NAME
MooX::HandlesVia - NativeTrait-like behavior for Moo.
VERSION
version 0.001004
SYNOPSIS
{
package Hashy;
use Moo;
use MooX::HandleVia;
has hash => (
is => 'rw',
handles_via => 'Hash',
handles => {
get_val => 'get',
set_val => 'set',
all_keys => 'keys'
}
);
}
my $h = Hashy->new(hash => { a => 1, b => 2});
$h->get('b'); # 2
$h->set('a', 'BAR'); # sets a to BAR
my @keys = $h->all_keys; # returns a, b
DESCRIPTION
MooX::HandlesVia is an extension of Moo's 'handles' attribute
functionality. It provides a means of proxying functionality from an
external class to the given atttribute. This is most commonly used as a
way to emulate 'Native Trait' behavior that has become commonplace in
Moose code, for which there was no Moo alternative.
SHORTCOMINGS
Due to current Moo implementation details there are some deficiencies in
how MooX::HandlesVia in comparison to what you would expect from Moose
native traits.
* methods delegated via the Moo 'handles' interface are passed the
attribue value directly. and there is no way to access the parent
class. This means if an attribute is updated any triggers or type
coercions WILL NOT fire.
* Moo attribute method delegations are passed the attribute value.
This is fine for references (objects, arrays, hashrefs..) it means
simple scalar types are READ ONLY. This unfortunately means Number,
String, Counter, Bool cannot modify the attributes value, rendering
them largely useless.
PROVIDED INTERFACE/FUNCTIONS
process_has(@_)
MooX::HandlesVia preprocesses arguments passed to has() attribute
declarations via the process_has function. In a given Moo class, If
'handles_via' is set to a ClassName string, and 'handles' is set
with a hashref mapping of desired moo class methods that should map
to ClassName methods, process_has() will create the appropriate
binding to create the mapping IF ClassName provides that named
method.
has options => (
is => 'rw',
handles_via => 'Array',
handles => {
mixup => 'shuffle',
unique_options => 'uniq',
all_options => 'elements'
}
);
The following handles_via keywords are reserved as shorthand for mapping
to Data::Perl:
* Hash maps to Data::Perl::Collection::Hash::MooseLike
* Array maps to Data::Perl::Collection::Array::MooseLike
* String maps to Data::Perl::String::MooseLike
* Number maps to Data::Perl::Number::MooseLike
* Bool maps to Data::Perl::Bool::MooseLike
* Code maps to Data::Perl::Code
SEE ALSO
* Moo
* MooX::late
AUTHOR
Matthew Phillips <mattp@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2013 by Matthew Phillips
<mattp@cpan.org>.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.