Calendar:Device Sync

Device Sync

We are working on the ability to synchronize calendar with handhelds (pda's). This should with a wide range of devices, and on the main platforms (windows, linux, mac). It should work with all types of calendars that we offer (ics, caldav, sqlite)

• On linux, communicating with the handheld can either be done directly (libvisor) or by third party software, such as multisync/opensync
• On windows, there is activesync and hotsync (iirc). But I don't know enough of them to decide what to use. What are its capabilities? Does it have sync logic build in?
• AIUI, HotSync is a Palm-specific (closed) sync client, while ActiveSync is (closed) WinCE-specific. You can write conduits for HotSync; I think there are dev kits available for this. I don't know about ActiveSync. Syncing to mobile devices also includes mobiles IMHO, which will probably use a mix of sync clients (e.g. Siemens S55 uses XTNDConnectPC, Motorola use StarFish's TrueSync) which could all probably have "conduit" equivalents written for them. I don't know if this is the approach you want - it's potentially a lot of different interfaces. -- BenS
• An addition to BenS comment above: Late-model Sony Ericsson phones also use XTNDConnectPC to sync with Windows and also directly with Microsoft Outlook.
• On mac, i don't know the situation at all.
• There's something called ".Mac" sync on OS X. To integrate with this, you can use the DotMac SDK [[1]] -- BenS
• A clarification to BenS comment about syncing on OS X: Apple's OS X operating system ships with an application called iSync. This is a SyncML application that supports syncing contacts and calendars with Bluetooth-enabled devices, PalmOS devices, iPod devices, other Macs, as well as Apple's .Mac service.
• The iPod supports iCal files for it's calander. Files only need to be copied to this folder, and no special sync protocol is needed. (AFAIK). As of yet nothing supports calander syncing with iPod on windows out of the box, "iPod Agent" (http://www.ipodsoft.com/softwaredetail.aspx?sid=1) adds this ability but not into Outlook itself. -- Kroc Camen.

Calendar already needs to have support for syncing two calICalendars (see Calendar:Networking Sharing Syncing). The logic to sync two calendars could be reused, either by implementing a calICalendar for the handheld, or by making the logic a little bit more general.

Another approach is to make the third party app export the handheld data into a file calendar can read. This calendar can then be synced, and after that the third party app can send the data back to the handheld.

The third way is to create some ipc between calendar and the thirdparty app, and let that app do the logic. multisync has the logic build in, but what about windows and mac? And do we want to depend on multisync?

The downside with those approaches is that calendar needs to run while syncing. This is mainly because we also want syncing to work with non-ics calendars, like caldav.

SyncML

SyncML is a standard, but can we use it safely without any worries?

• AIUI (from reading other projects' mailing lists and web pages), it is implemented slightly differently across different clients, but I would have thought you could get logic from multisync, likely not as a library, as they depend on GNOME libs and the like, but certainly by reading their code. There is certification for interoperability of SyncML products; the list is long and at [[2]]. NB it can use HTTP as a transport, and a fair few of the clients on that list seem to support HTTP rather than OBEX; this should be relatively easy to integrate into Mozilla :-) - BenS
• All of the IPR patents for SyncML are presently only at application stage according to the Open Mobile Alliance's IPR Declaration page [[3]]. If they make it through, I'm guessing either the Moz Foundation or users would have to pay licensing on it. What's the policy on this kind of thing? - BenS

• Most Symbian OS Series 60 and above, late-model Sony Ericsson, and (AFIACT) all >=2004 Motorola phones have SyncML support in one form or another. Some only via OTA (Over The Air, ie: HTTP), and some like the new Motorola Linux-based phones (a768i, a780) support it via OTA, USB and infrared. One benefit of SyncML support, as BenS noted, would be a large base of device support.

• Apple's OS X operating system ships with iSync, a SyncML application that supports syncing contacts and calendars with Bluetooth-enabled devices, PalmOS devices, iPod devices, other Macs, as well as Apple's .Mac service.

Help Wanted

To make a plan that will work, we need to know what the situation is on Windows and on MacOSX. What apis are available to talk to handhelds? What logic is available?

If you know more about those platforms from a developers perspective, please note it.