Only alert on change of state.

storage.go

@@ -6,7 +6,7 @@ import (
 	"os"
 )
 
-type Listener func(status SpaceStatus)
+type Listener func(old, new SpaceStatus)
 
 type Storage struct {
 	filePath  string
@@ -31,19 +31,20 @@ func (s *Storage) Status() SpaceStatus {
 }
 
 func (s *Storage) Modify(modifiers ...func(*SpaceStatus)) {
+	old := s.status
 	for _, m := range modifiers {
 		m(&s.status)
 	}
-	s.notify()
+	s.notify(old, s.status)
 }
 
 func (s *Storage) AddListener(l Listener) {
 	s.listeners = append(s.listeners, l)
 }
 
-func (s *Storage) notify() {
+func (s *Storage) notify(old, new SpaceStatus) {
 	for _, l := range s.listeners {
-		l(s.status)
+		l(old, new)
 	}
 }
 

xmpp/xmpp.go

@@ -70,13 +70,17 @@ func AddXMPPListener(storage *spaceapi.Storage, jid, password, target, handle st
 		}
 	}()
 
-	storage.AddListener(func(status spaceapi.SpaceStatus) {
-		if status.State.Open == nil {
+	storage.AddListener(func(old, new spaceapi.SpaceStatus) {
+		if new.State.Open == nil {
+			return
+		}
+
+		if old.State.Open == new.State.Open {
 			return
 		}
 
 		msg := "Space is now OPEN!"
-		if !*status.State.Open {
+		if !*new.State.Open {
 			msg = "Space is now CLOSED!"
 		}