Hi BrowserUk,

You are right in your assumptions. My::XML and My::JSON only provide data to the inherited class, no other methods are used (except methods internally used by My::XML or My::JSON).

If so, if you instantiated an instance of the relevant XML or JSON class to just parse the source data; then retrieved the data required by My class; and then allowed the parse instance to be reclaimed as soon as the initialisation of a new My class instance was complete; then your My class instances might be individually smaller. And possibly more efficien,t because of shorter method resolution paths.

Sorry if I misunderstand your. Are you suggesting the following?:

Package My:

sub new {
   my ($class,%args) = @_;

   my $data;
   if ($args{source} eq 'xml') {
      require My::XML;
      # @ISA = qw/My::XML/;
      $data = My::XML->new(%args);
   } elsif ($args{source} eq 'json') {
      require My::JSON;
      # @ISA = qw/My::JSON/;
      $data = My::JSON->new(%args);
   }

   my $self = bless \%{$data}, $class;
   return ($self);
}
# rest of methods
sub method1 { ... }
sub method2 { ... }

1;
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Package My::XML

package My::XML;

use XML::Simple qw(:strict);

sub new
{
   my ($class,%args) = @_;
   my $self = bless {}, $class;
   $self->_init();
   return $self;
}

sub _init { # Code to read the data from XML source }

1;
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Same for My::JSON

Thank you very much for your comments