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MooseX-SetOnce-0.100471
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/ MooseX::SetOnce

NAME

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

VERSION

version 0.100471

SYNOPSIS

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!

DESCRIPTION

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.

AUTHOR

Ricardo SIGNES <rjbs@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2010 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.