Create ICS with objective C - objective-c

Question

I am writing an app for students at my university. At this point I want to export the lessons in the schedule as an ics-file. I have wrote something that works with csv-files, but now I want the same for ics.
The problem is that iCal at my Mac doesn't want the in-app-created ics-files from this code:
-(NSURL*)getFileUrl
{
NSString *docsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
NSString *filePath = [docsPath stringByAppendingPathComponent:[NSString stringWithFormat:#"Stundenplan-%#.ics", _MatrNr]];
NSURL *fileUrl = [NSURL fileURLWithPath:filePath];
NSError *error = nil;
[[self getICSData] writeToURL:fileUrl atomically:YES];
if (error) {
NSLog(#"Error while writing to File: %#", [error localizedDescription]);
}
return fileUrl;
}
-(NSData*)getICSData
{
NSMutableString *erg = [[NSMutableString alloc] init];
NSDate *aktDatum = [NSDate date];
[erg appendString:[NSString stringWithFormat:#"BEGIN:VCALENDAR\nVERSION:2.0\nPRODID:-//www.htw-dresden.de//iOS//DE\nMETHOD:PUBLISH\n"]];
for (Stunde *this in _daten) {
NSString *titel = [this.titel stringByReplacingOccurrencesOfString:#"," withString:#"\\, "];
NSString *dozent = [this.dozent stringByReplacingOccurrencesOfString:#"," withString:#"\\, "];
NSString *uuid = [[NSUUID UUID] UUIDString];
[erg appendString:[NSString stringWithFormat:#"BEGIN:VEVENT\nUID:%#\n", uuid]];
[erg appendString:[NSString stringWithFormat:#"DTSTART:%#T%#Z\n",[self nurTagFromDate:this.anfang], [self nurUhrzeigFromDate:this.anfang]]];
[erg appendString:[NSString stringWithFormat:#"DTEND:%#T%#Z\n",[self nurTagFromDate:this.ende], [self nurUhrzeigFromDate:this.ende]]];
[erg appendString:[NSString stringWithFormat:#"LAST-MODIFIED:%#T%#Z\nSEQUENCE:0\nSTATUS:CONFIRMED\n", [self nurTagFromDate:aktDatum], [self nurUhrzeigFromDate:aktDatum]]];
[erg appendString:[NSString stringWithFormat:#"SUMMARY:%#\nDESCRIPTION:%#\nLOCATION:%#\nEND:VEVENT\n", titel, dozent, this.raum]];
}
[erg appendString:#"END:VCALENDER"];
NSData *ret = [erg dataUsingEncoding:NSUTF8StringEncoding];
return ret;
}
In the getFileUrl I want to return a URL to the file created in there. This function calls the getICSData function that goes through my array (_daten) and creates for every Stunde object this ics-"code".
For help I have these NSDate formatting functions:
-(NSString*)nurTagFromDate:(NSDate*)date
{
NSDateFormatter *nurTag = [[NSDateFormatter alloc] init];
[nurTag setDateFormat:#"yyyyMMdd"];
return [nurTag stringFromDate:date];
}
-(NSString*)nurUhrzeigFromDate:(NSDate*)date
{
NSDateFormatter *nurTag = [[NSDateFormatter alloc] init];
[nurTag setDateFormat:#"HHmmss"];
return [nurTag stringFromDate:date];
}
As output I get something like this:
BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//www.htw-dresden.de//iOS//DE
METHOD:PUBLISH
BEGIN:VEVENT
UID:CCCAC9B3-E056-47E3-A63B-F2FE2C3BA454
DTSTART:20140318T111000Z
DTEND:20140318T124000Z
LAST-MODIFIED:20140429T182723Z
SEQUENCE:0
STATUS:CONFIRMED
SUMMARY:Internet-Technologien I
DESCRIPTION:Vogt\, J.
LOCATION:Z 254
END:VEVENT
.
.
.
END:VCALENDER
But the calendar app at my Mac don't want to open the file...
It would be great if some of you will have an Idea :)

Answer 1

Replace this line:
[erg appendString:#"END:VCALENDER"];
With this:
[erg appendString:#"END:VCALENDAR"];
Notice the typo in VCALENDAR.
You may find this iCal file validator useful.