xmlrpclib and SimpleXMLRPCServer questions

[xkenneth]

So i've been trying to set up a simple server and client through
XMLRPC in python.

Here's my code:

SERVER

import SimpleXMLRPCServer


class DataServer:
def __init__(self):
pass

def test(self,test):
self.this = test

def show(self):
print self.this

server = SimpleXMLRPCServer.SimpleXMLRPCServer(("localhost", 8005))
server.register_instance(DataServer())
server.serve_forever()

CLIENT
import xmlrpclib
server = xmlrpclib.Server('http://localhost:8005')
server.test(5)
server.show()


Now, I'm getting the most odd callback from the client side:
Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1096, in __call__
return self.__send(self.__name, args)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1383, in __request
verbose=self.__verbose
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1147, in request
return self._parse_response(h.getfile(), sock)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1286, in _parse_response
return u.close()
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 744, in close
raise Fault(**self._stack[0])
xmlrpclib.Fault: <Fault 1: 'exceptions.TypeError:cannot marshal None
unless allow_none is enabled'>

What is causing this? The server recieves the data and seems to
respond properly regardless of this error, so by all means i can
always catch it, but that sounds stupid.

Here I can verify the server process is indeed recieving the data
(calling the client with two different values):

localhost - - [12/Sep/2007 14:35:18] "POST /RPC2 HTTP/1.0" 200 -
5
localhost - - [12/Sep/2007 14:35:41] "POST /RPC2 HTTP/1.0" 200 -
10

Looking at the documentation:

class SimpleXMLRPCServer( addr[, requestHandler[,
logRequests[allow_none[, encoding]]]])

I'm not sure how to specify the allow_none value or it's type, how can
i find out more?

Thanks for the help!

Regards,
Ken

 

[Jeff McNeil]

Have a look at the XMLRPC specification @ http://www.xmlrpc.com/spec.
There is no representation of NULL/None, thus server refuses to
Marshall the 'None' value. Update your server methods to return a
value other than None and that message will go away.

The other option is to set 'allow_none' to True on the Marshaller
object. Doing so will turn your 'None' return values into XML-RPC
'<nil/>' entities. The 'nil' type is defined as an XMLRPC extension
(I'm not sure how widely adopted it is, though). See
http://ontosys.com/xml-rpc/extensions.php. I'm not sure you can do
that without inheriting from the dispatcher code and "rolling your
own."

I find it much easier to 'return True' and ignore the value.

-Jeff

So i've been trying to set up a simple server and client through
XMLRPC in python.

Here's my code:

SERVER

import SimpleXMLRPCServer


class DataServer:
def __init__(self):
pass

def test(self,test):
self.this = test

def show(self):
print self.this

server = SimpleXMLRPCServer.SimpleXMLRPCServer(("localhost", 8005))
server.register_instance(DataServer())
server.serve_forever()

CLIENT
import xmlrpclib
server = xmlrpclib.Server('http://localhost:8005')
server.test(5)
server.show()


Now, I'm getting the most odd callback from the client side:
Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1096, in __call__
return self.__send(self.__name, args)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1383, in __request
verbose=self.__verbose
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1147, in request
return self._parse_response(h.getfile(), sock)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1286, in _parse_response
return u.close()
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 744, in close
raise Fault(**self._stack[0])
xmlrpclib.Fault: <Fault 1: 'exceptions.TypeError:cannot marshal None
unless allow_none is enabled'>

What is causing this? The server recieves the data and seems to
respond properly regardless of this error, so by all means i can
always catch it, but that sounds stupid.

Here I can verify the server process is indeed recieving the data
(calling the client with two different values):

localhost - - [12/Sep/2007 14:35:18] "POST /RPC2 HTTP/1.0" 200 -
5
localhost - - [12/Sep/2007 14:35:41] "POST /RPC2 HTTP/1.0" 200 -
10

Looking at the documentation:

class SimpleXMLRPCServer( addr[, requestHandler[,
logRequests[allow_none[, encoding]]]])

I'm not sure how to specify the allow_none value or it's type, how can
i find out more?

Thanks for the help!

Regards,
Ken

 

[Jeff McNeil]

Duh... you can pass allow_none=True to SimpleXMLRPCServer()....

Have a look at the XMLRPC specification @ http://www.xmlrpc.com/spec.
There is no representation of NULL/None, thus server refuses to
Marshall the 'None' value. Update your server methods to return a
value other than None and that message will go away.

The other option is to set 'allow_none' to True on the Marshaller
object. Doing so will turn your 'None' return values into XML-RPC
'<nil/>' entities. The 'nil' type is defined as an XMLRPC extension
(I'm not sure how widely adopted it is, though). See
http://ontosys.com/xml-rpc/extensions.php. I'm not sure you can do
that without inheriting from the dispatcher code and "rolling your
own."

I find it much easier to 'return True' and ignore the value.

-Jeff

So i've been trying to set up a simple server and client through
XMLRPC in python.

Here's my code:

SERVER

import SimpleXMLRPCServer


class DataServer:
def __init__(self):
pass

def test(self,test):
self.this = test

def show(self):
print self.this

server = SimpleXMLRPCServer.SimpleXMLRPCServer(("localhost", 8005))
server.register_instance(DataServer())
server.serve_forever()

CLIENT
import xmlrpclib
server = xmlrpclib.Server('http://localhost:8005')
server.test(5)
server.show()


Now, I'm getting the most odd callback from the client side:

server.show()

Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1096, in __call__
return self.__send(self.__name, args)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1383, in __request
verbose=self.__verbose
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1147, in request
return self._parse_response(h.getfile(), sock)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 1286, in _parse_response
return u.close()
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.4/
lib/python2.4/xmlrpclib.py", line 744, in close
raise Fault(**self._stack[0])
xmlrpclib.Fault: <Fault 1: 'exceptions.TypeError:cannot marshal None
unless allow_none is enabled'>

What is causing this? The server recieves the data and seems to
respond properly regardless of this error, so by all means i can
always catch it, but that sounds stupid.

Here I can verify the server process is indeed recieving the data
(calling the client with two different values):

localhost - - [12/Sep/2007 14:35:18] "POST /RPC2 HTTP/1.0" 200 -
5
localhost - - [12/Sep/2007 14:35:41] "POST /RPC2 HTTP/1.0" 200 -
10

Looking at the documentation:

class SimpleXMLRPCServer( addr[, requestHandler[,
logRequests[allow_none[, encoding]]]])

I'm not sure how to specify the allow_none value or it's type, how can
i find out more?

Thanks for the help!

Regards,
Ken