MooseX::Clone - Fine-grained cloning support for Moose objects.
package Bar;
use Moose;
with qw(MooseX::Clone);
has foo => (
isa => "Foo",
traits => [qw(Clone)], # this attribute will be recursively cloned
);
package Foo;
use Moose;
# this API is used/provided by MooseX::Clone
sub clone {
my ( $self, %params ) = @_;
# ...
}
# used like this:
my $bar = Bar->new( foo => Foo->new );
my $copy = $bar->clone( foo => [ qw(Args for Foo::clone) ] );
Out of the box Moose only provides very barebones cloning support in order to
maximize flexibility.
This role provides a "clone"
method that makes use of the low level cloning support already in Moose and
adds selective deep cloning based on introspection on top of that.
Attributes with the "Clone" trait will
handle cloning of data within the object, typically delegating to the
attribute value's own "clone" method.
- Clone
- By default Moose objects are cloned like this:
bless { %$old }, ref $old;
By specifying the Clone trait for certain attributes custom
behavior the value's own "clone"
method will be invoked.
By extending this trait you can create custom cloning for
certain attributes.
By creating "clone" methods
for your objects (e.g. by composing MooseX::Compile) you can make them
interact with this trait.
- NoClone
- Specifies attributes that should be skipped entirely while cloning.
- clone %params
- Returns a clone of the object.
All attributes which do the
MooseX::Clone::Meta::Attribute::Trait::Clone role will handle cloning of
that attribute. All other fields are plainly copied over, just like in
"clone_object" in Class::MOP::Class.
Attributes whose "init_arg"
is in %params and who do the
"Clone" trait will get that argument
passed to the "clone" method
(dereferenced). If the attribute does not self-clone then the param is
used normally by "clone_object" in Class::MOP::Class, that is
it will simply shadow the previous value, and does not have to be an
array or hash reference.
Refactor to work in term of a metaclass trait so that
"meta->clone_object" will still do the
right thing.
clkao made the food required to write this module
XXXX XXX'XX (Yuval Kogman) <nothingmuch@woobling.org>
This software is copyright (c) 2008 by XXXX XXX'XX (Yuval Kogman).
This is free software; you can redistribute it and/or modify it
under the same terms as the Perl 5 programming language system itself.