I'm looking for an easy way to parse VCALENDAR data with objective-c. Specifically all I am concerned with is the FREEBUSY data (See below):
BEGIN:VCALENDAR
VERSION:2.0
METHOD:REPLY
PRODID:-//CALENDARSERVER.ORG//NONSGML Version 1//EN
BEGIN:VFREEBUSY
UID:XYZ-DONT-CARE
DTSTART:20090605T070000Z
DTEND:20090606T070000Z
ATTENDEE:/principals/__uids__/ABC1234-53D8-4079-8392-01274F97F5E1/
DTSTAMP:20090605T075430Z
FREEBUSY;FBTYPE=BUSY:20090605T170000Z/20090605T200000Z,20090605T223000Z/20
090606T003000Z
FREEBUSY;FBTYPE=BUSY-UNAVAILABLE:20090605T070000Z/20090605T150000Z,2009060
6T010000Z/20090606T070000Z
ORGANIZER:/principals/__uids__/ABC1234-53D8-4079-8392-01274F97F5E1/
END:VFREEBUSY
END:VCALENDAR
I've tried parsing it by using componentsSeparatedByString:@"\n", but there is a \n in part of the FREEBUSY data, causing it to not parse correctly.
Is there something easy that I'm missing?
The \n
in the middle of FREEBUSY data is a part of the iCalendar spec; according to RFC 2445, the newline followed by a space is the correct way to split long lines, so you'll probably see a lot of this in scanning FREEBUSY data.
As Nathan suggests, an NSScanner
may be all you need if the data you're expecting will be reasonably consistent. There are a number of vagaries in iCalendar, though, so I often find myself using libical to parse ics info. An quick-and-dirty example of parsing this data using libical:
NSString *caldata = @"BEGIN:VCALENDAR\nVERS....etc";
icalcomponent *root = icalparser_parse_string([caldata cStringUsingEncoding:NSUTF8StringEncoding]);
if (root) {
icalcomponent *c = icalcomponent_get_first_component(root, ICAL_VFREEBUSY_COMPONENT);
while (c) {
icalproperty *p = icalcomponent_get_first_property(c, ICAL_FREEBUSY_PROPERTY);
while (p) {
icalvalue *v = icalproperty_get_value(p);
// This gives: 20090605T170000Z/20090605T200000Z
// (note that stringWithCString is deprecated)
NSLog(@"FREEBUSY Value: %@", [NSString stringWithCString:icalvalue_as_ical_string(v)]);
icalparameter *m = icalproperty_get_first_parameter(p, ICAL_FBTYPE_PARAMETER);
while (m) {
// This gives: FBTYPE=BUSY
NSLog(@"Parameter: %@", [NSString stringWithCString:icalparameter_as_ical_string(m)]);
m = icalproperty_get_next_parameter(p, ICAL_FBTYPE_PARAMETER);
}
p = icalcomponent_get_next_property(c, ICAL_FREEBUSY_PROPERTY);
}
c = icalcomponent_get_next_component(root, ICAL_VFREEBUSY_COMPONENT);
}
icalcomponent_free(root);
}
Documentation for libical is in the project download itself (see UsingLibical.txt
). There's also this lovely tutorial on shipping libical in your application bundle.
Take a look at NSScanner.