Forbidden error : While fetching events from iCloud using caldav extension - icloud

Question

URL -: https://pxx-caldav.icloud.com/token/calendars/calendarId
#"<C:calendar-query xmlns:D='DAV:'
xmlns:C='urn:ietf:params:xml:ns:caldav'>
<D:prop>
<D:getetag/>
<C:calendar-timezone xmlns:D='DAV:' xmlns:C='urn:ietf:params:xml:ns:caldav'></C:calendar-timezone>
<C:calendar-data>
<C:expand start='{0}'
end='{1}'/>
<C:comp name='VCALENDAR'>
<C:prop name='VERSION'/>
<C:comp name='VEVENT'>
<C:prop name='SUMMARY'/>
<C:prop name='DESCRIPTION'/>
<C:prop name='STATUS'/>
<C:prop name='TRANSP'/>
<C:prop name='ATTENDEE'/>
<C:prop name='UID'/>
<C:prop name='DTSTART'/>
<C:prop name='DTEND'/>
<C:prop name='DURATION'/>
<C:prop name='RRULE'/>
<C:prop name='RDATE'/>
<C:prop name='EXRULE'/>
<C:prop name='EXDATE'/>
<C:prop name='RECURRENCE-ID'/>
</C:comp>
</C:comp>
</C:calendar-data>
</D:prop>
<C:filter>
<C:comp-filter name='VCALENDAR'>
<C:comp-filter name='VEVENT'>
<C:time-range start='{0}'
end='{1}'/>
</C:comp-filter>
</C:comp-filter>
</C:filter>
</C:calendar-query>"
while retrieving events it gives forbidden error on some particular calendars of some accounts. While retrieving calendars it shows read/write access but while fetching events it gives error. It gives error on few calendars but error is continuous on them.
I am getting following error -:
<error> <supported-report /> </error>

Answer 1

Calendars are WebDAV collections with a DAV:resourcetype of C:calendar (see https://www.rfc-editor.org/rfc/rfc4791#section-4.2 ) but there are other types of collections (calendar home, scheduling inbox, dropbox, etc...).
What is most likely happening is that you are issuing a calendar query against a collection which is not a calendar collection, hence the supported-report error.
You need to retrieve the DAV:resourcetype property of each collection and, only if it is a calendar, issue the above report.