GetCalendarOptions Method

Retrieves options for the ResourceURI to determines whether it supports calendar access.

Syntax

[VB.NET]
Public Sub GetCalendarOptions(ByVal ResourceURI As String)

[C#]
public void GetCalendarOptions(string resourceURI);

Remarks

This method sends an OPTIONS HTTP request to the indicated ResourceURI. The server will respond with an 200 OK HTTP message, and the supported options will fire one-by-one in the Header event. If a server supports CalDAV calendar access, the "DAV" header will contain the string "calendar-access". The allowable CalDAV and WebDAV methods may also be returned in the "Allow" header.

For instance, the following headers may be returned from a call to the GetCalendarOptions method:

Field	Value
Allow	OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE
Allow	PROPFIND, PROPPATCH, LOCK, UNLOCK, REPORT, ACL
DAV	1, 2, access-control, calendar-access
Date	Sat, 11 Nov 2006 09:32:12 GMT
Content-Length	0

Since the "DAV" header contains "calendar-access", CalDAV is supported on this ResourceURI.

There is no standard format for resource URIs. Google for instance, uses "https://www.google.com/calendar/dav/" plus your email address to access the default calendar. So "https://www.google.com/calendar/dav/username@gmail.com/" is the base URI for the default calendar. If you have multiple calendars, replace the email address portion above with the Id of the calendar, plus "@group.calendar.google.com/". For instance: "https://www.google.com/calendar/dav/ev3nkr4ua83jej7q32oumn5eeo@group.calendar.google.com/". For Google, calendar events are stored in the "/events/" path. To retrieve a report on a calendar, you'd add "/events/" to one of the above paths. For example:

  CalDAV.GetCalendarReport("https://www.google.com/calendar/dav/username@gmail.com/events/");

Leaving the "/events/" out of the URI will result in an HTTP protocol error: 405 Method not allowed.

To add or retrieve an event, add the UID of the event you're creating or retrieving plus ".ics" to the path. Note that when putting an event with the PutCalendarEvent method, if the resourceURI and the UID do not match Google will create the event using the UID stored in the UID property. The actual location of will be newly added event will be returned in a "Location" header. This is the resource URI you must use to retrieve the event with GetCalendarEvent. For example:

  CalDAV.UID = "1234567890";
  CalDAV.PutCalendarEvent("https://www.google.com/calendar/dav/username@gmail.com/events/1234567890.ics");

Yahoo uses a different format for CalDAV access. Yahoo's ResourceURIs always start with "https://caldav.calendar.yahoo.com/dav/" plus your user name, plus "/Calendar/" plus the name of your calendar. For instance: "https://caldav.calendar.yahoo.com/dav/username/Calendar/Your_Name" for the default calendar. (Yahoo uses your name to create the default calendar). When using the CreateCalendar event to create a new calendar, replace "Your_Name" in the URI with the desired name of your new calendar. Event resources are located directly under the "/Calendar/Calendar_Name/" path. Like Google, the UID and filename portion of the resource URI must match, but Yahoo will actually return an HTTP protocol error if they differ. The examples below show a few possible transactions:

  CalDAVS1.User = "username";
  CalDAVS1.Password = "password";
  
  CalDAV.DisplayName = "My Hockey Calendar";
  CalDAV.CreateCalendar("https://caldav.calendar.yahoo.com/dav/username/Calendar/Hockey_Calendar/");
  
  CalDAV.StartDate = "20100401T040000";
  CalDAV.EndDate = "20100401T060000";
  CalDAV.UID = "qwerty1234567";
  CalDAV.Summary = "First Practice";
  CalDAV.Location = "Rink on 1st and main";
  CalDAV.EventType = vEvent;
  CalDAV.PutCalendarEvent("https://caldav.calendar.yahoo.com/dav/username/Calendar/Hockey_Calendar/qwerty1234567.ics");
  
  CalDAV.GetCalendarReport("https://caldav.calendar.yahoo.com/dav/username/Calendar/Hockey_Calendar/");