使用Objective-C解析VCALENDAR(ics) [英] Parse VCALENDAR (ics) with Objective-C

问题描述

我正在寻找一种使用Objective-C解析VCALENDAR数据的简便方法.我只关心的是FREEBUSY数据(见下文):

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

我尝试使用componentsSeparatedByString:@"\ n"对其进行解析，但是部分FREEBUSY数据中存在\ n，导致其无法正确解析.

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.

我想念一些容易的事吗?

Is there something easy that I'm missing?

推荐答案

FREEBUSY数据中间的\n是iCalendar规范的一部分；根据 RFC 2445 ，换行符后接空格是分割的正确方法行很长，因此在扫描忙"数据时您可能会看到很多这样的信息.

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.

正如Nathan所建议的，如果您期望的数据是合理一致的，那么NSScanner可能就是您所需要的.不过，iCalendar中有很多变化莫测的东西，所以我经常发现自己使用 libical 来解析ics信息.一个使用libical解析此数据的简单示例:

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);
}

libical的文档在项目下载本身中(请参见UsingLibical.txt).还有一个关于如何在您的应用程序捆绑包中发布 libical .

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.

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