Test2::Util::ExternalMeta - Allow third party tools to safely attach meta-data to your instances.

- NAME
- DESCRIPTION
- SYNOPSIS
- WHERE IS THE DATA STORED?
- EXPORTS
- META-KEY RESTRICTIONS
- SOURCE
- MAINTAINERS
- AUTHORS
- COPYRIGHT

# NAME

Test2::Util::ExternalMeta - Allow third party tools to safely attach meta-data to your instances.

# DESCRIPTION

This package lets you define a clear, and consistent way to allow third party tools to attach meta-data to your instances. If your object consumes this package, and imports its methods, then third party meta-data has a safe place to live.

# SYNOPSIS

    package My::Object;
    use strict;
    use warnings;

    use Test2::Util::ExternalMeta qw/meta get_meta set_meta delete_meta/;

    ...

Now to use it:

    my $inst = My::Object->new;

    $inst->set_meta(foo => 'bar');
    my $val = $inst->get_meta('foo');

# WHERE IS THE DATA STORED?

This package assumes your instances are blessed hashrefs, it will not work if that is not true. It will store all meta-data in the `_meta` key on your objects hash. If your object makes use of the `_meta` key in its underlying hash, then there is a conflict and you cannot use this package.

# EXPORTS

$val = $obj->meta($key)
$val = $obj->meta($key, $default)

  This will get the value for a specified meta `$key`. Normally this will return `undef` when there is no value for the `$key`, however you can specify a `$default` value to set when no value is already set.

$val = $obj->get_meta($key)

  This will get the value for a specified meta `$key`. This does not have the `$default` overhead that `meta()` does.

$val = $obj->delete_meta($key)

  This will remove the value of a specified meta `$key`. The old `$val` will be returned.

$obj->set_meta($key, $val)

  Set the value of a specified meta `$key`.

# META-KEY RESTRICTIONS

Meta keys must be defined, and must be true when used as a boolean. Keys may not be references. You are free to stringify a reference `"$ref"` for use as a key, but this package will not stringify it for you.

# SOURCE

The source code repository for Test2 can be found at http://github.com/Test-More/test-more/.

# MAINTAINERS

Chad Granum <exodist@cpan.org>

# AUTHORS

Chad Granum <exodist@cpan.org>

# COPYRIGHT

Copyright 2020 Chad Granum <exodist@cpan.org>.

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

See http://dev.perl.org/licenses/

Test2::Util::ExternalMeta - Allow third party tools to safely attach meta-data to your instances.