Thanks Stevan,
I'm impressed by the quick turnaround, and I look forward to trying
out the new release.
Charles Alderman
aldermania.com
----- Original Message -----
From: Stevan Little <[EMAIL PROTECTED]>
Sent: Sat, 12 Apr 2008 23:55:24 -0400
Re: Re: attribute w/ coerce and trigger - trigger arguments
Charles,
This bug has been fixed in svn
(http://code2.0beta.co.uk/moose/svn/Moose/trunk/) and will be in the
next release (coming soon, probably this week sometime).
- Stevan
On Apr 9, 2008, at 2:40 PM, Charles Alderman wrote:
Hello,
Just started using Moose (love it). I recently spent a little time
struggling through an issue with trigger arguments for a coerced
attribute. So, I thought I'd post what I found here in case anyone
else runs into it.
Actually, I'm not sure if I found an undocumented feature of Moose,
or if it's a bug. The docs say that a trigger is passed an
updated value of the attribute. What happens is that if the
attribute has a coercion, the argument passed to the trigger
hasn't been coerced. So, technically, the argument isn't an
updated value. (At least, that's where my confusion came from.)
The coerced value is still available to the trigger through the
attribute's accessor, so maybe having the non-coerced value also
available is for the best.
For clarification, I included an example.
Thanks,
Charles Alderman
aldermania.com
Versions:
Moose - 0.40
Class::MOP - 0.54
--
From the Moose perldoc:
The trigger option is a CODE reference which will be called after
the value of the attribute is set. The CODE ref will be passed the
instance itself, the **updated value** and the attribute
meta-object (this is for more advanced fiddling and can typically
be ignored).
--
Here's an example:
#This example is based on: Schwartz, R.L. "The Moose is Flying
(part 2)". LinuxMag Column 95 (Jul 2007)
package Mortgage;
use Moose;
use Moose::Util::TypeConstraints;
use DateTime;
use DateTime::Format::DateManip;
use Date::Manip;
Date_Init( 'TZ=US/Eastern' );
subtype 'DateTime'
=> as 'Object'
=> where { $_->isa('DateTime') };
coerce 'DateTime'
=> from 'Str' => via {
DateTime::Format::DateManip->parse_datetime($_) }
=> from 'HashRef' => via { DateTime->new(%$_) };
has 'closing_date' => (
is => 'rw',
isa => 'DateTime',
coerce => 1,
trigger => sub {
my ( $self, $val, $meta ) = @_;
print $self->closing_date->isa('DateTime') ? 'yes' : 'no'; # yes
print $val->isa('DateTime') ? 'yes' : 'no'; # no???
}
);
1;
package main;
my $mtg = Mortgage->new( closing_date => 'yesterday' );
print $mtg->closing_date->isa('DateTime') ? 'yes' : 'no'; # yes
