One of the nice things about SOAP is the WDSL that gives you information
about the methods the service supports. I recently discovered that you can
do the same thing with XML-RPC. The trick is to document your methods
properly, like you should be doing anyways. Lets say I have the following
controller:
@service.xmlrpc
@service.jsonrpc
def add(num1, num2):
"""
Adds two numbers together.
add(num1, num2) -> number
Arguments:
num1 First number
num2 Second number
Returns:
The sum of the two numbers.
Examples:
add(2, 2) -> 4
add(2.5, 2.5) -> 5.0
"""
return num1 + num2
@service.xmlrpc
@service.jsonrpc
def concat(str1, str2, str3=''):
"""
Concatenates two or three strings.
concat(str1, str2, str3='') -> string
Arguments:
str1 First string
str2 Second string
str3 (Optional) Third string
Returns:
The concatenated string.
Examples:
concat('hello', ' world') -> 'hello world'
concat('hello', ' world', ' !!!') -> 'hello world !!!
"""
return str1 + str2 + str3
@service.xmlrpc
@service.jsonrpc
def date():
"""
Returns the server's current date and time.
"""
return datetime.datetime.now()
Now let's connect using xmlrpclib:
>>> import xmlrpclib
>>> x =
xmlrpclib.ServerProxy('http://127.0.0.1:8000/rpc_test/default/call/xmlrpc')
Now, we could start calling the methods as usual, or we could do a little
introspection to see what methods are available, and even get the docstrings
of those methods:
>>> print x.system.listMethods()
['add', 'concat', 'date', 'system.listMethods', 'system.methodHelp',
'system.methodSignature']
>>> print x.system.methodHelp('concat')
Concatenates two or three strings.
concat(str1, str2, str3='') -> string
Arguments:
str1 First string
str2 Second string
str3 (Optional) Third string
Returns:
The concatenated string.
Examples:
concat('hello', ' world') -> 'hello world'
concat('hello', ' world', ' !!!') -> 'hello world !!!'
>>> x.concat('hello', 'web2py')
'helloweb2py'
Very cool! However, you will notice that there is another method in there:
system.methodSignature(). This would show the signature of the method (i.e.
concat(str1, str2, str3=''), however, it seems that web2py's XMLRPC server
implementation (or SimpleXMLRPCServer.py) doesn't support this, as it
returns 'signatures not supported' whenever you try to call this method.
I hope that someone finds this useful!
