Fixed the way cancellation is determined (fixes #3)

src/calanonsync/calanonsync.go

@@ -25,7 +25,7 @@ func main() {
 
 	for _, item := range items {
 		// Ignore private items.
-		if item.Sensitivity != "Private" && !item.IsCancelled {
+		if item.Sensitivity != "Private" && !item.IsCancelled() {
 			// None-private items though ... remember them by hash.
 			// The hash will equal the CalDAV UID (and its filename).
 			relevantEWSItems[item.Hash()] = item

src/calanonsync/ews.go

@@ -29,10 +29,18 @@ type CalendarItem struct {
 	RecurrenceId     string
 	Sensitivity      string
 	CalendarItemType string
-	IsCancelled      bool
+	AppointmentState AppointmentState
 	IsAllDayEvent    bool
 }
 
+type AppointmentState int
+
+const (
+	AppointmentStateMeeting   AppointmentState = 1 << iota // This appointment is a meeting.
+	AppointmentStateReceived                               // This appointment has been received.
+	AppointmentStateCancelled                              // This appointment has been canceled.
+)
+
 // Build a hash for the given calendar item by combining the UID and
 // the recurrenceId therefore guaranteeing a unique identifier for the
 // event, even if it has been a calculated recurrence (which would
@@ -44,6 +52,10 @@ func (ci CalendarItem) Hash() string {
 	return strings.ToUpper(hex.EncodeToString(h.Sum(nil)))
 }
 
+func (ci CalendarItem) IsCancelled() bool {
+	return ci.AppointmentState&AppointmentStateCancelled != 0
+}
+
 type EWSCalendar struct {
 	httpClient *http.Client
 	url        string
@@ -262,7 +274,7 @@ var calendarQuery = template.Must(template.New("calendarQuery").Parse(`<?xml ver
           <t:FieldURI FieldURI="calendar:End" />
           <t:FieldURI FieldURI="calendar:UID" />
           <t:FieldURI FieldURI="calendar:RecurrenceId" />
-          <t:FieldURI FieldURI="calendar:IsCancelled" />
+          <t:FieldURI FieldURI="calendar:AppointmentState" />
           <t:FieldURI FieldURI="calendar:CalendarItemType" />
           <t:FieldURI FieldURI="calendar:IsAllDayEvent" />
         </t:AdditionalProperties>