http://www.perlmonks.org?node_id=1018035


in reply to Dear Moose docs...

You're right that the docs are a little sparse in that area. There are some examples though - Moose::Manual::Attributes, Moose::Cookbook::Basics::Point_AttributesAndSubclassing, Moose::Cookbook::Basics::BankAccount_MethodModifiersAndSubclassing, etc. If you don't think this is enough, please submit a bug report.

Out of the box, Moose supports two styles of object construction:

# Key-value pairs my $point1 = Point->new(x => 10, y => 20); # Hashref my $point2 = Point->new({ x => 10, y => 20 });

In your class it's possible to override BUILDARGS to add your own argument parsing...

use v5.12; { package Point; use Moose; has 'x' => (is => 'rw', isa => 'Int'); has 'y' => (is => 'rw', isa => 'Int'); around BUILDARGS => sub { my $orig = shift; my $self = shift; # Allow object to be built by passing two integers... if (@_ == 2 and $_[0] =~ /^[0-9]+$/ and $_[1] =~ /^[0-9]+$/) { return { x => $_[0], y => $_[1] }; } # If not two integers, then fall back to standard Moose BUILDA +RGS... return $self->$orig(@_); }; __PACKAGE__->meta->make_immutable; } # Use our overridden BUILDARGS... print Point->new(10, 20)->dump; # Standard Moose BUILDARGS is fallback... print Point->new(x => 10, y => 20)->dump; print Point->new({ x => 10, y => 20 })->dump;
package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name