Add Read event support. Update description of Delivered events (#7)

* Added Read message support
Delivered message suppport already existed but was commented as
indicating that a message was read by a user. As of the 1 July
2016 API release this isn't true, there is another event. This
commit adds read event support and corrects the description of
delivered events. Also added to the example bot.

* go fmt

* Added new profile fields from July 1st API update

* gofmt

actions.go

@@ -8,9 +8,12 @@ const (
 	UnknownAction Action = iota - 1
 	// TextAction means that the event was a text message (May contain attachments).
 	TextAction
-	// DeliveryAction means that the event was a previous recipient reading their respective
-	// messages.
+	// DeliveryAction means that the event was advising of a successful delivery to a
+	// previous recipient.
 	DeliveryAction
+	// ReadAction means that the event was a previous recipient reading their respective
+	// messages.
+	ReadAction
 	// PostBackAction represents post call back
 	PostBackAction
 )

cmd/bot/main.go

@@ -42,9 +42,14 @@ func main() {
 		r.Text(fmt.Sprintf("Hello, %v!", p.FirstName))
 	})
 
-	// Setup a handler to be triggered when a message is read
+	// Setup a handler to be triggered when a message is delivered
 	client.HandleDelivery(func(d messenger.Delivery, r *messenger.Response) {
-		fmt.Println(d.Watermark().Format(time.UnixDate))
+		fmt.Println("Delivered at:", d.Watermark().Format(time.UnixDate))
+	})
+
+	// Setup a handler to be triggered when a message is read
+	client.HandleDelivery(func(m messenger.Read, r *messenger.Response) {
+		fmt.Println("Read at:", m.Watermark().Format(time.UnixDate))
 	})
 
 	fmt.Println("Serving messenger bot on localhost:8080")

message.go

@@ -21,12 +21,22 @@ type Message struct {
 	Attachments []Attachment `json:"attachments"`
 }
 
-// Delivery represents a the event fired when a recipient reads one of Messengers sent
-// messages.
+// Delivery represents a the event fired when Facebook delivers a message to the
+// recipient.
 type Delivery struct {
 	// Mids are the IDs of the messages which were read.
 	Mids []string `json:"mids"`
-	// RawWatermark is the timestamp contained in the message of when the read was.
+	// RawWatermark is the timestamp of when the delivery was.
+	RawWatermark int64 `json:"watermark"`
+	// Seq is the sequence the message was sent in.
+	Seq int `json:"seq"`
+}
+
+// Delivery represents a the event fired when a message is read by the
+// recipient.
+type Read struct {
+	// RawWatermark is the timestamp before which all messages have been read
+	// by the user
 	RawWatermark int64 `json:"watermark"`
 	// Seq is the sequence the message was sent in.
 	Seq int `json:"seq"`
@@ -48,3 +58,8 @@ type PostBack struct {
 func (d Delivery) Watermark() time.Time {
 	return time.Unix(d.RawWatermark, 0)
 }
+
+// Watermark is the RawWatermark timestamp rendered as a time.Time.
+func (r Read) Watermark() time.Time {
+	return time.Unix(r.RawWatermark, 0)
+}

messenger.go

@@ -30,9 +30,12 @@ type Options struct {
 // MessageHandler is a handler used for responding to a message containing text.
 type MessageHandler func(Message, *Response)
 
-// DeliveryHandler is a handler used for responding to a read receipt.
+// DeliveryHandler is a handler used for responding to a delivery receipt.
 type DeliveryHandler func(Delivery, *Response)
 
+// ReadHandler is a handler used for responding to a read receipt.
+type ReadHandler func(Read, *Response)
+
 // PostBackHandler is a handler used postback callbacks.
 type PostBackHandler func(PostBack, *Response)
 
@@ -41,6 +44,7 @@ type Messenger struct {
 	mux              *http.ServeMux
 	messageHandlers  []MessageHandler
 	deliveryHandlers []DeliveryHandler
+	readHandlers     []ReadHandler
 	postBackHandlers []PostBackHandler
 	token            string
 	verifyHandler    func(http.ResponseWriter, *http.Request)
@@ -70,11 +74,17 @@ func (m *Messenger) HandleMessage(f MessageHandler) {
 }
 
 // HandleDelivery adds a new DeliveryHandler to the Messenger which will be triggered
-// when a previously sent message is read by the recipient.
+// when a previously sent message is delivered to the recipient.
 func (m *Messenger) HandleDelivery(f DeliveryHandler) {
 	m.deliveryHandlers = append(m.deliveryHandlers, f)
 }
 
+// HandleRead adds a new DeliveryHandler to the Messenger which will be triggered
+// when a previously sent message is read by the recipient.
+func (m *Messenger) HandleRead(f ReadHandler) {
+	m.readHandlers = append(m.readHandlers, f)
+}
+
 // HandlePostBack adds a new PostBackHandler to the Messenger
 func (m *Messenger) HandlePostBack(f PostBackHandler) {
 	m.postBackHandlers = append(m.postBackHandlers, f)
@@ -159,6 +169,10 @@ func (m *Messenger) dispatch(r Receive) {
 				for _, f := range m.deliveryHandlers {
 					f(*info.Delivery, resp)
 				}
+			case ReadAction:
+				for _, f := range m.readHandlers {
+					f(*info.Read, resp)
+				}
 			case PostBackAction:
 				for _, f := range m.postBackHandlers {
 					message := *info.PostBack
@@ -178,6 +192,8 @@ func (m *Messenger) classify(info MessageInfo, e Entry) Action {
 		return TextAction
 	} else if info.Delivery != nil {
 		return DeliveryAction
+	} else if info.Read != nil {
+		return ReadAction
 	} else if info.PostBack != nil {
 		return PostBackAction
 	}

profile.go

@@ -5,4 +5,7 @@ type Profile struct {
 	FirstName     string `json:"first_name"`
 	LastName      string `json:"last_name"`
 	ProfilePicURL string `json:"profile_pic"`
+	Locale        string `json:"locale"`
+	Timezone      int    `json:"timezone"`
+	Gender        string `json:"gender"`
 }

receiving.go

@@ -35,6 +35,8 @@ type MessageInfo struct {
 	Delivery *Delivery `json:"delivery"`
 
 	PostBack *PostBack `json:"postback"`
+
+	Read *Read `json:"read"`
 }
 
 // Sender is who the message was sent from.