package MooseX::UndefTolerant;
+
use strict;
use warnings;
-use Moose qw();
+use Moose 0.89 qw();
use Moose::Exporter;
-use Moose::Util::MetaRole;
use MooseX::UndefTolerant::Attribute;
+use MooseX::UndefTolerant::Class;
+use MooseX::UndefTolerant::Constructor;
+
+
+my %metaroles = (
+ class_metaroles => {
+ attribute => [ 'MooseX::UndefTolerant::Attribute' ],
+ }
+);
+if ( $Moose::VERSION < 1.9900 ) {
+ $metaroles{class_metaroles}{constructor} = [
+ 'MooseX::UndefTolerant::Constructor',
+ ];
+}
+else {
+ $metaroles{class_metaroles}{class} = [
+ 'MooseX::UndefTolerant::Class',
+ ];
+ $metaroles{role_metaroles} = {
+ applied_attribute => [
+ 'MooseX::UndefTolerant::Attribute',
+ ],
+ role => [
+ 'MooseX::UndefTolerant::Role',
+ ],
+ application_to_class => [
+ 'MooseX::UndefTolerant::ApplicationToClass',
+ ],
+ application_to_role => [
+ 'MooseX::UndefTolerant::ApplicationToRole',
+ ],
+ };
+}
-our $VERSION = '0.01';
-Moose::Exporter->setup_import_methods();
+Moose::Exporter->setup_import_methods(%metaroles);
-sub init_meta {
- my (undef, %options) = @_;
+1;
- Moose->init_meta(%options);
+# ABSTRACT: Make your attribute(s) tolerant to undef initialization
- return Moose::Util::MetaRole::apply_metaclass_roles(
- for_class => $options{for_class},
- attribute_metaclass_roles => [ 'MooseX::UndefTolerant::Attribute' ]
- );
-}
+__END__
-1;
+=head1 SYNOPSIS
-__END__
+ package My::Class;
-=head1 NAME
+ use Moose;
+ use MooseX::UndefTolerant;
-MooseX::Attribute::UndefTolerant - The great new MooseX::Attribute::UndefTolerant!
+ has 'name' => (
+ is => 'ro',
+ isa => 'Str',
+ predicate => 'has_name'
+ );
-=head1 SYNOPSIS
+ # Meanwhile, under the city...
+
+ # Doesn't explode
+ my $class = My::Class->new(name => undef);
+ $class->has_name # False!
+
+Or, if you only want one attribute to have this behaviour:
+
+ package My:Class;
+ use Moose;
+
+ use MooseX::UndefTolerant::Attribute;
+
+ has 'bar' => (
+ traits => [ qw(MooseX::UndefTolerant::Attribute)],
+ is => 'ro',
+ isa => 'Num',
+ predicate => 'has_bar'
+ );
+
+=head1 DESCRIPTION
+
+Loading this module in your L<Moose> class makes initialization of your
+attributes tolerant of undef. If you specify the value of undef to any of
+the attributes they will not be initialized, effectively behaving as if you
+had not provided a value at all.
+
+You can also apply the 'UndefTolerant' trait to individual attributes. See
+L<MooseX::UndefTolerant::Attribute> for details.
- use MooseX::Attribute::UndefTolerant;
+There will be no change in behaviour to any attribute with a type constraint
+that accepts undef values (for example C<Maybe> types), as it is presumed that
+since the type is already "undef tolerant", there is no need to avoid
+initializing the attribute value with C<undef>.
+As of Moose 1.9900, this module can also be used in a role, in which case all
+of that role's attributes will be undef-tolerant.
-=head1 AUTHOR
+=head1 MOTIVATION
-Cory G Watson, C<< <gphat at cpan.org> >>
+I often found myself in this quandry:
+
+ package My:Class;
+ use Moose;
+
+ has 'foo' => (
+ is => 'ro',
+ isa => 'Str',
+ );
+
+ # ... then
+
+ my $foo = ... # get the param from something
+
+ my $class = My:Class->new(foo => $foo, bar => 123);
+
+What if foo is undefined? I didn't want to change my attribute to be
+Maybe[Str] and I still want my predicate (C<has_foo>) to work. The only
+real solution was:
+
+ if(defined($foo)) {
+ $class = My:Class->new(foo => $foo, bar => 123);
+ } else {
+ $class = My:Class->new(bar => 123);
+ }
+
+Or some type of codemulch using ternary conditionals. This module allows you
+to make your attributes more tolerant of undef so that you can keep the first
+example: have your cake and eat it too!
+
+=head1 PER ATTRIBUTE
+
+See L<MooseX::UndefTolerant::Attribute>.
+
+=head1 CAVEATS
+
+This extension does not currently work in immutable classes when applying the
+trait to some (but not all) attributes in the class. This is because the
+inlined constructor initialization code currently lives in
+L<Moose::Meta::Class>, not L<Moose::Meta::Attribute>. The good news is that
+this is expected to be changing shortly.
=head1 ACKNOWLEDGEMENTS
+Many thanks to the crew in #moose who talked me through this module:
+
Hans Dieter Pearcey (confound)
Jesse Luehrs (doy)
Mike Eldridge (diz)
-=head1 COPYRIGHT & LICENSE
-
-Copyright 2009 Cory G Watson.
-
-This program is free software; you can redistribute it and/or modify it
-under the terms of either: the GNU General Public License as published
-by the Free Software Foundation; or the Artistic License.
-
-See http://dev.perl.org/licenses/ for more information.
-
-
=cut
projects / gitmo/MooseX-UndefTolerant.git / blobdiff