On Mon, Feb 16, 2009 at 1:09 PM, Chad Davis <[email protected]> wrote:
> Is someone still following that might also have a good solution for
> preventing unwanted values from getting into an attribute?
Well my first thought was you wanted an initializer but looking at my
own notes for an outstanding doc patch I promised they don't get fired
on setting an attribute just on creating an attribute.
So I then remembered that you could pass something other than a string
to writer and I though possibly that was a subref, in the Class::MOP
documentation it says:
The accessor, reader, writer, predicate and clearer keys can
contain either; the name of the method and an appropriate default one
will be generated for you, or a
HASH ref containing exactly one key (which will be used as the
name of the method) and one value, which should contain a CODE
reference which will be
installed as the method itself.
which says that you can write:
has myattr => (
isa => 'Str',
accessor => {
myattr => sub {
my ( $self, $value ) = @_;
if ( defined $value ) { ( $self->{myattr} = $value ) =~ s/\s//g }
return $self->{myattr};
},
},
);
to get to where you want to be. I can think that a patch to
Class::MOP::Attribute to allow CODE refs as well as HASH refs might
make this situation cleaner ... but this should work in the current
code. Here's an example that I tested:
package Class;
use Moose;
has foo => (
accessor => {
foo => sub { my ( $s, $v ) = @_; $s->{foo} = $v + 1 }
}
);
my $o = Class->new;
$o->foo(1);
say $o->dump
