MooseX::SetOnce - write-once, read-many attributes for Moose
Add the "SetOnce" trait to attributes:
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) 2013 by Ricardo SIGNES.
This is free software; you can redistribute it and/or modify it under the same
terms as the Perl 5 programming language system itself.