Support CalendarItem recurrences

[ecederstrand]

exchangelib doesn't yet support getting, setting or changing recurrence info on recurring calendar items.

Short introduction with examples: https://msdn.microsoft.com/en-us/library/office/dn727654(v=exchg.150).aspx
Reference: https://msdn.microsoft.com/en-us/library/office/aa580471(v=exchg.150).aspx

[jkottapa]

Hi Eric, I am interested in this enhancement. Is there anything that I can do to help, if you have already started on the implementation, are there any commits that I have a look at it to see if I can figure it out?

[ecederstrand]

Hi @Jayanth1991

I started but have just implemented parts of the necessary XML elements. What is needed is adding a recursion field to CalendarItem and lots of XML generation and parsing to read and produce the XML, and possibly a more user friendly API to create recurring items.

I'll commit my WIP in a branch tonight so you can have a look. Thanks!

[ecederstrand]

There's now a branch with the WIP: https://github.com/ecederstrand/exchangelib/tree/37_recurrence-support

Please post any progress here :-) Maybe it's easiest to start by just parsing recursion info on existing CalendarItems on the server.

[agentq15]

How is the work going with this? I can't get recurring items right now and almost all of my appointments are recurring.

[ecederstrand]

There's a branch with the current state, which is non-functional still. However, if you just need to view your appointments, there's the account.calendar.view(start, end) method which returns the recurring calendar items unfolded.

[agentq15]

Thank you, that method worked perfectly for my purpose :)

[sedemmler]

Am I just missing the function for accepting Calendar invitations or would that be on a separate branch? I love this repo, by the way. Thank you.

[ecederstrand]

Meeting invitations are only barely supported, meaning that exchangelib doesn't crash when encountering one in a folder. But there is no support yet for reading or answering meeting requests, cancellations or responses. Have a look at the Meeting* classes in exchangelib.folders if you want to give this a stab. It's a bit difficult for me to test ATM since my test server only has one account.

[sedemmler]

I'm happy to have a go at it.

[ecederstrand]

Cool. I opened #89 to track this, as it doesn't really have anything to do with calendar recurrences.

[ecederstrand]

There's now rudimentary support for reading recurring item info in the 37_recurrence-support branch

TODO: tests, write support, a simple API for creating recurrences, and docs

[ecederstrand]

We should now have full read-write recurrence support. There's support for creating daily, weekly, monthly and yearly recurrences (the latter two in relative and absolute versions). Everything is implemented in https://github.com/ecederstrand/exchangelib/blob/master/exchangelib/recurrence.py

Here's an example of creating 7 occurrences on Mondays and Wednesdays of every third week, starting September 1, 2017:

from exchangelib import CalendarItem, EWSDateTime, EWSTimeZone, EWSDate
from exchangelib.recurrence import Recurrence, WeeklyPattern, MONDAY, WEDNESDAY

item = CalendarItem(
    folder=a.calendar,
    start=tz.localize(EWSDateTime(2017, 9, 1, 11)),
    end=tz.localize(EWSDateTime(2017, 9, 1, 13)),
    subject='Hello Recurrence',
    recurrence=Recurrence(
        pattern=WeeklyPattern(interval=3, weekdays=[MONDAY, WEDNESDAY]), 
        start=EWSDate(2017, 9, 1), 
        number=7
    ),
)

# Occurrence data for the master item
for i in a.calendar.filter(start__lt=end, end__gt=start):
    print(i.subject, i.start, i.end)
    print(i.recurrence)
    print(i.first_occurrence)
    print(i.last_occurrence)
    for o in i.modified_occurrences:
        print(o)
    for o in i.deleted_occurrences:
        print(o)

# All occurrences expanded
for i in a.calendar.view(start=end, end=start):
    print(i.subject, i.start, i.end)

This is to be considered an experimental feature for now. Please play around with it and see if it does what you want. I'd like this to settle a bit before setting the API and functionality in stone in a release. Thanks.

[ecederstrand]

Tests added in 99b5770 I now consider this ready for general consumption.