Tie::iCal(3pm)

Tie::iCal3pm

Tie ical files to perl hashes.

Usage

        use Tie::iCal;
        
        tie %my_events, 'Tie::iCal', "mycalendar.ics" or die "Failed to tie file!\n";
        tie %your_events, 'Tie::iCal', "yourcalendar.ics" or die "Failed to tie file!\n";
        
        $my_events{"A-NEW-UNIQUE-ID"} = [
                'VEVENT',
                {
                        'SUMMARY' => 'Bastille Day Party',
                        'DTSTAMP' => '19970714T170000Z',
                        'DTEND' => '19970715T035959Z',
                }
        ];
        
        tie %our_events, 'Tie::iCal', "ourcalendar.ics" or die "Failed to tie file!\n";
        
        # assuming %my_events and %your_events
        # have no common keys (unless that's your intention)
        #
        while (my($uid,$event) = each(%my_events)) {
                $our_events{$uid} = $event;     
        }
        while (my($uid,$event) = each(%your_events)) {
                $our_events{$uid} = $event;
        }
        
        untie %our_events;
        untie %your_events;
        untie %my_events;

Version

This document describes version 0.14 released 1st September 2006.

Dependencies

        Tie::File

Overview

Tie::iCal represents an RFC2445 iCalendar file as a Perl hash. Each key in the hash represents an iCalendar component like VEVENT, VTODO or VJOURNAL. Each component in the file must have a unique UID property as specified in the RFC 2445. A file containing non-unique UIDs can be converted to have only unique UIDs (see samples/uniquify.pl).

The module makes very little effort in understanding what each iCalendar property means and concentrates on the format of the iCalendar file only.

File locking

The Tie::iCal object returned by tie can also be used to access the underlying Tie::File object. This is accessible via the 'A' class variable. This may be useful for file locking.

        my $ical = tie %events, 'Tie::iCal', "mycalendar.ics";
        $ical->{A}->flock;

Dates

The iCalendar specification uses a special format for dates. This module makes no effort in trying to interpret dates in this format. You should look at the Date::ICal module that can convert between Unix epoch dates and iCalendar date strings.

How Tie::iCal interprets iCal files

Tie::iCal interprets files by mapping iCal components into Perl hash keys and iCal content lines into various Perl arrays and hashes.

Components

An iCal component such as VEVENT, VTODO or VJOURNAL maps to a hash key:-

        BEGIN:VEVENT
        UID:a_unique_uid
        NAME1:VALUE1
        ..
        END:VEVENT

corresponds to

        $events{'a_unique_uid'} = ['VEVENT', {'NAME1' => 'VALUE1'}]

Subcomponents

An iCal subcomponent such as VALARM maps to a list of hash keys:-

        BEGIN:VALARM
        TRIGGER;VALUE=DURATION:-PT1S
        TRIGGER;VALUE=DURATION:-PT1S
        END:VALARM
        BEGIN:VALARM
        X-TIE-ICAL;VALUE=ANOTHER:HERE
        X-TIE-ICAL:HERE2
        X-TIE-ICAL-NAME:HERE2
        END:VALARM

corresponds to

        'VALARM' => [
                {
                        'TRIGGER' => [
                                [{'VALUE' => 'DURATION'},'-PT1S'],
                                [{'VALUE' => 'DURATION'},'-PT1S']
                        ]
                },
                {
                        'X-TIE-ICAL' => [
                                [{'VALUE' => 'ANOTHER'},'HERE'],
                                ['HERE2']
                        ],
                        'X-TIE-ICAL-NAME' => 'HERE2'
                }
        ]

To see how individual content lines are formed see below.

Content Lines

Once unfolded, a content line may look like:-

    NAME;PARAM1=PVAL1;PARAM2=PVAL2;...:VALUE1,VALUE2,...

having an equivalent perl data structure like: -

    'NAME' => [{'PARAM1'=>'PVAL1', 'PARAM2'=>'PVAL2', ..}, 'VALUE1', 'VALUE2', ..]

or

    NAME:VALUE1,VALUE2,...

having an equivalent perl data structure like: -

    'NAME' => ['VALUE1', 'VALUE2', ..]

or

    NAME:VALUE

having an equivalent perl data structure like: -

    'NAME' => 'VALUE'

An blank value is mapped from

        NAME:

to

        'NAME' => ''

Multiple contentlines with same name, i.e. FREEBUSY, ATTENDEE:-

    NAME;PARAM10=PVAL10;PARAM20=PVAL20;...:VALUE10,VALUE20,...
    NAME;PARAM11=PVAL11;PARAM21=PVAL21;...:VALUE11,VALUE21,...
    ...

having an equivalent perl data structure like: -

    'NAME' => [ 
        [{'PARAM10'=>'PVAL10', 'PARAM20'=>'PVAL20', ..}, 'VALUE10', 'VALUE20', ..],
        [{'PARAM11'=>'PVAL11', 'PARAM21'=>'PVAL21', ..}, 'VALUE11', 'VALUE21', ..],
        ...
    ]

or

    NAME:VALUE10,VALUE20,...
    NAME:VALUE11,VALUE21,...
    ...

having an equivalent perl data structure like: -

    'NAME' => [ 
        ['VALUE10', 'VALUE20', ..],
        ['VALUE11', 'VALUE21', ..],
        ...
    ]

or in a mixed form, i.e.

    NAME:VALUE10,VALUE20,...
    NAME;PARAM11=PVAL11;PARAM21=PVAL21:VALUE11,VALUE21,...
    NAME:VALUE12,VALUE22,...
    ...

having an equivalent perl data structure like: -

    'NAME' => [ 
        ['VALUE10', 'VALUE20', ..],
        [{'PARAM11'=>'PVAL11', 'PARAM21'=>'PVAL21', ..}, 'VALUE11', 'VALUE21', ..],
        ['VALUE12', 'VALUE22', ..],
        ...
    ]

Releases

10 releases since Debian 4.0 (Etch); the text changed 4 times.

  1. 4.0–6.0
  2. 7–8
  3. 9–10
  4. 11
  5. 12–13

Bugs

Property names are assumed not to be folded, i.e.

        DESCR
         IPTION:blah blah..

RRULE property does not support parameters.

Property names that begin with UID can potentially confuse this module.

Subcomponents such as VALARM must exist after any UID property.

Deleting events individually may leave non-RFC2445 compliant empty VCALENDAR objects.

Author

Blair Sutton, <mailto:[email protected]>, <http://www.numeninest.com/>

From libtie-ical-perl 0.15-4 in Debian 13 (Trixie). Parsed by carta from the page's man source.