package MooseX::LazyRequire;
BEGIN {
$MooseX::LazyRequire::AUTHORITY = 'cpan:FLORA';
}
{
$MooseX::LazyRequire::VERSION = '0.10';
}
# ABSTRACT: Required attributes which fail only when trying to use them
use Moose 0.94 ();
use Moose::Exporter;
use aliased 0.30 'MooseX::LazyRequire::Meta::Attribute::Trait::LazyRequire';
use namespace::autoclean;
my %metaroles = (
class_metaroles => {
attribute => [LazyRequire],
},
);
$metaroles{role_metaroles} = {
applied_attribute => [LazyRequire],
}
if $Moose::VERSION >= 1.9900;
Moose::Exporter->setup_import_methods(%metaroles);
1;
__END__
=pod
=encoding utf-8
=head1 NAME
MooseX::LazyRequire - Required attributes which fail only when trying to use them
=head1 SYNOPSIS
package Foo;
use Moose;
use MooseX::LazyRequire;
has foo => (
is => 'ro',
lazy_required => 1,
);
has bar => (
is => 'ro',
builder => '_build_bar',
);
sub _build_bar { shift->foo }
Foo->new(foo => 42); # succeeds, foo and bar will be 42
Foo->new(bar => 42); # succeeds, bar will be 42
Foo->new; # fails, neither foo nor bare were given
=head1 DESCRIPTION
This module adds a C<lazy_required> option to Moose attribute declarations.
The reader methods for all attributes with that option will throw an exception
unless a value for the attributes was provided earlier by a constructor
parameter or through a writer method.
=head1 CAVEATS
Prior to Moose 1.9900, roles didn't have an attribute metaclass, so this module can't
easily apply its magic to attributes defined in roles. If you want to use
C<lazy_required> in role attributes, you'll have to apply the attribute trait
yourself:
has foo => (
traits => ['LazyRequire'],
is => 'ro',
lazy_required => 1,
);
With Moose 1.9900, you can use this module in roles just the same way you can
in classes.
=for Pod::Coverage init_meta
=head1 AUTHORS
=over 4
=item *
Florian Ragwitz <rafl@debian.org>
=item *
Dave Rolsky <autarch@urth.org>
=back
=head1 COPYRIGHT AND LICENSE
This software is copyright (c) 2013 by Florian Ragwitz.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
=cut