Test2::Util::ExternalMeta(3pm) Perl Programmers Reference Guide Test2::Util::ExternalMeta(3pm)

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

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.

    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');

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.

$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 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.

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

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/

2022-02-19 perl v5.34.1