MooseX::SetOnce - write-once, read-many attributes for Moose
Add the "SetOnce" trait to attributes:
package Class; use Moose; use MooseX::SetOnce; has some_attr => ( is => 'rw', traits => [ qw(SetOnce) ], );
...and then you can only set them once:
my $object = Class->new; $object->some_attr(10); # works fine $object->some_attr(20); # throws an exception: it's already set!
The 'SetOnce' attribute lets your class have attributes that are not lazy and not set, but that cannot be altered once set.
The logic is very simple: if you try to alter the value of an attribute with the SetOnce trait, either by accessor or writer, and the attribute has a value, it will throw an exception.
If the attribute has a clearer, you may clear the attribute and set it again.
Ricardo SIGNES <firstname.lastname@example.org>
This software is copyright (c) 2011 by Ricardo SIGNES.