How to Persist SOAP Headers in SOAP::Lite

I discovered recently that SOAP::Lite isn't necessary well-behaved when it comes to conforming to SOAP intermediary requirements. According to the spec, SOAP services must ignore headers not addressed to them and must pass them along untouched in any response they deliver. Now most developers don't need to worry about this because this capability is only relevant to people invoking SOAP intermediaries. However, at Grand Central where I work, we use SOAP intermediaries all the time; in one scenario, we were calling a Web Service I built using Perl, but it did not persist SOAP Headers properly. So, I wrote some code to address the problem, and now it works as the SOAP spec requires.

Here is an excerpt from a Perl Module that SOAP Messages are dispatched to. What you see in the code below is a loop that grabs the SOAP Headers found in a request, and iteratively adds them as SOAP Headers in a response.

The dataof method returns a SOAP::Data object, which of course is problematic in that if we were to add a SOAP::Data element to the response, it would be serialized into the message's Body. Therefore, we bless the object as a SOAP::Header, and presto - it now is serialized properly into the messages Header block.

sub getCatalog {
    my $self = shift;
    my $envelope = pop;
    my $req_hdr = $envelope->match(SOAP::SOM::header)->dataof;
    my @res_hdrs;
    foreach my $h ( $req_hdr->value ) {
        foreach my $name (keys %$h) {
            push( @res_hdrs, bless $envelope->match(SOAP::SOM::header."/$name")->dataof, "SOAP::Header" );
        }
    }
    return @res_hdrs, SOAP::Data->name('foo' => 'bar');
}