Re: Trying to create an attribute trait that prompts for a value if none specified

Todd,

> Not quite... We're not changing the default metaclass for everything, but
> rather applying a metarole to the metaclass of the consuming class. (I think
> that's how it goes -- I'm still not sure of the correct terminology.)

Yes, true, but my thinking goes (and I freely admit I could be wrong
on the details) that, by applying a metarole to the metaclass, that
generates an anonymous class which composes the role.  So it is, in
effect, a new metaclass, not technically for everything, but for
everything from that point forward (till end of file or end of scope).

> (If you're
> concerned about prompting during cloning and/or reblessing, there'll be a
> little more work to do.)

Perhaps, although at that point there would be a value from the
original instantiation, so as long as I only prompt when there's no
value, I should be good.

> Don't know if it's a good approach by Moose Cabal
> standards, but it's direct.

True. :-)  LIS, I'm just wondering what people think about the two
approaches: creating an attribute trait vs applying a metarole to the
metaclass.  Is one better than the other in certain respects?  Is one
academically/philosophically better (an interesting point, although
mostly moot)?  What about practical aspects?  Does one work in
scenario X where the other doesn't?  That sort of thing.


Back to ealleniii's solution, I managed to track down the
add_attribute() method of the metaclass (it's in
Class::MOP::Mixin::HasAttributes; not sure why I couldn't find that on
CPAN) and I see it is indeed smart enough to remove the old attribute
of the same name before adding the new one.  I'm still a little fuzzy
on whether the memory would get freed, but I'm assuming so.  So I'm
going to play around with this one a bit more.


            -- Buddy