Class::Data::Inheritable is for creating accessor/mutators to class
data.  That is, if you want to store something about your class as a
whole (instead of about a single object).  This data is then inherited
by your subclasses and can be overriden.

For example:

 Pere::Ubu->mk_classdata('Suitcase');

will generate the method Suitcase() in the class Pere::Ubu.

This new method can be used to get and set a piece of class data.

 Pere::Ubu->Suitcase('Red');
 $suitcase = Pere::Ubu->Suitcase;

The interesting part happens when a class inherits from Pere::Ubu:

 package Raygun;
 use base qw(Pere::Ubu);

 
 $suitcase = Raygun->Suitcase;

Raygun inherits its Suitcase class data from Pere::Ubu.

Inheritance of class data works analgous to method inheritance.  As
long as Raygun does not "override" its inherited class data (by using
Suitcase() to set a new value) it will continue to use whatever is set
in Pere::Ubu and inherit further changes:

 
 Pere::Ubu->Suitcase('Blue');

However, should Raygun decide to set its own Suitcase() it has now
"overridden" Pere::Ubu and is on its own, just like if it had
overriden a method:

 
 Raygun->Suitcase('Orange');

Now that Raygun has overridden Pere::Ubu futher changes by Pere::Ubu
no longer effect Raygun.

 
 Pere::Ubu->Suitcase('Samsonite');

• Vitaly Lipatov

• perl-Class-Data-Inheritable