package MyApp::Controller::Service;
use strict;
use warnings;
use base qw(Catalyst::Controller::SOAP::DocumentLiteralWrapped);

__PACKAGE__->config->{wsdl} = 'foo.wsdl';
__PACKAGE__->config->{soap_action_prefix} = 'http://example.com/';

sub operation : SOAP('DocumentLiteral') {
   # The final operation is still DocumentLiteral, but
   # the superclass registers a dispatcher that will 
   # forward to this action based on the SOAPAction
   # header.
}