Dear wisest PerlMonks!

I have a problem concerning Moose traits: When defining a class role and requiring some method with requires, the method has to be implemented in the class.

But where/how to implement a method that is required by an attribute trait?

UPDATE: Alternatively, is it possible to use MooseX::Role::Parameterized together with attribute traits?

Example: 

use MooseX::Declare;
role My::DirOption {
    requires '_build_rootdir';
    
    has rootdir => (
        isa => 'Str',
        is => 'rw',
        lazy => 1,
        builder => '_build_rootdir',
    );
}
# Make meta attribute trait known to Moose under a short name 
class Moose::Meta::Attribute::Custom::Trait::DirOption {
    sub register_implementation {'My::DirOption'}
}

class My::Config {
    use strict;
    use warnings;

    has testdir => (
        traits => ['DirOption'],
        isa => 'Str',
        is => 'rw',
    );

    ## This is the wrong place for the builder!
    method _build_rootdir() {
        return '/home/paulatreides';
    }
}
1;

[download]
This gives: 
'My::DirOption' requires the method '_build_rootdir' to be implemented
+ by 'Class::MOP::Class::__ANON__::SERIAL::9'

[download]

Is there anybody who can light my darkness?

In reply to Moose: Where to define a method required by an attribute trait? by maxhq

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