XML::Comma::Util::DefModule - Abstract parent for modules that define a Def in a __DATA__ block.


This module provides an easy way to define a Def inside a module. Children of XML::Comma::Util::DefModule inherit two methods:


The Def is created from a string found in the DATA section of the module. The load_def() method should be called by the inheriting class, in order to load the Def into Comma's weltenshmatzel. The default new() method simply returns a new Doc of the Def's type, and can be used as-is or overridden. A complete, basic inheritor might look like this:

  package Example::Frobulator;

  use strict;
  use warnings;

  use base 'XML::Comma::Util::DefModule';





You can access the def from this object in a variety of ways, all of which are equivalent:

  $def = XML::Comma::Def->Example_Frobulator;
  $def = Example::Frobulator->load_def();
  $def = Example::Frobulator->def();
  $def = Example::Frobulator->new(%args)->def();

NOTE: when overriding def(), it is easy to make a circular reference which cannot be garbage collected, leading to various unintuitive problems. NEVER DO THIS:

  sub def {
    my $def = XML::Comma::Def->read( name => "Example_Frobulator" );
    #do some stuff with $def
    return $def;

The safe way to do this is to use DefModule's def() method, which has magic to take care of proper memory management for you:

  sub def {
    my $def = __PACKAGE__->def;
    #do some stuff with $def
    return $def;

As an added bonus, def() implemented this way will work when called from a class or instance, like the default.