Badger::Class::Vars - class module for defining package variables
package My::Module; # simple pre-declaration of variables use Badger::Class::Vars '$FOO @BAR %BAZ'; # pre-declaration with values use Badger::Class::Vars '$FOO' => 10, '@BAR' => [20, 30, 40], '%BAZ' => { x => 100, y => 200 }; # via Badger::Class use Badger::Class vars => '$FOO @BAR %BAZ'; # via Badger::Class with values use Badger::Class vars => { '$FOO' => 10, '@BAR' => [20, 30, 40], '%BAZ' => { x => 100, y => 200 }, };
This module allows you to pre-declare and optionally, define values for package variables. It can be used directly, or via the vars export hook in Badger::Class.
# using the module directly use Badger::Class::Vars '$FOO @BAR %BAZ'; # using it via Badger::Class use Badger::Class vars => '$FOO @BAR %BAZ';
In the simple case, it works just like the vars.pm module in pre-declaring the variables named.
vars.pm
Unlike vars.pm, this method will only define scalar, list and hash package variables (e.g. $SOMETHING, @SOMETHING or %SOMETHING).
$SOMETHING
@SOMETHING
%SOMETHING
If you want to define subroutines/methods then you can use the Badger::Class::Methods module, or the methods import hook or methods() method in Badger::Class. If you want to define a glob reference then you're already operating in Wizard Mode and you don't need our help.
If you don't specify a leading sigil (i.e. $, @ or %) then it will default to $ and create a scalar variable.
$
@
%
use Badger::Class vars => 'FOO BAR BAZ'; # declares $FOO, $BAR and $BAZ
You can also use a reference to a hash array to define values for variables.
use Badger::Class vars => { # Equivalent code: '$FOO' => 42, # our $FOO = 25 '@WIZ' => [100, 200, 300], # our @WIZ = (100, 200, 300) '%WOZ' => {ping => 'pong'}, # our %QOZ = (ping => 'pong') };
Scalar package variables can be assigned any scalar value or a reference to some other data type. Again, the leading $ is optional on the variable names. Note the difference in the equivalent code - this time we end up with scalar variables and references exclusively.
use Badger::Class vars => { # Equivalent code: FOO => 42, # our $FOO = 42 BAR => [100, 200, 300], # our $BAR = [100, 200, 300] BAZ => {ping => 'pong'}, # our $BAZ = {ping => 'pong'} HAI => sub { # our $HAI = sub { ... } 'Hello ' . (shift || 'World') }, };
You can also assign any kind of data to a package list variable. If it's not already a list reference then the value will be treated as a single item list.
use Badger::Class vars => { # Equivalent code: '@FOO' => 42, # our @FOO = (42) };
This method defines variable in the $target package. It is usually called automatically when the module is loaded via use.
$target
use
The $vars can be specified as a single text string of whitespace delimited symbols or by reference to a list of individual symbols. The variables will be declared but undefined.
$vars
# single string Badger::Class::Vars->vars( 'My::Package', '$FOO, @BAR, %BAZ' ); # list reference Badger::Class::Vars->vars( 'My::Package', ['$FOO', '@BAR', '%BAZ'] );
Use a reference to a hash array if you want to provide values for the variables.
# hash reference Badger::Class::Vars->vars( 'My::Package', { '$FOO' => 10, '@BAR' => [20, 30, 40], '%BAZ' => { x => 100, y => 200 }, } );
Andy Wardley http://wardley.org/
Copyright (C) 2008-2009 Andy Wardley. All Rights Reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
To install Badger, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Badger
CPAN shell
perl -MCPAN -e shell install Badger
For more information on module installation, please visit the detailed CPAN module installation guide.