Kevin Altis: Web Services

Thu, 06 Feb 2003 20:43:15 GMT

Shipping the prototype by Jon Udell at InfoWorld says "Let's promote scripting languages to the status they deserve"

Thu, 13 Jun 2002 20:42:18 GMT

Mark Pilgrim's article about web services in Python contains one important bit that is often overlooked by people implementing web services with XML-RPC, the listMethods extension. The Python XML-RPC ServerProxy Objects documentation explains each method: listMethods(), methodSignature(), and methodHelp().

listMethods() and its companions provide much of the same information for an XML-RPC service as WSDL does for a SOAP service; everyone that runs an XML-RPC service should provide these methods. There is no need to define any additional standards, we already have a solution. Of course, the information provided is human readable, not machine readable, so if we wanted a more machine readable form, we could define some companion methods that always output XML. WSDL is not really human readable and I haven't seen any human readable SOAP service description.

XML-RPC in Python on O'Reilly ONLamp shows how these methods are utilized by meerkat.

Thu, 13 Jun 2002 20:34:17 GMT

SOAP WSDL Verifiers and Analyzers

If you're writing client-side code and SOAP messages to talk to a web service described by a WSDL service, you'll probably benefit from seeing how one or more of the sites below parses the WSDL for a given service. If you're using a scripting language such as Python, the display of function calls and argument lists with appropriate namespace and soapaction is quite useful.

WSDL Analyzer (xmethods.net)
WSDL Validator (activestate.com)
WsdlVerify (gotdotnet.com)
WSDL Browser (gotdotnet.com)
Generic SOAP Client (soapclient.com)

This is a follow-up to my earlier post about frustrations with WSDL and SOAP interop.

Wed, 12 Jun 2002 21:29:22 GMT

XML-RPC server in PythonCard 0.6.7

A new release of PythonCard should be out in the next couple of days. You can download it from cvs now if you don't want to wait. Among the many new samples is a GUI front-end to the web server that comes with the Python Standard Libraries. In addition to serving files, the webserver sample can do CGI, so it is a great way to get a web server up quickly on your desktop; all you have to do is double-click the script. Several example CGI scripts are included with the server.

I added Mark Pilgrim's PyWebServices scripts, so the webserver can act as an XML-RPC server too. After starting up the webserver sample you can test the XML-RPC server capabilities by running the radioclient sample, which automatically shows the shell and imports the xmlrpclib module. Then try this in the shell:

>>> server = xmlrpclib.Server('http://localhost/cgi-bin/webservices.py')
>>> server.system.listMethods()
{'sample.helloWorld()': 'None', 'examples.getStateName(stateIndex)': 'None', 
'system.listMethods()': 'None'}
>>> server.sample.helloWorld()
'Hello World!'
>>> server.examples.getStateName(1)
'Alabama'
>>> server.examples.getStateName(50)
'Wyoming'