Source code for crossbar.bridge.rest.caller

#####################################################################################
#
#  Copyright (c) typedef int GmbH
#  SPDX-License-Identifier: EUPL-1.2
#
#####################################################################################

from autobahn.wamp.types import CallResult
from twisted.internet.defer import maybeDeferred

from crossbar._util import dump_json
from crossbar.bridge.rest.common import _CommonResource

__all__ = ("CallerResource",)




class CallerResource(_CommonResource):
    """
    A HTTP/POST to WAMP-Caller bridge.
    """



    def _process(self, request, event):
        if "procedure" not in event:
            return self._deny_request(request, 400, key="procedure", log_category="AR455")

        procedure = event.pop("procedure")

        args = event["args"] if "args" in event and event["args"] else []
        kwargs = event["kwargs"] if "kwargs" in event and event["kwargs"] else {}

        def _call(*args, **kwargs):
            return self._session.call(*args, **kwargs)

        d = maybeDeferred(_call, procedure, *args, **kwargs)

        def on_call_ok(value):
            # a WAMP procedure call result may have a single return value, but also
            # multiple, positional return values as well as keyword-based return values
            #
            if isinstance(value, CallResult):
                res = {}
                if value.results:
                    res["args"] = value.results
                if value.kwresults:
                    res["kwargs"] = value.kwresults
            else:
                res = {"args": [value]}

            body = dump_json(res, True).encode("utf8")

            return self._complete_request(request, 200, body, log_category="AR202")

        def on_call_error(err):
            # a WAMP procedure call returning with error should be forwarded
            # to the HTTP-requestor still successfully
            #
            return self._fail_request(request, failure=err, log_category="AR458")

        return d.addCallbacks(on_call_ok, on_call_error)