X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMooseX%2FUndefTolerant.pm;h=f5cac2b68ffbcb5a159e16e89c4bd432704eea45;hb=1686337d5495ade429b48cd5cf7fb4c2d709c362;hp=419a7b435893d8c85a83b2f9017a7483a62f3167;hpb=5447ee457d5fd503926799cb8efb8552bdb4764d;p=gitmo%2FMooseX-UndefTolerant.git

diff --git a/lib/MooseX/UndefTolerant.pm b/lib/MooseX/UndefTolerant.pm
index 419a7b4..f5cac2b 100644
--- a/lib/MooseX/UndefTolerant.pm
+++ b/lib/MooseX/UndefTolerant.pm
@@ -1,47 +1,128 @@
 package MooseX::UndefTolerant;
-use strict;
-use warnings;
 
 use Moose qw();
 use Moose::Exporter;
-use Moose::Util::MetaRole;
 
 use MooseX::UndefTolerant::Attribute;
+use MooseX::UndefTolerant::Class;
+use MooseX::UndefTolerant::Constructor;
 
-our $VERSION = '0.01';
 
-Moose::Exporter->setup_import_methods();
+my %metaroles = ( attribute => [ 'MooseX::UndefTolerant::Attribute' ] );
+if ( $Moose::VERSION < 1.9900 ) {
+        $metaroles{constructor} = [ 'MooseX::UndefTolerant::Constructor' ];
+}
+else {
+        $metaroles{class} = [ 'MooseX::UndefTolerant::Class' ];
+}
 
-sub init_meta {
-    my (undef, %options) = @_;
 
-    Moose->init_meta(%options);
-
-    return Moose::Util::MetaRole::apply_metaclass_roles(
-        for_class => $options{for_class},
-        attribute_metaclass_roles => [ 'MooseX::UndefTolerant::Attribute' ]
-    );
-}
+Moose::Exporter->setup_import_methods(
+    class_metaroles => \%metaroles,
+);
 
 1;
 
+# ABSTRACT: Make your attribute(s) tolerant to undef initialization
+
 __END__
 
-=head1 NAME
+=head1 SYNOPSIS
 
-MooseX::Attribute::UndefTolerant - The great new MooseX::Attribute::UndefTolerant!
+  package My::Class;
 
-=head1 SYNOPSIS
+  use Moose;
+  use MooseX::UndefTolerant;
+
+  has 'name' => (
+    is => 'ro',
+    isa => 'Str',
+    predicate => 'has_name'
+  );
+
+  # 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>.
 
+=head1 MOTIVATION
 
-=head1 AUTHOR
+I often found myself in this quandry:
 
-Cory G Watson, C<< <gphat at cpan.org> >>
+  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 ternarys.  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::Method::Constructor>, 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)
@@ -54,15 +135,4 @@ Jay Shirley (jshirley)
 
 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