I used the Oracle Calendar GUI client to create iCalendar and vCalendar exports for the same date range. The formats are obviously different, but the data extracted is similar. Exceptions: The vCalendar export includes “TODO” items from Oracle Calendar, which I’ve never used and don’t care about. And, the iCalendar export includes email addresses of attendees. I wonder if that’s what’s slowing it down. If the email lookup process is time consuming, it will REALLY drag things down, because our calendar server includes a LOT of entries with many attendees.
Also, earlier I tried importing one of these iCalendar files into Apple’s iCal app, and had problems. It would import one entry and then stop. Upon closer examination, I think I see why this is happening. The exported iCalendar file encloses every single event inside a separate BEGIN:VCALENDAR / END:VCALENDAR block, complete with all the vCalendar headers, etc.! In other words, it’s not a valid iCalendar-format file at all. iCal probably aborts when it sees the first END:VCALENDAR, thinking it’s done.
Anyhow, back to my earlier point, I decided to test my theory that the email lookups are dragging down the iCalendar export. The API allows me to explicitly specify which iCalendar properties I want included in the exported file. So, I told it to include just a small set of properties (start date, end date, summary), to see how it would do. Yep, the export was much faster. Now, I just need to build up the full set of properties I need, omit the attendee info, and see how it does then. Unfortunately, there’s no way to say “I want every property except attendee info.” I either have to request every property, or request a specific list. So, I’ll need to look at the iCalendar spec, get a full list of properties, and explicitly list out the ones I want. Kind of an annoying limitation if you ask me.
The other question is, is there a way to get the vCalendar format through the API? Or, assuming the email lookup is the culprit, can I pull attendee info without doing the email lookup? Dunno, but I’m getting a little ahead of myself here.