#
# Here's the collected and slightly reoorded code from the article,
# not the complete application, as that's a tad more complicated,
# but enough to run if given appropriate data files, which will be
# left as an exercise for the reader.
# Current weather data
package Z::Weather;
use IO::All;
use DateTime;
use base qw(Class::Accessor);
Z::Weather->mk_accessors( qw(time temp pressure wind dir) );
sub from_file {
my $class = shift;
my $io = io(shift);
my @recs = ();
while (my $line = $io->readline()) {
chomp($line);
push @recs, $class->_line($line);
}
return @recs;
}
sub _line {
my ($class, $line) = @_;
my @vals = split /\s+/, $line;
# extract time fields and turn into DateTime object
my($y, $m, $d, $h, $min)
= $line =~ /^(\d{4}) (\d\d) (\d\d) (\d\d) (\d\d)/;
my $t = DateTime->new(year=>$y,month=>$m,day=>$d,hour=>$h,minute=>$min);
# return a new Z::Weather record, using the magic new() method
return $class->new({time => $t,
temp => $vals[5],
pressure => $vals[6],
wind => $vals[7],
dir => $vals[8], });
}
package Z::Mast;
use IO::All;
use DateTime;
use base qw(Class::Accessor);
# map height of reading to offsets in binary record
our %heights = qw(1 24 2 28 4 32 8 36 15 40 30 44);
use constant MAST_EPOCH => 2082844800;
Z::Mast->mk_accessors(qw(time values));
sub from_file {
my $class = shift;
my $io = io(shift);
my ($rec, @recs);
while ($io->read($rec, 62) == 62) {
push @recs, $class->_record($rec);
}
return @recs;
}
sub _record {
my ($class, $rec) = @_;
# extract the time as a 4 byte network order integer, and correct epoch
my $crazy_time = unpack("N", $rec);
my $time = DateTime->from_epoch(epoch=> $crazy_time - (MAST_EPOCH));
# then a series of (speed, dir) 2 byte pairs further into the record
my @vals;
foreach my $offset (sort values %heights) {
my ($speed, $dir) = unpack("nn", substr($rec, $offset));
push @vals,
Z::Mast::Level->new({wind=>$speed*100,
dir => $dir*100,
level=>$heights{$offset}});
}
return $class->new({time => $time,
values => \@vals});
}
package Z::Mast::Level;
use base qw(Class::Accessor);
Z::Mast::Level->mk_accessors(qw(wind dir level));
package main;
use strict;
use warnings;
use Template;
use DateTime;
use DateTime::Duration;
use Chart::Lines;
my $x_size = 500;
my $y_size = 300;
my @weather_records = Z::Weather->from_file('weather.data.dat');
my @mast_values = Z::Mast->from_file('mast.data.dat');
my $template = Template->new();
print "Content-type: text/html\n\n";
$template->process(\*DATA, {
now => $weather_records[-1],
records => \@weather_records,
})
|| die "Could not process template: ".$template->error()."\n";
## pngs
my $now = DateTime->now();
my $age = DateTime::Duration->new(hours => 3);
@mast_values = grep { $_->time + $age > $now } @mast_values;
my $chart = Chart::Lines->new($x_size, $y_size);
$chart->set(
legend => 'none',
xy_plot => 'true',
grey_background => 0,
y_label => 'Wind kts',
x_label => 'Hours ago',
colors => {
y_label => [0xff, 0xee, 0xee],
text => [0xff,0xee,0xff],
dataset0 => [0xff,0,0],
dataset1 => [0,0xff,0xff],
dataset2 => [0,0,0xff],
background => [0x55, 0x00, 0x55],
},
);
my @labels = map {($now->epoch - $_->time->epoch) / 60} @mast_values;
$chart->png("mast_chart.png",
[ \@labels,
[map {$_->values()->[0]->wind} @mast_values],
[map {$_->values()->[1]->wind} @mast_values],
[map {$_->values()->[2]->wind} @mast_values],
]);
## template
__END__
Weather
Latest weather data at [% now.time %]Z
T: [% now.temp %] °C
P: [% now.pressure %] kPa
W: [% now.wind %] kts
D: [% now.dir %] °
| Time | Temp | Wind |
|---|
[% FOREACH rec IN records %]
| [% rec.time %] |
[% rec.temp %] |
[% rec.wind %] |
[% END %]