Profile of DateTime/TimeZone/Local.pm

Filename	/usr/share/perl5/DateTime/TimeZone/Local.pm
Statements	Executed 0 statements in 47µs

Line	State ments	Time on line	Code
1			package DateTime::TimeZone::Local;
2			$DateTime::TimeZone::Local::VERSION = '1.75';
3			use strict;
4			use warnings;
5
6			use Class::Load qw( is_class_loaded load_class try_load_class );
7			use DateTime::TimeZone;
8			use File::Spec;
9
10			sub TimeZone {
11			my $class = shift;
12
13			my $subclass = $class->_load_subclass();
14
15	1	9µs	for my $meth ( $subclass->Methods() ) {
16	1	28µs	my $tz = $subclass->$meth();
17
18			return $tz if $tz;
19			}
20
21			die "Cannot determine local time zone\n";
22			}
23
24			{
25			# Stolen from File::Spec. My theory is that other folks can write
26			# the non-existent modules if they feel a need, and release them
27			# to CPAN separately.
28			my %subclass = (
29			MSWin32 => 'Win32',
30			VMS => 'VMS',
31			MacOS => 'Mac',
32			os2 => 'OS2',
33			epoc => 'Epoc',
34			NetWare => 'Win32',
35			symbian => 'Win32',
36			dos => 'OS2',
37			android => 'Android',
38			cygwin => 'Unix',
39			);
40
41			sub _load_subclass {
42			my $class = shift;
43
44			my $os_name = $subclass{$^O} \|\| $^O;
45			my $subclass = $class . '::' . $os_name;
46
47			return $subclass if is_class_loaded($subclass);
48
49			return $subclass if try_load_class($subclass);
50
51			$subclass = $class . '::Unix';
52
53			load_class($subclass);
54
55			return $subclass;
56			}
57			}
58
59			sub FromEnv {
60			my $class = shift;
61
62	1	10µs	foreach my $var ( $class->EnvVars() ) {
63			if ( $class->_IsValidName( $ENV{$var} ) ) {
64			my $tz;
65			{
66			local $@;
67			local $SIG{__DIE__};
68			$tz = eval { DateTime::TimeZone->new( name => $ENV{$var} ) };
69			}
70			return $tz if $tz;
71			}
72			}
73
74			return;
75			}
76
77			sub _IsValidName {
78			shift;
79
80			return 0 unless defined $_[0];
81			return 0 if $_[0] eq 'local';
82
83			return $_[0] =~ m{^[\w/\-\+]+$};
84			}
85
86			1;
87
88			# ABSTRACT: Determine the local system's time zone
89
90			__END__
91
92			=pod
93
94			=encoding UTF-8
95
96			=head1 NAME
97
98			DateTime::TimeZone::Local - Determine the local system's time zone
99
100			=head1 VERSION
101
102			version 1.75
103
104			=head1 SYNOPSIS
105
106			my $tz = DateTime::TimeZone->new( name => 'local' );
107
108			my $tz = DateTime::TimeZone::Local->TimeZone();
109
110			=head1 DESCRIPTION
111
112			This module provides an interface for determining the local system's
113			time zone. Most of the functionality for doing this is in OS-specific
114			subclasses.
115
116			=head1 USAGE
117
118			This class provides the following methods:
119
120			=head2 DateTime::TimeZone::Local->TimeZone()
121
122			This attempts to load an appropriate subclass and asks it to find the
123			local time zone. This method is called by when you pass "local" as the
124			time zone name to C<< DateTime:TimeZone->new() >>.
125
126			If your OS is not explicitly handled, you can create a module with a
127			name of the form C<DateTime::TimeZone::Local::$^O>. If it exists, it
128			will be used instead of falling back to the Unix subclass.
129
130			If no OS-specific module exists, we fall back to using the Unix
131			subclass.
132
133			See L<DateTime::TimeZone::Local::Unix>,
134			L<DateTime::TimeZone::Local::Win32>, and
135			L<DateTime::TimeZone::Local::VMS> for OS-specific details.
136
137			=head1 SUBCLASSING
138
139			If you want to make a new OS-specific subclass, there are several
140			methods provided by this module you should know about.
141
142			=head2 $class->Methods()
143
144			This method should be provided by your class. It should provide a list
145			of methods that will be called to try to determine the local time
146			zone.
147
148			Each of these methods is expected to return a new
149			C<DateTime::TimeZone> object if it determines the time zone.
150
151			=head2 $class->FromEnv()
152
153			This method tries to find a valid time zone in an C<%ENV> value. It
154			calls C<< $class->EnvVars() >> to determine which keys to look at.
155
156			To use this from a subclass, simply return "FromEnv" as one of the
157			items from C<< $class->Methods() >>.
158
159			=head2 $class->EnvVars()
160
161			This method should be provided by your subclass. It should return a
162			list of env vars to be checked by C<< $class->FromEnv() >>.
163
164			=head2 $class->_IsValidName($name)
165
166			Given a possible time zone name, this returns a boolean indicating
167			whether or not the name looks valid. It always return false for
168			"local" in order to avoid infinite loops.
169
170			=head1 EXAMPLE SUBCLASS
171
172			Here is a simple example subclass:
173
174			package DateTime::TimeZone::SomeOS;
175
176			use strict;
177			use warnings;
178
179			use base 'DateTime::TimeZone::Local';
180
181
182			sub Methods { qw( FromEnv FromEther ) }
183
184			sub EnvVars { qw( TZ ZONE ) }
185
186			sub FromEther
187			{
188			my $class = shift;
189
190			...
191			}
192
193			=head1 AUTHOR
194
195			Dave Rolsky <autarch@urth.org>
196
197			=head1 COPYRIGHT AND LICENSE
198
199			This software is copyright (c) 2014 by Dave Rolsky.
200
201			This is free software; you can redistribute it and/or modify it under
202			the same terms as the Perl 5 programming language system itself.
203
204			=cut