If you access a CalDav calendar on machine A and machine B, then the UID for this calendar will be different as the UID is unique to the machine (regardless of where the actual calendar resides). Because of this limitation, syncing in a multi-user environment requires a bit more work.
You can store the UIDs for each user in FileMaker for future reference (option 1) or you could also use one computer to “sync” with iCal using iCal Server (option 2).
Please note that “sync” methods are more complex in a multi-user environment if FileMaker is not designated as the “master”. Therefore, we typically recommend having FileMaker as your master and pushing to iCal.
We recommend designating a data exchange between only one user’s iCal and FileMaker. All of you users can still keep their new and/or altered events in iCal, but you will simply be using iCal Server to do the syncing and then you can go direct to FileMaker from ONE machine allowing you to use the UID as the unique identifier and this will be much simpler.
For example: Designating one machine in your business as the “Master iCal Client”. We will call this “Mac 1”. Mac 1 would be the only Mac using the iCal Manipulator and “syncing” with FM. Then you could use iCal Server to communicate and update all your other Macs allowing you to individually sync with each users iCal right from iCal Server. Using this method, you also only need one license of the iCal Manipulator.
Syncing in a multi user environment is never an easy task. We have not personally used the iCal Server in our environment but have heard great reviews of the functionality.
It may also be more beneficial to have a remote session under our paid support services with a developer so we can better assist you and answer all your design, script and development questions. Please contact us Our developers typically are available Monday - Friday 8:00am - 5:00pm PST.