Adds Key()

channel.go

@@ -28,3 +28,12 @@ type Channel struct {
 	Author   Author
 	SubTitle SubTitle
 }
+
+func (c *Channel) Key() string {
+	switch {
+	case len(c.Id) != 0:
+		return c.Id
+	default:
+		return c.Title
+	}
+}

feed.go

@@ -171,13 +171,13 @@ func (this *Feed) makeFeed(doc *xmlx.Document) (err error) {
 func (this *Feed) notifyListeners() {
 	var newchannels []*Channel
 	for _, channel := range this.Channels {
-		if this.database.request <- channel.Title; <-this.database.response {
+		if this.database.request <- channel.Key(); !<-this.database.response {
 			newchannels = append(newchannels, channel)
 		}
 
 		var newitems []*Item
 		for _, item := range channel.Items {
-			if this.database.request <- item.Title; <-this.database.response {
+			if this.database.request <- item.Key(); !<-this.database.response {
 				newitems = append(newitems, item)
 			}
 		}

item.go

@@ -19,3 +19,14 @@ type Item struct {
 	Contributors []string
 	Content      *Content
 }
+
+func (i *Item) Key() string {
+	switch {
+	case i.Guid != nil && len(*i.Guid) != 0:
+		return *i.Guid
+	case len(i.Id) != 0:
+		return i.Id
+	default:
+		return i.Title + i.PubDate
+	}
+}