note happy.barney few notes:<br> use dispatch map <code> our $dispatch_map = { xml => 'My::XML', json => 'My::JSON', }; sub new { ... die unless exists $dispatch_map->{$args{source}}; my $class = $dispatch_map->{$args{source}} Module::Load::load ($class); $self->{engine} = $class; # or $class->new ($self); } </code> you can call foreign methods ... <code> $self->My::JSON::_init; # or my $method = $self->{engine} . '::_init'; $self->$method; </code> 867690 867690