DateTime::TimeZone::Alias - Create aliases for DateTime timezones
use DateTime::TimeZone::Alias Hawaii => 'Pacific/Honolulu', EST => 'Australia/Melbourne'; or DateTime::TimeZone::Alias->add( Fun => 'America/Tijuana', %hash ); or DateTime::TimeZone::Alias->set( Pain => 'America/Dawson_Creek', %hash ); DateTime::TimeZone::Alias->set( boat => 'floating' ); DateTime::TimeZone::Alias->set( home => 'local' ); DateTime::TimeZone::Alias->set( lulu => 'Z' ); DateTime::TimeZone::Alias->set( cut => 'UTC' ); DateTime::TimeZone::Alias->set( nowhere => '-09:30' ); or DateTime::TimeZone::Alias->remove( qw( Hawaii EST Pain Fun ) ); or DateTime::TimeZone::Alias->value( 'EST' ); or DateTime::TimeZone::Alias->is_defined( 'Hawaii' ) DateTime::TimeZone::Alias->is_alias( 'EST' ) DateTime::TimeZone::Alias->is_timezone( 'Antarctica/Vostok' ) or DateTime::TimeZone::Alias->aliases DateTime::TimeZone::Alias->timezones
Creates and destroys aliases for DateTime timezones. This module violates the encapsulation of the DateTime internals. User _Beware_.
Accepts a hash representing an alias and the timezone it should map too. Import has the exact same behaviors as the set method.
set
set( alias => timezone, ... )
Accepts a hash representing an alias and the timezone it should map too. If an invalid timezone value or no parameters are passed an exception is thrown. It is possible to create an alias to another alias. This method will redefine an existing alias or add a new alias that overrides an existing timezone.
What may be aliased:
aliases floating local OffsetOnly Olson time zones UTC Z
add( alias => timezone, ... )
Accepts a hash representing an alias and the timezone it should map too. If an invalid timezone value or no parameters are passed an exception is thrown. It is possible to create an alias to another alias. This method will _not_ redefine an existing alias or allow you remap a timezone. For redefinitions see the set method.
remove( alias, ... )
Accepts a list of aliases to be removed. If an the name of an aliases that doesn't exist is passed in then an exception is thrown. It's important to note that you can remove aliases but not timezones. However, a redefined timezone is actually an alias and can be removed.
value( $str )
If $str is a known alias then the timezone being aliased is returned, otherwise undef.
is_defined( $str )
If $str is a known timezone or alias this method returns 1, otherwise undef is returned.
is_alias( $str )
If $str is a known alias this method returns 1, otherwise undef is returned.
is_timezone( $str )
If $str is a known timezone this method returns 1, otherwise undef is returned.
aliases
In list context a hash of all known aliases and their values is returned. In scalar context a reference to a hash is returned.
timezones
In list context an array of all known timezones is returned. In scalar context a reference to an array is returned.
Multiple use DateTime::TimeZone::Alias statements in the same package may not have the desired result if attempting to redefine existing aliases. If you want to redefine an alias use the set method instead.
use DateTime::TimeZone::Alias
You can _not_ create circular aliases. E.g.
# TSH actually points to value of HST - 'Pacific/Honolulu' # if HST wasn't already defined this would be an exception DateTime::TimeZone::Alias->set( TSH => HST ); # HST still points to 'Pacific/Honolulu' DateTime::TimeZone::Alias->set( HST => TSH );
Sorry - no evil here, move along.
It's important to remember that aliases are global in scope. E.g.
package Foo; DateTime::TimeZone::Alias->set( EST => 'US/Eastern' ); Bar->bar(); # this will fail because EST is no longer defined my $dt = DateTime->now( time_zone => 'EST' ); package Bar; sub bar { DateTime::TimeZone::Alias->set( EST => 'US/Eastern' ); . . DateTime::TimeZone::Alias->remove( qw( EST ) ); }
There are many possible ways to avoid this trap. The best solution is to simply not write code like this. If you insist on this style then you can try one of the suggested work arounds.
Sometimes DateTime::TimeZone::Alias may not be the best solution to your problem. Particularly if your in an environment that has poor sand-boxing such as mod_perl. E.g.
sand-boxing
mod_perl
use constant EST => 'US/Eastern'; or sub EST () { 'US/Eastern' } . . my $dt = DateTime->new( %params, time_zone => EST );
This probably isn't thread safe. E.g.
sub bar { my $my_alias = DateTime::TimeZone::Alias->value( 'EST' ); DateTime::TimeZone::Alias->set( EST => 'US/Eastern' ); . . DateTime::TimeZone::Alias->set( EST => $my_alias ); }
If $my_alias is undefined then the set will fail as an alias must point to a valid timezone.
$my_alias
The aliases and timezones methods preserve encapsulation by returning a reference to a copy of the internal data structures instead of a direct reference.
Ben Bennett (BBENNETT) for a bug report, some API suggestions, documentation suggestions, and being so darn enthusiastic. (not necessary in that order)
Everyone at the DateTime Asylum.
Asylum
Support for this module is provided via the datetime@perl.org email list. See http://lists.perl.org/ for more details.
Joshua Hoblitt <jhoblitt@cpan.org>
Copyright (c) 2003-2010 Joshua Hoblitt. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included with this module.
datetime@perl.org mailing list
http://datetime.perl.org/
To install DateTime::TimeZone::Alias, copy and paste the appropriate command in to your terminal.
cpanm
cpanm DateTime::TimeZone::Alias
CPAN shell
perl -MCPAN -e shell install DateTime::TimeZone::Alias
For more information on module installation, please visit the detailed CPAN module installation guide.