MooseX::SetOnce(3) write-once, read-many attributes for Moose


version 0.200002


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 <[email protected]>


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.