PHP generated calendar in Google Calendar - not valid URL - php

Question

I am a bit new to PHP.
I am trying to filter a ICS file for events containing a certain string. The following script seems to do that job just fine:
<?php
header('Content-type: text/calendar; charset=utf-8');
header('Content-Disposition: attachment; filename=fodda2009.ics');
header("Cache-Control: no-cache, must-revalidate");
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT");
function icsFilter($paramUrl,$filterstring) {
$icsFile = file_get_contents($paramUrl);
$icsData = explode("BEGIN:", $icsFile);
foreach($icsData as $value) {
if (strpos($value, "VEVENT") === FALSE) {
echo "BEGIN:";
echo $value;
}
else {
if (strpos($value, $filterstring) !== FALSE) {
echo "BEGIN:";
echo $value;
}
}
}
}
?>
<?php echo icsFilter('http://cal.laget.se/ALMTUNAISHOCKEYSKOLA.ics','dda 2009'); ?>
VEVENT
DESCRIPTION:Dummy info
DTEND;TZID=W. Europe Standard Time:20001010T121500
DTSTAMP:20001005T192952Z
DTSTART;TZID=W. Europe Standard Time:20001010T110000
SUMMARY:Dummy event
UID:200abc01010T110000-8918999#stackoverflow.com
END:VEVENT
END:VCALENDAR
I am hosting the script at http://mydomain.dyndns.com/mycalendar.php. When I enter that URL into Google Calendar (other calendars -> add by URL) I receive a message "[your URL] is not a valid URL".
Is this caused by the script ending in .php?
Do I need to convince my server (Apache) to call the php script at a http://mydomain.dyndns.com/mycalendar.ics URL? How? Is there something else I am doing wrong?

Answer 1

OK, this is a little embarrassing...
The code above works just fine, the source of my error was that I left out the "http://" from the URL. Thus Google Calendar complained that it wasn't a good URL. cough Adding "http://" to my URL worked wonders :)
I'll leave the script here, maybe someone else wants to have a simple PHP script to filter an existing iCal file and serve it to Google Calendar.