Sinister has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

I am fidling around with RPC::XML (an xml-rpc implementation for Perl) - which seemed the most usable of xml-rpc/soap thingies out there in the perl world.

However; it is not really working...

I have a test server and client doing a simple 'system.listMethods' - but the result is empty. Now I know the documentation says:

"If the return value from send_request is not a reference, then it can only mean an error on the client-side (a local problem with the arguments and/or syntax, or a transport problem)."

But I don't realy see what's wrong with this code: 
#!/opt/perl/bin/perl -Tl

use warnings;
use strict;

use RPC::XML::Client;

my $client = RPC::XML::Client->new('http://localhost:8000/');
my $result = $client->send_request('system.listMethods');
die $result unless defined($result);
die $result;
die $result->code . ': ' . $result->string if $result->is_fault;
print join(' ',  @{$result->value}), "\n";

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This gracefully dies with: Died at ./client.pl line 11.

What's more; using tcpflow (i know - evil) i can see a succesfull POST including a good return containing valid XML. (tried to validate it with XML::Parser, which works like a charm)

So a transport problem doesn't seem to be the problem either.

Any suggestions on how I can (tackle || find the root of) this problem?


er formait hyarya.
-- "Life is a house and the next tornado is never far away"
-- "lovely by nature"

Replies are listed 'Best First'.
Re: RPC::XML::Client question
by mirod (Canon) on Jan 06, 2004 at 15:45 UTC
    I am fidling around with RPC::XML (an xml-rpc implementation for Perl) - which seemed the most usable of xml-rpc/soap thingies out there in the perl world.

    Are you sure XML::RPC is easier to use than SOAP::Lite? I have little practical experience in the domain, but it looks like SOAP::Lite is quite easy to use, and soaplite.com has quite a bit of documentation, including a cookbook.

    For both SOAP::Lite and XML::RPC you could read Programming Web Services with Perl, and have a look at the companion website.

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Re: RPC::XML::Client question
by Roger (Parson) on Jan 06, 2004 at 13:32 UTC
    You could use the Data::Dumper module to inspect the returned $result structure.
    use Data::Dumper;

...
my $result = $client->send_request...;
print Dumper($result);

    [download]
[reply]
[d/l]
      But that's just the problem. $result = ''; It is defined, but still very much so empty... It's not even a reference :-(


      er formait hyarya.
      -- "Life is a house and the next tornado is never far away"
      -- "lovely by nature"
[reply]
[d/l]
        Did you check if the $client is built properly? You could add another print Dumper($client);. I just think the line my $client = RPC::XML::Client->new('http://localhost:8000/'); looks doggy, don't you need to specify the name of the service in the URL? Something like 'http://localhost:8000/cgi-bin/rpcserver'.

        And you could also invoke the perl debugger and step into the send_request method, and see step by step what is happenning inside the module. Are you on Linux? If so, you could just invoke the ddd visual debugger by specifying -perl on the commandline, together with the name of your script.

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[d/l]
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Re: RPC::XML::Client question
by Sinister (Friar) on Jan 06, 2004 at 16:01 UTC
    Hhmzz ... i found my problem the '-l' switch was in the shebang of the server.

    *hangs head in shame*



    er formait hyarya.
    -- "Life is a house and the next tornado is never far away"
    -- "lovely by nature"
[reply]
[d/l]

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