soap.py   [plain text]

# -*- test-case-name: twisted.test.test_soap -*-
# Twisted, the Framework of Your Internet
# Copyright (C) 2001 Matthew W. Lefkowitz
# 
# This library is free software; you can redistribute it and/or
# modify it under the terms of version 2.1 of the GNU Lesser General Public
# License as published by the Free Software Foundation.
# 
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
# 
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""SOAP support for twisted.web.

Requires SOAPpy 0.10.1 or later.

API Stability: unstable

Maintainer: U{Itamar Shtull-Trauring<mailto:twisted@itamarst.org}

Future plans:
SOAPContext support of some kind.
Pluggable method lookup policies.
"""

# SOAPpy
import SOAPpy

# twisted imports
from twisted.web import server, resource, client
from twisted.internet import defer
from twisted.python import log, failure


class SOAPPublisher(resource.Resource):
    """Publish SOAP methods.

    By default, publish methods beginning with 'soap_'. If the method
    has an attribute 'useKeywords', it well get the arguments passed
    as keyword args.
    """

    isLeaf = 1
    
    # override to change the encoding used for responses
    encoding = "UTF-8"

    def lookupFunction(self, functionName):
        """Lookup published SOAP function.

        Override in subclasses. Default behaviour - publish methods
        starting with soap_, if they have true attribute useKeywords
        they are expected to accept keywords.
        
        @return: tuple (callable, useKeywords), or (None, None) if not found.
        """
        function = getattr(self, "soap_%s" % functionName, None)
        if function:
            return function, getattr(function, "useKeywords", False)
        else:
            return None
    
    def render(self, request):
        """Handle a SOAP command."""
        data = request.content.read()

        p, header, body, attrs = SOAPpy.parseSOAPRPC(data, 1, 1, 1)

        methodName, args, kwargs, ns = p._name, p._aslist, p._asdict, p._ns

        # deal with changes in SOAPpy 0.11
        if callable(args):
            args = args()
        if callable(kwargs):
            kwargs = kwargs()

        function, useKeywords = self.lookupFunction(methodName)
        
        if not function:
            self._methodNotFound(request, methodName)
            return server.NOT_DONE_YET
        else:
            if hasattr(function, "useKeywords"):
                keywords = {}
                for k, v in kwargs.items():
                    keywords[str(k)] = v
                d = defer.maybeDeferred(function, **keywords)
            else:
                d = defer.maybeDeferred(function, *args)

        d.addCallback(self._gotResult, request, methodName)
        d.addErrback(self._gotError, request, methodName)
        return server.NOT_DONE_YET

    def _methodNotFound(self, request, methodName):
        response = SOAPpy.buildSOAP(SOAPpy.faultType("%s:Client" % SOAPpy.NS.ENV_T,
                                                 "Method %s not found" % methodName),
                                  encoding=self.encoding)
        self._sendResponse(request, response, status=500)
    
    def _gotResult(self, result, request, methodName):
        if not isinstance(result, SOAPpy.voidType):
            result = {"Result": result}
        response = SOAPpy.buildSOAP(kw={'%sResponse' % methodName: result},
                                  encoding=self.encoding)
        self._sendResponse(request, response)

    def _gotError(self, failure, request, methodName):
        e = failure.value
        if isinstance(e, SOAPpy.faultType):
            fault = e
        else:
            fault = SOAPpy.faultType("%s:Server" % SOAPpy.NS.ENV_T, "Method %s failed." % methodName)
        response = SOAPpy.buildSOAP(fault, encoding=self.encoding)
        self._sendResponse(request, response, status=500)

    def _sendResponse(self, request, response, status=200):
        request.setResponseCode(status)

        if self.encoding is not None:
            mimeType = 'text/xml; charset="%s"' % self.encoding
        else:
            mimeType = "text/xml"
        request.setHeader("Content-type", mimeType)
        request.setHeader("Content-length", str(len(response)))
        request.write(response)
        request.finish()


class Proxy:
    """A Proxy for making remote SOAP calls.

    Pass the URL of the remote SOAP server to the constructor.

    Use proxy.callRemote('foobar', 1, 2) to call remote method
    'foobar' with args 1 and 2, proxy.callRemote('foobar', x=1)
    will call foobar with named argument 'x'.
    """

    # at some point this should have encoding etc. kwargs
    def __init__(self, url, namespace=None, header=None):
        self.url = url
        self.namespace = namespace
        self.header = header

    def _cbGotResult(self, result):
        return SOAPpy.parseSOAPRPC(result).Result
        
    def callRemote(self, method, *args, **kwargs):
        payload = SOAPpy.buildSOAP(args=args, kw=kwargs, method=method,
                                   header=self.header, namespace=self.namespace)
        return client.getPage(self.url, postdata=payload, method="POST",
                              headers={'content-type': 'text/xml'}
                              ).addCallback(self._cbGotResult)