I noticed an issue with Office JS for Outlook. When I make an EWS call with 'makeEwsRequestAsync' to set a Extended Property of the current item, this value is overwritten when the meeting is send.
Looks like this only occurs in the Outlook client.
The exact scenario is:
1. Create new meeting;
2. Open the Add-In and save the meeting using 'saveAsync'; 3. Set the Extended Property using 'makeEwsRequestAsync';
4. Now I can read out the Extended Property. Also when I reopen the Add-In it's still available.
5. When I press 'Send' to send out the meeting, the Extended Property is not available anymore.
Looks like in step 1 a meeting is created locally in Outlook. And step 2,3,4 the meeting is stored on the server and I'm communicating with the server version. When the user presses 'Send' the local version, without the Extended Property, is send to the server and overwrites everything... There is no merge done.
Is this correct? Is there anyway to overcome this issue?