doc bug

[Evan Carroll]

In the docs I see this for Moose::Meta::Attribute


## EXCERPT
get_value
set_value

  eval { $point-meta-get_attribute('x')-set_value($point, 'forty-two') };
  if($@) {
print Oops: $...@\n;
  }

Attribute (x) does not pass the type constraint (Int) with 'forty-two'

Before setting the value, a check is made on the type constraint
of the attribute, if it has one, to see if the value passes it. If the
value fails to pass, the set operation dies with a throw_error.

Any coercion to convert values is done before checking the type constraint.

To check a value against a type constraint before setting it,
fetch the attribute instance using find_attribute_by_name in
Class::MOP::Class, fetch the type_constraint from the attribute using
type_constraint in Moose::Meta::Attribute and call check in
Moose::Meta::TypeConstraint. See Moose::Cookbook::Basics::Recipe4 for
an example.

## END

But, yet get_value doesn't seem to be working.

perl -Moose -e'has q[format_feed]= ( isa = Str, is = ro );
print Class-new-meta-get_attribute(q[format_feed])-get_value()'

You must pass a package name and it cannot be blessed at
/usr/local/lib/perl/5.10.0/Class/MOP/Class.pm line 37
Class::MOP::Class::initialize('Class::MOP::Class', '') called at
/usr/local/lib/perl/5.10.0/Class/MOP/Attribute.pm line 322

Class::MOP::Attribute::get_raw_value('Moose::Meta::Attribute=HASH(0x91c8310)',
undef) called at /usr/local/lib/perl/5.10.0/Class/MOP/Attribute.pm
line 309

Class::MOP::Attribute::get_value('Moose::Meta::Attribute=HASH(0x91c8310)',
undef) called at /usr/local/share/perl/5.10.0/Moose/Meta/Attribute.pm
line 562

Moose::Meta::Attribute::get_value('Moose::Meta::Attribute=HASH(0x91c8310)')
called at -e line 3

I guess it is using Class::MOP::Attribute's get_value which requires a
class name. This is odd, I just want to read from the sucker, in the
source of Mooose::Meta::Attribute I see this return
$self-SUPER::get_value($instance) which seems to imply the instance
is being set, but it isn't working. Any ideas?

-- 
Evan Carroll
System Lord of the Internets
http://www.evancarroll.com

Re: doc bug

[Jesse Luehrs]

On Tue, Nov 03, 2009 at 05:21:12PM -0600, Evan Carroll wrote:
 perl -Moose -e'has q[format_feed]= ( isa = Str, is = ro );
 print Class-new-meta-get_attribute(q[format_feed])-get_value()'

get_value and set_value both require the instance as the first argument,
as pointed out in the docs for Class::MOP::Attribute. The attribute
object doesn't have a value itself, since it's part of the class... you
have to tell it which instance you want to get the value from.

my $obj = Class-new;
$obj-meta-get_attribute('foo')-get_value($obj);

-doy