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) 2012-2014 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.