MooseX::Storage::Engine::Trait::OnlyWhenBuilt - An engine trait to bypass serialization

       •   Chris Prather <chris.prather@iinteractive.com>

       •   Stevan Little <stevan.little@iinteractive.com>

       •   יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>

       This software is copyright (c) 2007 by Infinity Interactive, Inc.

       This  is  free  software;  you  can  redistribute  it and/or modify it under the same terms as the Perl 5
       programming language system itself.

perl v5.36.0                                       2022-10-16              MooseX::Storag...::OnlyWhenBuilt(3pm)

       Sometimes you don't want a particular attribute to be part of the serialization if it has not been built
       yet. If you invoke "Storage()" as outlined in the "Synopsis", only attributes that have been built (i.e.,
       where the predicate returns 'true') will be serialized.  This avoids any potentially expensive
       computations.

       This trait is applied to an instance of MooseX::Storage::Engine, for the user-visible version shown in
       the SYNOPSIS, see MooseX::Storage::Traits::OnlyWhenBuilt

       MooseX::Storage::Engine::Trait::OnlyWhenBuilt - An engine trait to bypass serialization

       Bugs may be submitted through the RT bug tracker
       <https://rt.cpan.org/Public/Dist/Display.html?Name=MooseX-Storage> (or bug-MooseX-Storage@rt.cpan.org
       <mailto:bug-MooseX-Storage@rt.cpan.org>).

       There is also a mailing list available for users of this distribution, at
       <http://lists.perl.org/list/moose.html>.

       There is also an irc channel available for users of this distribution, at "#moose" on "irc.perl.org"
       <irc://irc.perl.org/#moose>.

           {   package Point;
               use Moose;
               use MooseX::Storage;

               with Storage( traits => [qw|OnlyWhenBuilt|] );

               has 'x' => (is => 'rw', lazy_build => 1 );
               has 'y' => (is => 'rw', predicate => '_has_y' );
               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;

       version 0.53