CODEWITHSUNDEEP
c#exchangewebservices
YvesR
YvesR

Reputation: 6222

EWS SyncFolderItems - Delete appointments on client-database

I am working on a sync client that replicate appointment from and to EWS (Office 365).

In general I am following the documentation provided by MS: https://msdn.microsoft.com/en-us//library/office/dn440952(v=exchg.150).aspx

My problem: This article https://msdn.microsoft.com/en-us//library/office/dn605828(v=exchg.150).aspx#Arbeiten%20mit%20Bezeichnern shows that the ItemId of a appointment may change and is not unique.

So investigating I found out that people load cleanGlobalObjectId from appointment that is unique once and for all.

// unique id for sync that do not change like item id
var cleanGlobalObjectId = new ExtendedPropertyDefinition(DefaultExtendedPropertySet.Meeting, 0x23, MapiPropertyType.Binary);
var psPropSet = new PropertySet(BasePropertySet.FirstClassProperties) { cleanGlobalObjectId };

So I use

var appointment = Appointment.Bind(service, item, psPropSet);
object calIdVal;
appointment.TryGetProperty(cleanGlobalObjectId, out calIdVal);
var syncId = Convert.ToBase64String((byte[])calIdVal);

syncId is so far I tested unique and works for INSERT and UPDATE appointments into my database.

When I now use SyncFolderItems from EWS I get a collection of items for create,update,delete.

My problem:

I can not load appointments with Appointment.Bind() that are deleted. But I need to load the appointment to get my syncId.

The SyncFolderItems collection let me access ItemId.UniqueKey and ItemId.ChangeKey.

So if an appointment is moved or deleted in a users calendar I have no chance to identify the correct record in my client database where I save the replicated appointments.

So anyone have some advise or any other approaches? If I forgot to add some details please also provide some feedback so I can add this.

Upvotes: 1

Views: 541

Answers (1)

Henning Krause
Henning Krause

Reputation: 5422

You should save both, the cleanGlobalObjectId as well as the ItemId in your database. This way, you can tackle the removal of an item as well as the event that Exchange recreates your appointment (which doesn't happen all the time, just under certain circumstances).

Upvotes: 1

Related Questions