Re: Adding traits at runtime

Yes, that works.  I guess if $params already contains some traits, I will
have to add 'My::Trait' to the list.  It's a few more lines of code, but
that's no big deal.

Thanks again,
Dan

On Mon, Jun 9, 2008 at 4:13 PM, Stevan Little <
[email protected]> wrote:

>
> On Jun 9, 2008, at 4:40 PM, Dan Harbin wrote:
>
>  Stevan,
>>
>> Thanks for the help.  I am getting the following exception:
>>
>> Can't locate object method "excludes_role" via package "Class::MOP::Class"
>> at lib/Moose/Meta/Role/Application/ToClass.pm line 25.
>>
>> I'm building a class from a YAML spec, and I want to add a trait to every
>> attribute I pull from the YAML file:
>>
>> use YAML;
>> use Moose;
>> use My::Super;
>> use My::Trait;
>>
>> my $file = shift @ARGV;
>> my $yaml = YAML::LoadFile($file);
>>
>> my $rowclass = Moose::Meta::Class->create(
>>    "My::Class",
>>    superclasses => ['My::Super'],
>> );
>>
>> my %columns = @{ $yaml->{columns} };
>> while (my ($name, $params) = each %columns) {
>>  my $attr = Moose::Meta::Attribute->new($name, %$params);
>>  My::Trait->meta->apply($attr);
>>  $rowclass->add_attribute($attr);
>> }
>>
>> Am I doing something wrong?
>>
>
> No, sorry I gave bad advice, the metaclass of the Moose::Meta::Attribute
> instance is a Class::MOP::Class an therefore does not know know about roles.
>
> Why not do:
>
>    $rowclass->add_attribute($name, %$params, traits => [ 'My::Trait' ]);
>
> This should work as expected.
>
> - Stevan
>
>
>
>
>
>
>
>>
>> On Mon, Jun 9, 2008 at 3:24 PM, Stevan Little <
>> [email protected]> wrote:
>> Dan,
>>
>> Something like this maybe?
>>
>> My::Trait->meta->apply(My::Class->meta->get_attribute('foo'));
>>
>> - Stevan
>>
>>
>> On Jun 9, 2008, at 4:21 PM, Dan Harbin wrote:
>>
>> Is there a way to add a trait to an attribute at runtime?  I know it can
>> be
>> done through the "new" method of Moose::Meta::Attribute, but what about
>> adding one after it's been initialized?
>>
>> Thanks,
>> Dan
>>
>>
>>
>