NAME

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

VERSION

version 0.53

SYNOPSIS

    {   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;

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 "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

SUPPORT

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>.

AUTHORS

Chris Prather <chris.prather@iinteractive.com>
Stevan Little <stevan.little@iinteractive.com>
יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>

COPYRIGHT AND LICENSE

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