
+
+module:hook("muc-config-submitted", function(event)
+	local room, fields, changed = event.room, event.fields, event.changed;
+	local new_hide_media = not fields["{xmpp:prosody.im}muc#roomconfig_display_media"];
+	if new_hide_media ~= should_hide_media(room) then
+		if new_hide_media == hide_by_default(room) then
+			room._data.hide_media = nil;
+		else
+			room._data.hide_media = new_hide_media;
+		end
+		if type(changed) == "table" then
+			changed["{xmpp:prosody.im}muc#roomconfig_display_media"] = true;
+		else
+			event.changed = true;
+		end
+	end
+end);
+
+module:hook("muc-disco#info", function (event)
+	local room, form, formdata = event.room, event.form, event.formdata;
+
+	local display_media = not should_hide_media(room);
+	table.insert(form, {
+		name = "{xmpp:prosody.im}muc#roomconfig_display_media",
+	});
+	formdata["{xmpp:prosody.im}muc#roomconfig_display_media"] = display_media;
+end);
+
+
+module:hook("muc-occupant-groupchat", function (event)
+	local stanza = event.stanza;
+	if stanza.attr.type ~= "groupchat" then return; end
+	if should_hide_media(event.room) then
+		stanza:remove_children("x", "jabber:x:oob");
+	end
+end, 20);