marctc / python-easy-xmlrpc

A pythonic XML-RPC microframework inspired in Django.

python-easy-xmlrpc

A pythonic XML-RPC microframework inspired in Django to build clean and well structured XML-RPC APIs.

Motivation

First of all if you need make a web API you probably should use REST instead of XML-RPC. However if you still want to use XML-RPC take a look to this package.

Python has xmlrpc module in the standard library to work with XML-RPC protocol. However it has some caveats when working with nested procedure calls. Let's take the example from the original documentation to define a XMLRPC method called currentTime.getCurrentTime():

class ExampleService:
    class currentTime:
        @staticmethod
        def getCurrentTime():
            return datetime.datetime.now()    
server.register_instance(ExampleService(), allow_dotted_names=True)

This way of define methods has some problems:

• Class names are not defined in CamelCase and function names are not defined with snake_case which means that your code won't fit the PEP8 standards.
• Unnecessary class nesting.
• Use of allow_dotted_names which is considered harmful by the own documentation:

Warning: Enabling the allow_dotted_names option allows intruders to access your module’s global variables and may allow intruders to execute arbitrary code on your machine. Only use this example only within a secure, closed network.

How to use

Create a services.py where you define XML-RPC methods:

from easyxmlrpc.decorators import xmlrpc_function

class StatusService(object):

    @xmlrpc_function()
    def ping():
        return 'pong'

class CurrentTimeService(object):

    @xmlrpc_function(name='getCurrentTime')
    def get_current_time():
        return datetime.datetime.now()

xmlrpc_function is a decorator which transforms functions in static methods and provide a function name that will be used when server registers XML-RPC functions. If name is not specified, it takes the own function name.

Then create a list of ServiceDefinition:

from easyxmlrpc.service_definition import ServiceDefinition
from .services import StatusService, CurrentTimeService

services = [
    ServiceDefinition('', StatusService),
    ServiceDefinition('currentTime', CurrentTimeService)
]

ServiceDefinition is a class used to define a nesting hierarchy between a service name and function names. In this example it will create currentTime.<method_name> as a base for the defined methods in CurrentTimeService.

Finally you can invoke a XMLRPC server in this way:

from easyxmlrpc.server import EasyXMLRPCServer
server = EasyXMLRPCServer(('localhost', 8000), services=services)
server.run()

And we can connect to XMLRPC server as usual:

import xmlrpc.client

server_proxy = xmlrpc.client.ServerProxy('http://localhost:8000')
server_proxy.ping()  #  return 'pong'
server_proxy.currentDate.getCurrentDate() # return current date