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:
load_def new
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'; __PACKAGE__->load_def; 1; __DATA__ <DocumentDefinition> <name>Example_Frobulator</name> <class><module>Example::Frobulator</module></class> <element><name>frobuvalue</name></element> </DocumentDefinition>
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.
To install XML::Comma, copy and paste the appropriate command in to your terminal.
cpanm
cpanm XML::Comma
CPAN shell
perl -MCPAN -e shell install XML::Comma
For more information on module installation, please visit the detailed CPAN module installation guide.