Also dynamically create a tag for Firefox

awesome/.config/awesome/rc.lua

@@ -511,11 +511,14 @@ client.connect_signal("manage", function (c, startup)
           awful.client.setslave(c)
        end
 
-       if awful.rules.match(c, { class = "Dia" }) then
+       if awful.rules.match_any(c, { class = { "Dia", "Firefox" } }) then
-          tags["Dia"] = tags["Dia"] or awful.tag.add("Dia", {layout = awful.layout.suit.tile})
+          tags[c.class] = tags[c.class] or
+             awful.tag.add(c.class, {layout = awful.layout.suit.tile})
+          awful.tag.viewonly(tags[c.class])
+          awful.client.movetotag(tags[c.class], c)
+       end
 
-          awful.tag.viewonly(tags["Dia"])
+       if awful.rules.match(c, { class = "Dia" }) then
-          awful.client.movetotag(tags["Dia"], c)
           awful.tag.setmwfact(0.90, tags["Dia"])
        end
 
@@ -528,10 +531,10 @@ client.connect_signal("manage", function (c, startup)
 end)
 
 client.connect_signal("unmanage", function(c)
-    if awful.rules.match(c, { class = "Dia" }) then
+    if awful.rules.match_any(c, { class = { "Dia", "Firefox" } }) then
-       if #tags["Dia"]:clients() == 0 then
+       if tags[c.class] and #tags[c.class]:clients() == 0 then
-          awful.tag.delete(tags["Dia"])
+          awful.tag.delete(tags[c.class])
-          tags["Dia"] = nil
+          tags[c.class] = nil
        end
     end
 end)