Re^2: NonMoose and (clean) inheritance

[eco]

Thanks for your answer! My preferred declaration of ClassB is as follows:

package ClassB;
use Moose;
extends 'ClassA';

has '+param1' => (default => 'PARAM1-CLASSB');
has '+param2' => (default => 'PARAM2-CLASSB');

But since this doesn't work for the param1, I figured to use FOREIGNBUILDARGS and BUILDARGS to have some similarity in usage. Your builders solution seems to do this better though. So thank you very much for the idea!

But if I could change ClassA to allow above syntax for ClassB that would be awesome

[tobyink]

Builders are just generally a better idea than defaults. (MooseX::Manual::BestPractices even tells you so.) They give you a nice clean way to override the behaviour in subclasses.

If you use Moo or MooseX::AttributeShortcuts then you can even do:

has foo => (is => 'ro', builder => sub { ... });

... and it will automatically get "translated" to:

has foo => (is => 'ro', builder => '_build_foo');
sub _build_foo { ... }

... so builders can be just as convenient as defaults are.

[eco]

Thanks for the link of Moose best practices. I didn't know about that one! It's true that builders are preferred over defaults, but it also specifies "However, do use a default when the default is a non-reference.." which happens to be the case here. But hence, for now your solution with builders is the best I have...