IkiWiki/Plugin/calendar.pm



#! /usr/bin/perl
# Copyright (c) 2006, 2007 Manoj Srivastava <srivasta@debian.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

require 5.002;
package IkiWiki::Plugin::calendar;

use warnings;
use strict;
use IkiWiki 3.00;
use Time::Local;
use POSIX;

my $time=time;
my @now=localtime($time);

sub import {
    hook(type => "getsetup", id => "calendar", call => \&getsetup);
    hook(type => "needsbuild", id => "calendar", call => \&needsbuild);
    hook(type => "preprocess", id => "calendar", call => \&preprocess);
}

sub getsetup () {
    return
        plugin => {
            safe => 1,
            rebuild => undef,
        },
        archivebase => {
            type => "string",
            example => "archives",
            description => "base of the archives hierarchy",
            safe => 1,
            rebuild => 1,
        },
}

sub is_leap_year (@) {
    my %params=@_;
    return ($params{year} % 4 == 0 && (($params{year} % 100 != 0) || $params{year} % 400 == 0));
}

sub month_days {
    my %params=@_;
    my $days_in_month = (31,28,31,30,31,30,31,31,30,31,30,31)[$params{month}-1];
    if ($params{month} == 2 && is_leap_year(%params)) {
        $days_in_month++;
    }
    return $days_in_month;
}

sub format_month (@) {
    my %params=@_;

    my %linkcache;
    foreach my $p (pagespec_match_list($params{page}, $params{pages},
                # add presence dependencies to update
                # month calendar when pages are added/removed
                deptype => deptype("presence"))) {
        my $mtime = $IkiWiki::pagectime{$p};
        my @date  = localtime($mtime);
        my $mday  = $date[3];
        my $month = $date[4] + 1;
        my $year  = $date[5] + 1900;
        my $mtag  = sprintf("%02d", $month);

        # Only one posting per day is being linked to.
        $linkcache{"$year/$mtag/$mday"} = $p;
    }
        
    my $pmonth = $params{month} - 1;
    my $nmonth = $params{month} + 1;
    my $pyear  = $params{year};
    my $nyear  = $params{year};

    # Adjust for January and December
    if ($params{month} == 1) {
        $pmonth = 12;
        $pyear--;
    }
    if ($params{month} == 12) {
        $nmonth = 1;
        $nyear++;
    }

    # Add padding.
    $pmonth=sprintf("%02d", $pmonth);
    $nmonth=sprintf("%02d", $nmonth);

    my $calendar="\n";

    # When did this month start?
    my @monthstart = localtime(timelocal(0,0,0,1,$params{month}-1,$params{year}-1900));

    my $future_dom = 0;
    my $today      = 0;
    if ($params{year} == $now[5]+1900 && $params{month} == $now[4]+1) {
        $future_dom = $now[3]+1;
        $today      = $now[3];
    }

    # Find out month names for this, next, and previous months
    my $monthname=POSIX::strftime("%B", @monthstart);
    my $pmonthname=POSIX::strftime("%B", localtime(timelocal(0,0,0,1,$pmonth-1,$pyear-1900)));
    my $nmonthname=POSIX::strftime("%B", localtime(timelocal(0,0,0,1,$nmonth-1,$nyear-1900)));

    my $archivebase = 'archives';
    $archivebase = $config{archivebase} if defined $config{archivebase};
    $archivebase = $params{archivebase} if defined $params{archivebase};
  
    # Calculate URL's for monthly archives.
    my ($url, $purl, $nurl)=("$monthname",'','');
    if (exists $pagesources{"$archivebase/$params{year}/$params{month}"}) {
        $url = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$params{year}/".$params{month},
            noimageinline => 1,
            linktext => " $monthname ");
    }
    add_depends($params{page}, "$archivebase/$params{year}/$params{month}",
        deptype("presence"));
    if (exists $pagesources{"$archivebase/$pyear/$pmonth"}) {
        $purl = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$pyear/$pmonth",
            noimageinline => 1,
            linktext => " \&larr ");
    }
    add_depends($params{page}, "$archivebase/$pyear/$pmonth",
        deptype("presence"));
    if (exists $pagesources{"$archivebase/$nyear/$nmonth"}) {
        $nurl = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$nyear/$nmonth",
            noimageinline => 1,
            linktext => " \&rarr ");
    }
    add_depends($params{page}, "$archivebase/$nyear/$nmonth",
        deptype("presence"));

    # Start producing the month calendar
    $calendar=<<EOF;
<table class="month-calendar">
    <caption class="month-calendar-head">
    $purl
    $url
    $nurl
    </caption>
    <tr>
EOF

    # Suppose we want to start the week with day $week_start_day
    # If $monthstart[6] == 1
    my $week_start_day = $params{week_start_day};

    my $start_day = 1 + (7 - $monthstart[6] + $week_start_day) % 7;
    my %downame;
    my %dowabbr;
    for my $dow ($week_start_day..$week_start_day+6) {
        my @day=localtime(timelocal(0,0,0,$start_day++,$params{month}-1,$params{year}-1900));
        my $downame = POSIX::strftime("%A", @day);
        my $dowabbr = POSIX::strftime("%a", @day);
        $downame{$dow % 7}=$downame;
        $dowabbr{$dow % 7}=$dowabbr;
        $calendar.= qq{\t\t<th class="month-calendar-day-head $downame">$dowabbr</th>\n};
    }

    $calendar.=<<EOF;
    </tr>
EOF

    my $wday;
    # we start with a week_start_day, and skip until we get to the first
    for ($wday=$week_start_day; $wday != $monthstart[6]; $wday++, $wday %= 7) {
        $calendar.=qq{\t<tr>\n} if $wday == $week_start_day;
        $calendar.=qq{\t\t<td class="month-calendar-day-noday $downame{$wday}">&nbsp;</td>\n};
    }

    # At this point, either the first is a week_start_day, in which case
    # nothing has been printed, or else we are in the middle of a row.
    for (my $day = 1; $day <= month_days(year => $params{year}, month => $params{month});
         $day++, $wday++, $wday %= 7) {
        # At tihs point, on a week_start_day, we close out a row,
        # and start a new one -- unless it is week_start_day on the
        # first, where we do not close a row -- since none was started.
        if ($wday == $week_start_day) {
            $calendar.=qq{\t</tr>\n} unless $day == 1;
            $calendar.=qq{\t<tr>\n};
        }
        
        my $tag;
        if (defined $linkcache{"$params{year}/$params{month}/$day"}) {
            if ($day == $today) {
                $tag='month-calendar-day-this-day';
            }
            else {
                $tag='month-calendar-day-link';
            }
            $calendar.=qq{\t\t<td class="$tag $downame{$wday}">};
            $calendar.=htmllink($params{page}, $params{destpage}, 
                $linkcache{"$params{year}/$params{month}/$day"},
                noimageinline => 1,
                "linktext" => "$day");
            $calendar.=qq{</td>\n};
        }
        else {
            if ($day == $today) {
                $tag='month-calendar-day-this-day';
            }
            elsif ($day == $future_dom) {
                $tag='month-calendar-day-future';
            }
            else {
                $tag='month-calendar-day-nolink';
            }
            $calendar.=qq{\t\t<td class="$tag $downame{$wday}">$day</td>\n};
        }
    }

    # finish off the week
    for (; $wday != $week_start_day; $wday++, $wday %= 7) {
        $calendar.=qq{\t\t<td class="month-calendar-day-noday $downame{$wday}">&nbsp;</td>\n};
    }
    $calendar.=<<EOF;
    </tr>
</table>
EOF

    return $calendar;
}

sub format_year (@) {
    my %params=@_;
        
    my $calendar="\n";
    
    my $pyear = $params{year}  - 1;
    my $nyear = $params{year}  + 1;

    my $future_month = 0;
    $future_month = $now[4]+1 if ($params{year} == $now[5]+1900);

    my $archivebase = 'archives';
    $archivebase = $config{archivebase} if defined $config{archivebase};
    $archivebase = $params{archivebase} if defined $params{archivebase};

    # calculate URL's for previous and next years
    my ($url, $purl, $nurl)=("$params{year}",'','');
    if (exists $pagesources{"$archivebase/$params{year}"}) {
        $url = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$params{year}",
            noimageinline => 1,
            linktext => "$params{year}");
    }
    add_depends($params{page}, "$archivebase/$params{year}", deptype("presence"));
    if (exists $pagesources{"$archivebase/$pyear"}) {
        $purl = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$pyear",
            noimageinline => 1,
            linktext => "\&larr;");
    }
    add_depends($params{page}, "$archivebase/$pyear", deptype("presence"));
    if (exists $pagesources{"$archivebase/$nyear"}) {
        $nurl = htmllink($params{page}, $params{destpage}, 
            "$archivebase/$nyear",
            noimageinline => 1,
            linktext => "\&rarr;");
    }
    add_depends($params{page}, "$archivebase/$nyear", deptype("presence"));

    # Start producing the year calendar
    $calendar=<<EOF;
<table class="year-calendar">
    <caption class="year-calendar-head">
    $purl
    $url
    $nurl
    </caption>
    <tr>
        <th class="year-calendar-subhead" colspan="$params{months_per_row}">Months</th>
    </tr>
EOF

    for (my $month = 1; $month <= 12; $month++) {
        my @day=localtime(timelocal(0,0,0,15,$month-1,$params{year}-1900));
        my $murl;
        my $monthname = POSIX::strftime("%B", @day);
        my $monthabbr = POSIX::strftime("%b", @day);
        $calendar.=qq{\t<tr>\n}  if ($month % $params{months_per_row} == 1);
        my $tag;
        my $mtag=sprintf("%02d", $month);
        if ($month == $params{month}) {
            if ($pagesources{"$archivebase/$params{year}/$mtag"}) {
                $tag = 'this_month_link';
            }
            else {
                $tag = 'this_month_nolink';
            }
        }
        elsif ($pagesources{"$archivebase/$params{year}/$mtag"}) {
            $tag = 'month_link';
        } 
        elsif ($future_month && $month >= $future_month) {
            $tag = 'month_future';
        } 
        else {
            $tag = 'month_nolink';
        }

        if ($pagesources{"$archivebase/$params{year}/$mtag"}) {
            $murl = htmllink($params{page}, $params{destpage}, 
                "$archivebase/$params{year}/$mtag",
                noimageinline => 1,
                linktext => "$monthabbr");
            $calendar.=qq{\t<td class="$tag">};
            $calendar.=$murl;
            $calendar.=qq{\t</td>\n};
        }
        else {
            $calendar.=qq{\t<td class="$tag">$monthabbr</td>\n};
        }
        add_depends($params{page}, "$archivebase/$params{year}/$mtag",
            deptype("presence"));

        $calendar.=qq{\t</tr>\n} if ($month % $params{months_per_row} == 0);
    }

    $calendar.=<<EOF;
</table>
EOF

    return $calendar;
}

sub preprocess (@) {
    my %params=@_;

    my $thisyear=1900 + $now[5];
    my $thismonth=1 + $now[4];

    $params{pages} = "*"            unless defined $params{pages};
    $params{type}  = "month"        unless defined $params{type};
    $params{week_start_day} = 0     unless defined $params{week_start_day};
    $params{months_per_row} = 3     unless defined $params{months_per_row};
    $params{year}  = $thisyear  unless defined $params{year};
    $params{month} = $thismonth unless defined $params{month};

    $params{month} = sprintf("%02d", $params{month});
            
    if ($params{type} eq 'month' && $params{year} == $thisyear
        && $params{month} == $thismonth) {
        # calendar for current month, updates next midnight
        $pagestate{$params{destpage}}{calendar}{nextchange}=($time
            + (60 - $now[0])        # seconds
            + (59 - $now[1]) * 60       # minutes
            + (23 - $now[2]) * 60 * 60  # hours
        );
    }
    elsif ($params{type} eq 'month' &&
           (($params{year} == $thisyear && $params{month} > $thismonth) ||
            $params{year} > $thisyear)) {
        # calendar for upcoming month, updates 1st of that month
        $pagestate{$params{destpage}}{calendar}{nextchange}=
            timelocal(0, 0, 0, 1, $params{month}-1, $params{year});
    }
    elsif ($params{type} eq 'year' && $params{year} == $thisyear) {
        # calendar for current year, updates 1st of next month
        $pagestate{$params{destpage}}{calendar}{nextchange}=
            timelocal(0, 0, 0, 1, $thismonth+1-1, $params{year});
    }
    elsif ($params{type} eq 'year' && $params{year} > $thisyear) {
        # calendar for upcoming year, updates 1st of that year
        $pagestate{$params{destpage}}{calendar}{nextchange}=
            timelocal(0, 0, 0, 1, 1-1, $params{year});
    }
    else {
        # calendar for past month or year, does not need
        # to update any more
        delete $pagestate{$params{destpage}}{calendar};
    }

    # Calculate month names for next month, and previous months
    my $calendar="";
    if ($params{type} eq 'month') {
        $calendar=format_month(%params);
    }
    elsif ($params{type} eq 'year') {
        $calendar=format_year(%params);
    }

    return "\n<div><div class=\"calendar\">$calendar</div></div>\n";
} #}}

sub needsbuild (@) {
    my $needsbuild=shift;
    foreach my $page (keys %pagestate) {
        if (exists $pagestate{$page}{calendar}{nextchange}) {
            if ($pagestate{$page}{calendar}{nextchange} <= $time) {
                # force a rebuild so the calendar shows
                # the current day
                push @$needsbuild, $pagesources{$page};
            }
            if (exists $pagesources{$page} && 
                grep { $_ eq $pagesources{$page} } @$needsbuild) {
                # remove state, will be re-added if
                # the calendar is still there during the
                # rebuild
                delete $pagestate{$page}{calendar};
            }
        }
    }
}

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