Google Calendar errors on importing .ics file

问题

I'm having a hard time getting my subscription calendar to work with Google Calendar. The following URL works correctly with Outlook and Apple Calendar (iCal), but I get an error from Google - "The address that you provided did not contain a calendar in a valid iCal or GData format."

My URL passes validation on the following validators (icalvalid.cloudapp.net/ and severinghaus.org/projects/icv/)

Can anyone provide any idea what is wrong? Here is the URL: https://beta.vcallboard.com/calls/exportcalendar.php?userID=Mg%3D%3D&token=MjB6N2E0OTk%3D

Theories I've already tried: - doesn't work over https - (I saved and uploaded the .ics file as a file in my server root and that URL worked - seems it has something to do with the auto-generation) - blank values for some fields aren't valid (it works if I upload it as a .ics file)

回答1:

You aren't defining the timezone that you are referencing in the ICS file. You have a number of lines as follows:

DTSTART;TZID=America/Chicago:20140121T010000

but to use these you need to define your timezone, for example:

BEGIN:VCALENDAR
PRODID:-//Google Inc//Google Calendar 70.9054//EN
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:PUBLISH
X-WR-CALNAME:Test calendar
X-WR-TIMEZONE:Indian/Reunion
BEGIN:VTIMEZONE
TZID:Indian/Reunion
TZURL:http://tzurl.org/zoneinfo/Indian/Reunion
X-LIC-LOCATION:Indian/Reunion
BEGIN:STANDARD
TZOFFSETFROM:+034152
TZOFFSETTO:+0400
TZNAME:RET
DTSTART:19110601T000000
RDATE:19110601T000000
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
...

A good place to obtain timezone definition files is tzurl.org

回答2:

I was baffled by my problem because I could manually import the .ics file that was output by my script and it was read by Google Calendar with no problem. So i figured I didn't have a problem with the actual format of the iCal file - I figured it had to be a problem with the headers or some server config. So I did a few experiments...

Long story short, I was able to get this to work on Google Calendar by doing the following:

1. Load up a variable with all the iCal data, pulling from the database, site constants etc. Make sure to use \r and \n for better validation in the validators.

   $iCal = "BEGIN:VCALENDAR\r
   VERSION:2.0\r
   PRODID:-//VirtualCallboard//".SITENAME."//EN\r
   CALSCALE:GREGORIAN\r
   METHOD:PUBLISH\r";
   while ($r=mysql_fetch_assoc($result))
   {
       // i do a bunch of stuff here to get variables ready for the output
       $iCal .= "BEGIN:VEVENT\r
   DTSTAMP:".gmdate("Ymd\THis\Z")."\r
   DTSTART:".date("Ymd\THis\Z", strtotime($r[tdstart]))."\r
   DTEND:'.date("Ymd\THis\Z",   strtotime($r[tdend]))."\r
   SUMMARY:$r[title]\r
   UID:$r[callid]@".$_SERVER['HTTP_HOST']."\r
   DESCRIPTION:$r[notes].\r
   LOCATION:$r[location_name].\r
   STATUS:CONFIRMED\r
   END:VEVENT\r\n";
   }
   $iCal .= "END:VCALENDAR";
   

2. Escape the special characters (all I know right now are commas). And then (here's the secret) - use file_put_contents to write the string in the iCal variable into a file with a .ics extension in a cache directory.

   //escape special characters.
   $iCal = str_replace(",","\,",$iCal);
   
   //output to a file
   $filename = 'site/cache/'.date("YmdHis").'.ics';
   file_put_contents($filename,$iCal);
   

3. Call the headers:

   //set correct content-type-header
   header("Content-Type:text/calendar");
   header("Content-Disposition:inline;filename=my_ical.ics");
   

4. Use file_get_contents to read the .ics data back out of the file and output it to the browser.

   print file_get_contents($filename);
   

5. cleanup the .ics file I created in my cache directory.

   unlink($filename);
   exit;
   

For some reason, which I can't explain, this made the exact same file work in Google Calendar. So this is compatible with Outlook, Google Calendar, and Apple Calendar.

来源：https://stackoverflow.com/questions/21275581/google-calendar-errors-on-importing-ics-file