* add support for Storage( traits => [...] ) to alter the behaviour of the

[gitmo/MooseX-Storage.git] / lib / MooseX / Storage / Traits / OnlyWhenBuilt.pm

diff --git a/lib/MooseX/Storage/Traits/OnlyWhenBuilt.pm b/lib/MooseX/Storage/Traits/OnlyWhenBuilt.pm
new file mode 100644 (file)
index 0000000..a3b9752
--- /dev/null
+++ b/lib/MooseX/Storage/Traits/OnlyWhenBuilt.pm
@@ -0,0 +1,82 @@
+package MooseX::Storage::Traits::OnlyWhenBuilt;
+use Moose::Role;
+
+our $VERSION   = '0.18';
+our $AUTHORITY = 'cpan:STEVAN';
+
+1;
+
+__END__
+
+=pod
+
+=head1 NAME
+
+MooseX::Storage::Traits::OnlyWhenBuilt - A custom trait to bypass serialization
+
+=head1 SYNOPSIS
+
+
+    {   package Point;
+        use Moose;
+        use MooseX::Storage;
+    
+        with Storage( traits => [qw|OnlyWhenBuilt|] );
+    
+        has 'x' => (is => 'rw', lazy_build => 1 );
+        has 'y' => (is => 'rw', lazy_build => 1 );
+        has 'z' => (is => 'rw', builder => '_build_z' );
+        
+        
+        sub _build_x { 3 }
+        sub _build_y { expensive_computation() }
+        sub _build_z { 3 }
+    
+    }
+    
+    my $p = Point->new( 'x' => 4 );
+ 
+    # the result of ->pack will contain:
+    # { x => 4, z => 3 }
+    $p->pack;
+ 
+=head1 DESCRIPTION
+
+Sometimes you don't want a particular attribute to be part of the 
+serialization if it has not been built yet. If you invoke C<Storage()>
+as outlined in the C<Synopsis>, only attributes that have been built
+(ie, where the predicate returns 'true') will be serialized.
+This avoids any potentially expensive computations.
+
+See the SYNOPSIS for a nice example that can be easily cargo-culted.
+
+=head1 METHODS
+
+=head2 Introspection
+
+=over 4
+
+=item B<meta>
+
+=back
+
+=head1 BUGS
+
+All complex software has bugs lurking in it, and this module is no 
+exception. If you find a bug please either email me, or add the bug
+to cpan-RT.
+
+=head1 AUTHOR
+
+Stevan Little E<lt>stevan.little@iinteractive.comE<gt>
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright 2007-2008 by Infinity Interactive, Inc.
+
+L<http://www.iinteractive.com>
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
+
+=cut