From 6b6086e389ec379b665d08263c84b16a2bdfbb44 Mon Sep 17 00:00:00 2001
From: Harm Aarts <harmaarts@gmail.com>
Date: Thu, 5 Dec 2013 16:04:00 +0100
Subject: [PATCH] Adds Key()

---
 channel.go |  9 +++++++++
 feed.go    |  4 ++--
 item.go    | 11 +++++++++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/channel.go b/channel.go
index f602675..fe3318b 100644
--- a/channel.go
+++ b/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
+	}
+}
diff --git a/feed.go b/feed.go
index 05c6e52..c0db240 100644
--- a/feed.go
+++ b/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)
 			}
 		}
diff --git a/item.go b/item.go
index c5e65fb..86b1cad 100644
--- a/item.go
+++ b/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
+	}
+}