Source code for spyne.decorator

# spyne - Copyright (C) Spyne contributors.
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301

"""The ``spyne.decorator`` module contains the the @srpc decorator and its
helper methods. The @srpc decorator is responsible for tagging methods as remote
procedure calls extracting method's input and output types.

It's possible to create custom decorators that wrap the @srpc decorator in order
to have a more elegant way of passing frequently-used parameter values. The @rpc
decorator is a simple example of this.

import spyne.const.xml_ns

from copy import copy

from spyne import MethodDescriptor

# Empty means empty input, bare output. Doesn't say anything about response
# being empty
from spyne._base import BODY_STYLE_EMPTY
from spyne._base import BODY_STYLE_WRAPPED
from spyne._base import BODY_STYLE_BARE

from spyne.model.complex import ComplexModel
from spyne.model.complex import TypeInfo

from spyne.const import add_request_suffix

def _produce_input_message(f, params, kparams, in_message_name,
                           in_variable_names, no_ctx, no_self, args):
    _body_style = _validate_body_style(kparams)

    arg_start = 0
    if no_ctx is False:
        arg_start += 1
    if no_self is False:
        arg_start += 1

    if args is None:
            argcount = f.__code__.co_argcount
            args = f.__code__.co_varnames[arg_start:argcount]

        except AttributeError:
            raise TypeError(
                "It's not possible to instrospect builtins. You must pass a "
                "sequence of argument names as the '_args' argument to the "
                "rpc decorator to manually denote the arguments that this "
                "function accepts."

        if len(params) != len(args):
            raise Exception("%r function has %d argument(s) but its decorator "
                            "has %d." % (f.__name__, len(args), len(params)))

        args = copy(args)
        if len(params) != len(args):
            raise Exception("%r function has %d argument(s) but the _args "
                            "argument has %d." % (
                            f.__name__, len(args), len(params)))

    in_params = TypeInfo()
    for k, v in zip(args, params):
        k = in_variable_names.get(k, k)
        in_params[k] = v

    ns = spyne.const.xml_ns.DEFAULT_NS
    if in_message_name.startswith("{"):
        ns, _, in_message_name = in_message_name[1:].partition("}")

    message = None
    if _body_style == 'bare':
        if len(in_params) > 1:
            raise Exception("body_style='bare' can handle at most one function "
        if len(in_params) == 0:
            message = ComplexModel.produce(type_name=in_message_name,
                                           namespace=ns, members=in_params)
            message, = in_params.values()
            message = message.customize(sub_name=in_message_name, sub_ns=ns)
            assert message.Attributes.sub_name is not None

        message = ComplexModel.produce(type_name=in_message_name,
                                       namespace=ns, members=in_params)
        message.__namespace__ = ns

    return message

def _validate_body_style(kparams):
    _body_style = kparams.get('_body_style')
    _soap_body_style = kparams.get('_soap_body_style')

    if _body_style is None:
        _body_style = 'wrapped'
    elif not (_body_style in ('wrapped', 'bare')):
        raise ValueError("body_style must be one of ('wrapped', 'bare')")
    elif _soap_body_style == 'document':
        _body_style = 'wrapped'
    elif _soap_body_style == 'rpc':
        _body_style = 'bare'
    elif _soap_body_style is None:
        raise ValueError("soap_body_style must be one of ('rpc', 'document')")

    assert _body_style in ('wrapped', 'bare')

    return _body_style

def _produce_output_message(func_name, kparams):
    """Generate an output message for "rpc"-style API methods.

    This message is a wrapper to the declared return type.

    _returns = kparams.get('_returns')
    _body_style = _validate_body_style(kparams)
    _out_message_name = kparams.get('_out_message_name', '%s%s' %
                                       (func_name, spyne.const.RESPONSE_SUFFIX))

    out_params = TypeInfo()

    if _returns and _body_style == 'wrapped':
        if isinstance(_returns, (list, tuple)):
            default_names = ['%s%s%d'% (func_name, spyne.const.RESULT_SUFFIX, i)
                                                  for i in range(len(_returns))]

            _out_variable_names = kparams.get('_out_variable_names',

            assert (len(_returns) == len(_out_variable_names))

            var_pair = zip(_out_variable_names, _returns)
            out_params = TypeInfo(var_pair)

            _out_variable_name = kparams.get('_out_variable_name',
                                '%s%s' % (func_name, spyne.const.RESULT_SUFFIX))

            out_params[_out_variable_name] = _returns

    ns = spyne.const.xml_ns.DEFAULT_NS
    if _out_message_name.startswith("{"):
        ns = _out_message_name[1:].partition("}")[0]

    if _body_style == 'bare' and _returns is not None:
        message = _returns.customize(sub_name=_out_message_name, sub_ns=ns)

        message = ComplexModel.produce(type_name=_out_message_name,
                                               namespace=ns, members=out_params)

        message.Attributes._wrapper = True
        message.__namespace__ = ns  # FIXME: is this necessary?

    return message

[docs]def rpc(*params, **kparams): """Method decorator to tag a method as a remote procedure call in a :class:`spyne.service.ServiceBase` subclass. You should use the :class:`spyne.server.null.NullServer` transport if you want to call the methods directly. You can also use the 'function' attribute of the returned object to call the function itself. ``_operation_name`` vs ``_in_message_name``: Soap clients(SoapUI, Savon, suds) will use the operation name as the function name. The name of the input message(_in_message_name) is irrelevant when interfacing in this manner; this is because the clients mostly wrap around it. However, the soap xml request only uses the input message when posting with the soap server; the other protocols only use the input message as well. ``_operation_name`` cannot be used with ``_in_message_name``. :param _returns: Denotes The return type of the function. It can be a type or a sequence of types for functions that have multiple return values. :param _in_header: A type or an iterable of types that that this method accepts as incoming header. :param _out_header: A type or an iterable of types that that this method sends as outgoing header. :param _operation_name: The function's soap operation name. The operation and SoapAction names will be equal to the value of ``_operation_name``. Default is the function name. :param _in_message_name: The public name of the function's input message. Default is: ``_operation_name + REQUEST_SUFFIX``. :param _out_message_name: The public name of the function's output message. Default is: ``_operation_name + RESPONSE_SUFFIX``. :param _in_variable_names: The public names of the function arguments. It's a dict that maps argument names in the code to public ones. :param _out_variable_name: The public name of the function response object. It's a string. Ignored when ``_body_style != 'wrapped'`` or ``_returns`` is a sequence. :param _out_variable_names: The public name of the function response object. It's a sequence of strings. Ignored when ``_body_style != 'wrapped'`` or or ``_returns`` is not a sequence. Must be the same length as ``_returns``. :param _body_style: One of ``('bare', 'wrapped')``. Default: ``'wrapped'``. In wrapped mode, wraps response objects in an additional class. :param _soap_body_style: One of ('rpc', 'document'). Default ``'document'``. ``_soap_body_style='document'`` is an alias for ``_body_style='wrapped'``. ``_soap_body_style='rpc'`` is an alias for ``_body_style='bare'``. :param _port_type: Soap port type string. :param _no_ctx: Don't pass implicit ctx object to the user method. :param _no_self: This method does not get an implicit 'self' argument (before any other argument, including ctx). :param _udp: Short for UserDefinedProperties, you can use this to mark the method with arbitrary metadata. :param _aux: The auxiliary backend to run this method. ``None`` if primary. :param _throws: A sequence of exceptions that this function can throw. This has no real functionality besides publishing this information in interface documents. :param _args: the name of the arguments to expose. :param _service_class: A :class:`ServiceBase` subclass, if you feel like overriding it. """ def explain(f): def explain_method(*args, **kwargs): function_name = kwargs['_default_function_name'] _is_callback = kparams.get('_is_callback', False) _is_async = kparams.get('_is_async', False) _mtom = kparams.get('_mtom', False) _in_header = kparams.get('_in_header', None) _out_header = kparams.get('_out_header', None) _port_type = kparams.get('_soap_port_type', None) _no_ctx = kparams.get('_no_ctx', False) _no_self = kparams.get('_no_self', True) _udp = kparams.get('_udp', None) _aux = kparams.get('_aux', None) _pattern = kparams.get("_pattern", None) _patterns = kparams.get("_patterns", []) _args = kparams.get("_args", None) _translations = kparams.get("_translations", None) _when = kparams.get("_when", None) _service_class = kparams.get("_service_class", None) _href = kparams.get("_href", None) if _no_self: from spyne.model import SelfReference if SelfReference in params: raise ValueError("SelfReference can't be used in @rpc") if SelfReference in kparams.values(): raise ValueError("SelfReference can't be used in @rpc") _faults = None if ('_faults' in kparams) and ('_throws' in kparams): raise ValueError("only one of '_throws ' or '_faults' arguments" "should be given, as they're synonyms.") elif '_faults' in kparams: _faults = kparams.get('_faults', None) elif '_throws' in kparams: _faults = kparams.get('_throws', None) _in_message_name_override = not ('_in_message_name' in kparams) _in_message_name = kparams.get('_in_message_name', function_name) _operation_name = kparams.get('_operation_name', function_name) if _operation_name != function_name and _in_message_name != function_name: raise ValueError( "only one of '_operation_name' and '_in_message_name' " "arguments should be given") if _in_message_name == function_name: _in_message_name = add_request_suffix(_operation_name) _in_variable_names = kparams.get('_in_variable_names', {}) in_message = _produce_input_message(f, params, kparams, _in_message_name, _in_variable_names, _no_ctx, _no_self, _args) _out_message_name_override = not ('_out_message_name' in kparams) out_message = _produce_output_message(function_name, kparams) doc = getattr(f, '__doc__') if _pattern is not None and _patterns != []: raise ValueError("only one of '_pattern' and '_patterns' " "arguments should be given") if _pattern is not None: _patterns = [_pattern] body_style = BODY_STYLE_WRAPPED if _validate_body_style(kparams) == 'bare': body_style = BODY_STYLE_BARE t = in_message from spyne.model import ComplexModelBase if issubclass(t, ComplexModelBase) and len(t._type_info) == 0: body_style = BODY_STYLE_EMPTY retval = MethodDescriptor(f, in_message, out_message, doc, _is_callback, _is_async, _mtom, _in_header, _out_header, _faults, port_type=_port_type, no_ctx=_no_ctx, udp=_udp, class_key=function_name, aux=_aux, patterns=_patterns, body_style=body_style, args=_args, operation_name=_operation_name, no_self=_no_self, translations=_translations, when=_when, in_message_name_override=_in_message_name_override, out_message_name_override=_out_message_name_override, service_class=_service_class, href=_href, ) if _patterns is not None: for p in _patterns: p.hello(retval) return retval explain_method.__doc__ = f.__doc__ explain_method._is_rpc = True return explain_method return explain
[docs]def srpc(*params, **kparams): """Method decorator to tag a method as a remote procedure call. See :func:`spyne.decorator.rpc` for detailed information. The initial "s" stands for "static". In Spyne terms, that means no implicit first argument is passed to the user callable, which really means the method is "stateless" rather than static. It's meant to be used for existing functions that can't be changed. """ kparams["_no_ctx"] = True return rpc(*params, **kparams)
def mrpc(*params, **kparams): kparams["_no_self"] = False return rpc(*params, **kparams)