def addinputfile(self, project, inputtemplate, sourcefile, **kwargs):
        """Add/upload an input file to the CLAM service. Supports proper file upload streaming.

        project - the ID of the project you want to add the file to.
        inputtemplate - The input template you want to use to add this file (InputTemplate instance)
        sourcefile - The file you want to add: string containing a filename (or instance of ``file``)

        Keyword arguments (optional but recommended!):
            * ``filename`` - the filename on the server (will be same as sourcefile if not specified)
            * ``metadata`` - A metadata object.
            * ``metafile`` - A metadata file (filename)

        Any other keyword arguments will be passed as metadata and matched with the input template's parameters.

        Example::

            client.addinputfile("myproject", "someinputtemplate", "/path/to/local/file")

        With metadata, assuming such metadata parameters are defined::

            client.addinputfile("myproject", "someinputtemplate", "/path/to/local/file", parameter1="blah", parameterX=3.5)

        """
        if isinstance( inputtemplate, str) or (sys.version < '3' and isinstance( inputtemplate, unicode)): #pylint: disable=undefined-variable
            data = self.get(project) #causes an extra query to server
            inputtemplate = data.inputtemplate(inputtemplate)
        elif not isinstance(inputtemplate, clam.common.data.InputTemplate):
            raise Exception("inputtemplate must be instance of InputTemplate. Get from CLAMData.inputtemplate(id)")

        if not isinstance(sourcefile, IOBase):
            sourcefile = open(sourcefile,'rb')
            if 'filename' in kwargs:
                filename = self.getinputfilename(inputtemplate, kwargs['filename'])
            else:
                filename = self.getinputfilename(inputtemplate, os.path.basename(sourcefile.name) )

        data = {"file": (filename,sourcefile,inputtemplate.formatclass.mimetype), 'inputtemplate': inputtemplate.id}
        for key, value in kwargs.items():
            if key == 'filename':
                pass #nothing to do
            elif key == 'metadata':
                assert isinstance(value, clam.common.data.CLAMMetaData)
                data['metadata'] =  value.xml()
            elif key == 'metafile':
                data['metafile'] = open(value,'rb')
            else:
                data[key] = value


        requestparams = self.initrequest(data)
        if 'auth'in requestparams:
            #TODO: streaming support doesn't work with authentication unfortunately, disabling streaming for now:
            del data['file']
            requestparams['data'] = data
            requestparams['files'] = [('file', (filename,sourcefile, inputtemplate.formatclass.mimetype))]
            if 'metafile' in kwargs:
                del data['metafile']
                requestparams['files'].append(('metafile',('.'+ filename + '.METADATA', open(kwargs['metafile'],'rb'), 'text/xml')))
        else:
            #streaming support
            encodeddata = MultipartEncoder(fields=requestparams['data']) #from requests-toolbelt, necessary for streaming support
            requestparams['data'] = encodeddata
            requestparams['headers']['Content-Type'] = encodeddata.content_type
        r = requests.post(self.url + project + '/input/' + filename,**requestparams)
        sourcefile.close()

        if r.status_code == 400:
            raise clam.common.data.BadRequest()
        elif r.status_code == 401:
            raise clam.common.data.AuthRequired()
        elif r.status_code == 403:
            if r.text[0] == '<':
                #XML response
                return self._parseupload(r.text)
            else:
                raise clam.common.data.PermissionDenied(r.text)
        elif r.status_code == 404:
            raise clam.common.data.NotFound(r.text)
        elif r.status_code == 500:
            raise clam.common.data.ServerError(r.text)
        elif r.status_code == 405:
            raise clam.common.data.ServerError("Server returned 405: Method not allowed for POST on " + self.url + project + '/input/' + filename)
        elif r.status_code == 408:
            raise clam.common.data.TimeOut()
        elif not (r.status_code >= 200 and r.status_code <= 299):
            raise Exception("An error occured, return code " + str(r.status_code))

        return self._parseupload(r.text)