---
name: "MooseX::Storage::Traits::OnlyWhenBuilt"
section: "3pm"
platform: "linux"
package: "libmoosex-storage-perl"
version: "0.53-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/MooseX::Storage::Traits::OnlyWhenBuilt"
---

# MooseX::Storage::Traits::OnlyWhenBuilt(3pm)

A custom trait to bypass serialization

## NAME

MooseX::Storage::Traits::OnlyWhenBuilt - A custom 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.

See the SYNOPSIS for a nice example that can be easily cargo-culted.

## 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 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.