NAME
MooseX::FunkyAttributes - add code smell to your Moose attributes
SYNOPSIS
package Circle;
use Moose;
use MooseX::FunkyAttributes;
has radius => (
is => 'rw',
isa => 'Num',
predicate => 'has_radius',
);
has diameter => (
traits => [ FunkyAttribute ],
is => 'rw',
isa => 'Num',
custom_get => sub { 2 * $_->radius },
custom_set => sub { $_->radius( $_[-1] / 2 ) },
custom_has => sub { $_->has_radius },
);
DESCRIPTION
The MooseX::FunkyAttributes module itself just provides some convenience
functions for the attribute traits that are distributed with it.
The grand uniting idea behind the traits is that although Moose
generally uses blessed hashrefs for object internals, storing each
attribute as an entry in the hash, sometimes you may want to change that
behaviour for individual attributes. For example, you could use the
inside-out technique for one attribute to suppress it from appearing in
Data::Dumper dumps.
The traits bundled with MooseX::FunkyAttributes are as follows. Please
see the documentation for each individual trait for further details.
* MooseX::FunkyAttributes::Role::Attribute
Allows you to override the get, set, clear and predicate operations
for an attribute. These are just the raw operations you're
overriding; you do not need to implement type constraint checking,
coercians, checking required attributes, defaults, builders, etc.
With this trait you can create attributes which are calculated on
the fly (as in the SYNOPSIS) or stored somewhere outside the
object's blessed hashref.
* MooseX::FunkyAttributes::Role::Attribute::InsideOut
This trait stores the attribute using the inside-out technique. If
you want your whole object to be inside-out, then use
MooseX::InsideOut.
* MooseX::FunkyAttributes::Role::Attribute::Delegated
This trait delegates the storage of one attribute to another
attribute. For example:
package Head;
use Moose;
has mouth => (
is => 'ro',
isa => 'Mouth',
);
package Person;
use Moose;
use MooseX::FunkyAttributes;
has head => (
is => 'ro',
isa => 'Head',
);
has mouth => (
is => 'ro',
isa => 'Mouth::Human',
traits => [ DelegatedAttribute ],
delegated_to => 'head',
);
It is not dissimilar to the Moose's idea of "handles" (in the
example above, we could have not defined a "mouth" attribute as part
of the "Person" class, and just specified that "head" handles
"mouth") however because "mouth" is now a proper attribute in the
Person class (and will show up via Moose's introspection API), it
can have its own type constraints, coercion, trigger, predicate,
etc.
The MooseX::FunkyAttributes module itself exports some constants (e.g.
"FunkyAttribute" in the SYNOPSIS) which can be used as abbreviations for
the full trait package names. These constants are:
"FunkyAttribute"
"InsideOutAttribute"
"DelegatedAttribute"
BUGS
Please report any bugs to
<http://rt.cpan.org/Dist/Display.html?Queue=MooseX-FunkyAttributes>.
SEE ALSO
MooseX::FunkyAttributes::Role::Attribute,
MooseX::FunkyAttributes::Role::Attribute::InsideOut,
MooseX::FunkyAttributes::Role::Attribute::Delegated.
These effect storage for whole object instances; not just one attribute:
MooseX::GlobRef, MooseX::InsideOut, MooseX::ArrayRef.
MooseX::CustomInitArgs - if you have (as in the SYNOPSIS) one attribute
which is calculated from another (diameter from radius),
MooseX::CustomInitArgs will allow you to accept both attributes in the
constructor (i.e. accept a diameter in the constructor, halve it, and
set the radius attribute).
AUTHOR
Toby Inkster <tobyink@cpan.org>.
COPYRIGHT AND LICENCE
This software is copyright (c) 2012-2013 by Toby Inkster.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
DISCLAIMER OF WARRANTIES
THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.