exception handler

.gitignore

@@ -257,4 +257,4 @@ fabric.properties
 # End of https://www.gitignore.io/api/python,django,pycharm
 
 .idea/*
-courier
\ No newline at end of file
+courier/settings_local.py
\ No newline at end of file

courier/db_routers.py

+# -*- coding: utf-8 -*-
+from django.conf import settings
+
+
+class MessageRouter(object):
+    MODEL_PREFIXS = 'api.models.message'
+    TABLES = ['api_conversation', 'api_conversationuserstatus', 'api_message', 'api_conversationtags']
+
+    def validate(self, model):
+        return model.__module__.startswith(self.MODEL_PREFIXS) and model._meta.db_table in self.TABLES
+
+    def db_for_read(self, model, **hints):
+        if self.validate(model):
+            return getattr(settings, 'MESSAGE_SLAVE_DB_NAME', settings.MESSAGE_DB_NAME)
+        return None
+
+    def db_for_write(self, model, **hints):
+        if self.validate(model):
+            return settings.MESSAGE_DB_NAME
+        return None
+
+    def allow_relation(self, obj1, obj2, **hints):
+        if self.validate(obj1) and self.validate(obj2):
+            return True
+        return None
+
+    def allow_migrate(self, db, app_label, model_name=None, **hints):
+        return True

extension/types.py

@@ -2,6 +2,5 @@
 from gm_types.utils.enum import Enum, unique
 
 
-class CourierError(int, Enum):
-    pass
-
+class Error(int, Enum):
+    PARAMS_INVALID = (10001, '非法参数')
\ No newline at end of file

message/views.py

@@ -11,7 +11,9 @@ from adapter.old_system import bind_prefix
 from adapter.rpcd.exceptions import RPCPermanentError
 from api.models.message import ConversationUserStatus
 from rpc import gaia_client
-from rpc_framework.decorators import rpc_view
+from rpc_framework.context import RPCViewContext
+from rpc_framework.decorators import rpc_view, interceptor_classes
+from rpc_framework.interceptors import CalleeParametersInterceptor
 from search.utils import search_conversation_from_es
 from services.unread.stat import UserUnread
 
@@ -234,7 +236,6 @@ def message_conversation_list_v3(user_ids: List[int],
 
 
 @rpc_view('message/conversation/can_send')
-def check_can_send_message(context, target_uid: str) -> Dict:
-    # print(context.session_id)
-    print('+++', context, dir(context), context._context.session_id)
+@interceptor_classes([CalleeParametersInterceptor])
+def check_can_send_message(context: RPCViewContext, target_uid: str) -> Dict:
     return {'a': 'b'}

requirements.txt

@@ -18,3 +18,4 @@ elasticsearch==2.3.0
 kafka-python==1.4.7
 gunicorn==20.0.4
 #djangorestframework==3.11.0
+pydantic==1.3
\ No newline at end of file

rpc_framework/context.py

@@ -3,7 +3,9 @@ import sys
 from contextlib import contextmanager
 from typing import Optional, Tuple
 
+from gm_logging import RequestInfo
 from gm_rpcd.internals.context import Context
+from gm_rpcd.internals.protocol.request import Request
 
 from rpc_framework import exceptions
 from rpc_framework.settings import api_settings
@@ -28,6 +30,26 @@ def wrap_attributeerrors():
 
 
 class RPCViewContext(object):
+    '''
+    Wrapper allowing to enhance a `gm_rpcd.internals.context.Context` instance.
+
+    Kwargs:
+        - context(gm_rpcd.internals.context.Context). The original context instance.
+        - parsers_classes(list/tuple). The parsers to use for parsing the
+          request content.
+        - authentication_classes(list/tuple). The authentications used to try
+          authenticating the request's user.
+
+    Usage Examples:
+        inspect property of `gm_rpcd.internals.context.Context` instance:
+            print(context.request.request_id)
+            print(context.request.session_id)
+            print(context.request.method)
+            print(context.request.params)
+            print(context.request.environment)
+            print(context.request_info.user_id)
+
+    '''
     def __init__(self,
                  context: Context,
                  authenticators: Optional[Tuple]=None,
@@ -62,6 +84,14 @@ class RPCViewContext(object):
         self._user = value
         self._request.user = value
 
+    @property
+    def request(self) -> Optional[Request]:
+        return getattr(self._context, '_Context__request', None)
+
+    @property
+    def request_info(self) -> Optional[RequestInfo]:
+        return getattr(self._context, '_Context__request_info', None)
+
     def _authenticate(self):
         """
         Attempt to authenticate the request using each authentication instance
@@ -99,4 +129,14 @@ class RPCViewContext(object):
         else:
             self.auth = None
 
+    def __getattr__(self, attr):
+        """
+        If an attribute does not exist on this instance, then we also attempt
+        to proxy it to the underlying HttpRequest object.
+        """
+        try:
+            return getattr(self._request, attr)
+        except AttributeError:
+            return self.__getattribute__(attr)
+
 

rpc_framework/decorators.py

@@ -19,7 +19,9 @@ def rpc_view(endpoint):
         WrappedAPIView.endpoint = endpoint
         def handler(self, context, *args, **kwargs):
             return func(context, *args, **kwargs)
+
         setattr(WrappedAPIView, 'handler', handler)
+        setattr(WrappedAPIView, 'callee', func)
 
         WrappedAPIView.__name__ = func.__name__
         WrappedAPIView.__module__ = func.__module__
@@ -30,6 +32,9 @@ def rpc_view(endpoint):
         WrappedAPIView.parser_classes = getattr(func, 'parser_classes',
                                                 RPCView.parser_classes)
 
+        WrappedAPIView.interceptor_classes = getattr(func, 'interceptor_classes',
+                                                     RPCView.interceptor_classes)
+
         WrappedAPIView.authentication_classes = getattr(func, 'authentication_classes',
                                                         RPCView.authentication_classes)
 
@@ -44,3 +49,52 @@ def rpc_view(endpoint):
         return WrappedAPIView.rpc_bind()
 
     return decorator
+
+def renderer_classes(renderer_classes):
+    def decorator(func):
+        func.renderer_classes = renderer_classes
+        return func
+    return decorator
+
+
+def parser_classes(parser_classes):
+    def decorator(func):
+        func.parser_classes = parser_classes
+        return func
+    return decorator
+
+
+def interceptor_classes(interceptor_classes):
+    def decorator(func):
+        func.interceptor_classes = interceptor_classes
+        return func
+
+    return decorator
+
+
+def authentication_classes(authentication_classes):
+    def decorator(func):
+        func.authentication_classes = authentication_classes
+        return func
+    return decorator
+
+
+def throttle_classes(throttle_classes):
+    def decorator(func):
+        func.throttle_classes = throttle_classes
+        return func
+    return decorator
+
+
+def permission_classes(permission_classes):
+    def decorator(func):
+        func.permission_classes = permission_classes
+        return func
+    return decorator
+
+
+def schema(view_inspector):
+    def decorator(func):
+        func.schema = view_inspector
+        return func
+    return decorator

rpc_framework/exceptions.py

 # -*- coding: utf-8 -*-
+from abc import ABCMeta, abstractmethod
+from typing import Sequence
+
+from gm_rpcd.internals.exceptions import RPCDFaultException
+from pydantic import ValidationError, create_model
+from pydantic.error_wrappers import ErrorList
+
+from extension.types import Error
+
+
+def _check_methods(C, *methods):
+    mro = C.__mro__
+    for method in methods:
+        for B in mro:
+            if method in B.__dict__:
+                if B.__dict__[method] is None:
+                    return NotImplemented
+                break
+        else:
+            return NotImplemented
+    return True
+
+
+class RPCViewBaseException(metaclass=ABCMeta):
+    code: int
+    message: str
+
+    __slots__ = ()
+
+    @classmethod
+    def __subclasshook__(cls, C):
+        if cls is RPCViewBaseException:
+            return _check_methods(C, "as_rpcd_fault")
+        return NotImplemented
+
+    @abstractmethod
+    def as_rpcd_fault(self):
+        return RPCDFaultException(error=self.error, message=self.message)
+
+
+RequestErrorModel = create_model("Request")
+
+class CalleeTypeHintValidationError(ValidationError):
+    def __init__(self, errors: Sequence[ErrorList]) -> None:
+        return super().__init__(errors, RequestErrorModel)
+
+    def as_rpcd_fault(self):
+        return RPCDFaultException(code=Error.PARAMS_INVALID, message=self.json())
 
-class RPCViewBaseException(Exception):
-    pass

rpc_framework/inspector.py

+# -*- coding: utf-8 -*-
+import inspect
+from typing import Callable, Dict, Any
+
+from pydantic.typing import ForwardRef, evaluate_forwardref
+
+
+def get_typed_annotation(param: inspect.Parameter, globalns: Dict[str, Any]) -> Any:
+    annotation = param.annotation
+    if isinstance(annotation, str):
+        annotation = ForwardRef(annotation)
+        annotation = evaluate_forwardref(annotation, globalns, globalns)
+    return annotation
+
+
+def get_typed_signature(call: Callable) -> inspect.Signature:
+    signature = inspect.signature(call)
+    globalns = getattr(call, "__globals__", {})
+    typed_params = [
+        inspect.Parameter(
+            name=param.name,
+            kind=param.kind,
+            default=param.default,
+            annotation=get_typed_annotation(param, globalns),
+        )
+        for param in signature.parameters.values()
+    ]
+    typed_signature = inspect.Signature(typed_params)
+    return typed_signature
+
+
+if __name__ == '__main__':
+    def a(a: int=10):
+        pass
+    res = get_typed_signature(a)
+    print(res, type(res))
\ No newline at end of file

rpc_framework/interceptors.py

+# -*- coding: utf-8 -*-
+import inspect
+from abc import ABCMeta, abstractmethod
+from copy import deepcopy
+from typing import Type, Any, List, Optional, Dict, Tuple
+
+from pydantic import BaseModel, BaseConfig, MissingError
+from pydantic.error_wrappers import ErrorWrapper
+from pydantic.fields import ModelField, Required, FieldInfo, SHAPE_SINGLETON, \
+    SHAPE_LIST, SHAPE_SET, SHAPE_TUPLE, SHAPE_SEQUENCE, SHAPE_TUPLE_ELLIPSIS
+from pydantic.schema import get_annotation_from_field_info
+from pydantic.utils import lenient_issubclass
+
+from rpc_framework import params
+from rpc_framework.context import RPCViewContext
+from rpc_framework.exceptions import CalleeTypeHintValidationError
+from rpc_framework.inspector import get_typed_signature
+from rpc_framework.views import RPCView
+
+
+sequence_shapes = {
+    SHAPE_LIST,
+    SHAPE_SET,
+    SHAPE_TUPLE,
+    SHAPE_SEQUENCE,
+    SHAPE_TUPLE_ELLIPSIS,
+}
+
+sequence_types = (list, set, tuple)
+
+
+class Interceptor(metaclass=ABCMeta):
+
+    __slots__ = ()
+
+    @abstractmethod
+    def intercept(self, context, rpc_view):
+        pass
+
+
+def get_field_info(field: ModelField) -> FieldInfo:
+    return field.field_info
+
+
+def is_scalar_field(field: ModelField) -> bool:
+    field_info = get_field_info(field)
+    if not (
+        field.shape == SHAPE_SINGLETON
+        and not lenient_issubclass(field.type_, BaseModel)
+        and not lenient_issubclass(field.type_, sequence_types + (dict,))
+        and not isinstance(field_info, params.Body)
+    ):
+        return False
+    if field.sub_fields:
+        if not all(is_scalar_field(f) for f in field.sub_fields):
+            return False
+    return True
+
+
+def get_param_field(
+    *,
+    param: inspect.Parameter,
+    param_name: str,
+    default_field_info: Type[params.Param] = params.Param,
+    force_type: params.ParamTypes = None,
+    ignore_default: bool = False,
+) -> ModelField:
+    default_value = Required
+    had_schema = False
+    if not param.default == param.empty and ignore_default is False:
+        default_value = param.default
+    if isinstance(default_value, FieldInfo):
+        had_schema = True
+        field_info = default_value
+        default_value = field_info.default
+        if (
+            isinstance(field_info, params.Param)
+            and getattr(field_info, "in_", None) is None
+        ):
+            field_info.in_ = default_field_info.in_
+        if force_type:
+            field_info.in_ = force_type  # type: ignore
+    else:
+        field_info = default_field_info(default_value)
+    required = default_value == Required
+    annotation: Any = Any
+    if not param.annotation == param.empty:
+        annotation = param.annotation
+    annotation = get_annotation_from_field_info(annotation, field_info, param_name)
+    if not field_info.alias and getattr(field_info, "convert_underscores", None):
+        alias = param.name.replace("_", "-")
+    else:
+        alias = field_info.alias or param.name
+    field = ModelField(
+        name=param.name,
+        type_=annotation,
+        default=None if required else default_value,
+        alias=alias,
+        required=required,
+        model_config=BaseConfig,
+        class_validators={},
+        field_info=field_info,
+    )
+    field.required = required
+    if not had_schema and not is_scalar_field(field=field):
+        field.field_info = params.Body(field_info.default)
+
+    return field
+
+
+def get_callee_field_list(callee):
+    param_field_list = []
+
+    endpoint_signature = get_typed_signature(callee)
+    signature_params = endpoint_signature.parameters
+    if inspect.isgeneratorfunction(callee) or inspect.isasyncgenfunction(callee):
+        # check_dependency_contextmanagers()
+        pass
+
+    for param_name, param in signature_params.items():
+        param_field = get_param_field(
+            param=param, default_field_info=params.Query, param_name=param_name
+        )
+        param_field_list.append(param_field)
+    return param_field_list
+
+
+def is_null_subfield_in_pack(packed_field_info, subfield, subfield_value):
+    return (isinstance(packed_field_info, params.Form) and subfield_value == "") or \
+           (
+                   isinstance(packed_field_info, params.Form)
+                   and subfield.shape in sequence_shapes
+                   and len(subfield_value) == 0
+           )
+
+
+def check_parameters_fit_signature(
+    required_params: List[ModelField],
+    received_body: Optional[Dict],
+    is_pack_params: bool=False
+) -> Tuple[Dict[str, Any], List[ErrorWrapper]]:
+    values = {}
+    errors = []
+
+    if required_params:
+        if is_pack_params:
+            packed_field = required_params[0]
+            packed_field_info = get_field_info(packed_field)
+            embed = getattr(packed_field_info, "embed", None)
+            if len(required_params) == 1 and not embed:
+                received_body = {packed_field.alias: received_body}
+
+        for field in required_params:
+            value: Any = None
+            if received_body is not None:
+                value = received_body.get(field.alias)
+            if (
+                value is None
+                or (is_pack_params and is_null_subfield_in_pack(packed_field_info, field, value))
+            ):
+                if field.required:
+                    errors.append(
+                        ErrorWrapper(MissingError(), loc=("body", field.alias))
+                    )
+                else:
+                    values[field.name] = deepcopy(field.default)
+                continue
+            print(value, values)
+            v_, errors_ = field.validate(value, values, loc=("body", field.alias))
+            if isinstance(errors_, ErrorWrapper):
+                errors.append(errors_)
+            elif isinstance(errors_, list):
+                errors.extend(errors_)
+            else:
+                values[field.name] = v_
+    return values, errors
+
+
+class CalleeParametersInterceptor(Interceptor):
+
+    def intercept(self, context: RPCViewContext, rpc_view: RPCView) -> bool:
+        callee_field_list = get_callee_field_list(rpc_view.callee)
+        validated_values, errors = check_parameters_fit_signature(callee_field_list, context.request.params)
+        if errors:
+            raise CalleeTypeHintValidationError(errors)
+        return True
\ No newline at end of file

rpc_framework/params.py

+from enum import Enum
+from typing import Any, Callable, Sequence
+
+from pydantic.fields import FieldInfo
+
+
+class ParamTypes(Enum):
+    query = "query"
+    header = "header"
+    path = "path"
+    cookie = "cookie"
+
+
+class Param(FieldInfo):
+    in_: ParamTypes
+
+    def __init__(
+        self,
+        default: Any,
+        *,
+        alias: str = None,
+        title: str = None,
+        description: str = None,
+        gt: float = None,
+        ge: float = None,
+        lt: float = None,
+        le: float = None,
+        min_length: int = None,
+        max_length: int = None,
+        regex: str = None,
+        deprecated: bool = None,
+        **extra: Any,
+    ):
+        self.deprecated = deprecated
+        super().__init__(
+            default,
+            alias=alias,
+            title=title,
+            description=description,
+            gt=gt,
+            ge=ge,
+            lt=lt,
+            le=le,
+            min_length=min_length,
+            max_length=max_length,
+            regex=regex,
+            **extra,
+        )
+
+
+class Path(Param):
+    in_ = ParamTypes.path
+
+    def __init__(
+        self,
+        default: Any,
+        *,
+        alias: str = None,
+        title: str = None,
+        description: str = None,
+        gt: float = None,
+        ge: float = None,
+        lt: float = None,
+        le: float = None,
+        min_length: int = None,
+        max_length: int = None,
+        regex: str = None,
+        deprecated: bool = None,
+        **extra: Any,
+    ):
+        self.in_ = self.in_
+        super().__init__(
+            ...,
+            alias=alias,
+            title=title,
+            description=description,
+            gt=gt,
+            ge=ge,
+            lt=lt,
+            le=le,
+            min_length=min_length,
+            max_length=max_length,
+            regex=regex,
+            deprecated=deprecated,
+            **extra,
+        )
+
+
+class Query(Param):
+    in_ = ParamTypes.query
+
+    def __init__(
+        self,
+        default: Any,
+        *,
+        alias: str = None,
+        title: str = None,
+        description: str = None,
+        gt: float = None,
+        ge: float = None,
+        lt: float = None,
+        le: float = None,
+        min_length: int = None,
+        max_length: int = None,
+        regex: str = None,
+        deprecated: bool = None,
+        **extra: Any,
+    ):
+        super().__init__(
+            default,
+            alias=alias,
+            title=title,
+            description=description,
+            gt=gt,
+            ge=ge,
+            lt=lt,
+            le=le,
+            min_length=min_length,
+            max_length=max_length,
+            regex=regex,
+            deprecated=deprecated,
+            **extra,
+        )
+
+
+class Header(Param):
+    in_ = ParamTypes.header
+
+    def __init__(
+        self,
+        default: Any,
+        *,
+        alias: str = None,
+        convert_underscores: bool = True,
+        title: str = None,
+        description: str = None,
+        gt: float = None,
+        ge: float = None,
+        lt: float = None,
+        le: float = None,
+        min_length: int = None,
+        max_length: int = None,
+        regex: str = None,
+        deprecated: bool = None,
+        **extra: Any,
+    ):
+        self.convert_underscores = convert_underscores
+        super().__init__(
+            default,
+            alias=alias,
+            title=title,
+            description=description,
+            gt=gt,
+            ge=ge,
+            lt=lt,
+            le=le,
+            min_length=min_length,
+            max_length=max_length,
+            regex=regex,
+            deprecated=deprecated,
+            **extra,
+        )
+
+
+class Cookie(Param):
+    in_ = ParamTypes.cookie
+
+    def __init__(
+        self,
+        default: Any,
+        *,
+        alias: str = None,
+        title: str = None,
+        description: str = None,
+        gt: float = None,
+        ge: float = None,
+        lt: float = None,
+        le: float = None,
+        min_length: int = None,
+        max_length: int = None,
+        regex: str = None,
+        deprecated: bool = None,
+        **extra: Any,
+    ):
+        super().__init__(
+            default,
+            alias=alias,
+            title=title,
+            description=description,
+            gt=gt,
+            ge=ge,
+            lt=lt,
+            le=le,
+            min_length=min_length,
+            max_length=max_length,
+            regex=regex,
+            deprecated=deprecated,
+            **extra,
+        )
+
+
+class Body(FieldInfo):
+    def __init__(
+        self,
+        default: Any,
+        *,
+        embed: bool = False,
+        media_type: str = "application/json",
+        alias: str = None,
+        title: str = None,
+        description: str = None,
+        gt: float = None,
+        ge: float = None,
+        lt: float = None,
+        le: float = None,
+        min_length: int = None,
+        max_length: int = None,
+        regex: str = None,
+        **extra: Any,
+    ):
+        self.embed = embed
+        self.media_type = media_type
+        super().__init__(
+            default,
+            alias=alias,
+            title=title,
+            description=description,
+            gt=gt,
+            ge=ge,
+            lt=lt,
+            le=le,
+            min_length=min_length,
+            max_length=max_length,
+            regex=regex,
+            **extra,
+        )
+
+
+class Form(Body):
+    def __init__(
+        self,
+        default: Any,
+        *,
+        media_type: str = "application/x-www-form-urlencoded",
+        alias: str = None,
+        title: str = None,
+        description: str = None,
+        gt: float = None,
+        ge: float = None,
+        lt: float = None,
+        le: float = None,
+        min_length: int = None,
+        max_length: int = None,
+        regex: str = None,
+        **extra: Any,
+    ):
+        super().__init__(
+            default,
+            embed=True,
+            media_type=media_type,
+            alias=alias,
+            title=title,
+            description=description,
+            gt=gt,
+            ge=ge,
+            lt=lt,
+            le=le,
+            min_length=min_length,
+            max_length=max_length,
+            regex=regex,
+            **extra,
+        )
+
+
+class File(Form):
+    def __init__(
+        self,
+        default: Any,
+        *,
+        media_type: str = "multipart/form-data",
+        alias: str = None,
+        title: str = None,
+        description: str = None,
+        gt: float = None,
+        ge: float = None,
+        lt: float = None,
+        le: float = None,
+        min_length: int = None,
+        max_length: int = None,
+        regex: str = None,
+        **extra: Any,
+    ):
+        super().__init__(
+            default,
+            media_type=media_type,
+            alias=alias,
+            title=title,
+            description=description,
+            gt=gt,
+            ge=ge,
+            lt=lt,
+            le=le,
+            min_length=min_length,
+            max_length=max_length,
+            regex=regex,
+            **extra,
+        )
+
+
+class Depends:
+    def __init__(self, dependency: Callable = None, *, use_cache: bool = True):
+        self.dependency = dependency
+        self.use_cache = use_cache
+
+
+class Security(Depends):
+    def __init__(
+        self,
+        dependency: Callable = None,
+        *,
+        scopes: Sequence[str] = None,
+        use_cache: bool = True,
+    ):
+        super().__init__(dependency=dependency, use_cache=use_cache)
+        self.scopes = scopes or []

rpc_framework/result.py

+# # -*- coding: utf-8 -*-
+# class Result(dict):
+#     def __init__(self, raw_data=None, exception=False):
+#         self.raw_data = raw_data
+#         self.exception = exception
+#
+#     @property
+#     def value(self):
+#         if self.exception:
+#             return {}
+#         return self.raw_data
\ No newline at end of file

rpc_framework/settings.py

@@ -82,7 +82,7 @@ DEFAULTS = {
     # 'VIEW_DESCRIPTION_FUNCTION': 'rest_framework.views.get_view_description',
 
     # Exception handling
-    # 'EXCEPTION_HANDLER': 'rest_framework.views.exception_handler',
+    'EXCEPTION_HANDLER': 'rpc_framework.views.exception_handler',
     # 'NON_FIELD_ERRORS_KEY': 'non_field_errors',
 
     # Testing
@@ -140,7 +140,7 @@ IMPORT_STRINGS = [
     # 'DEFAULT_PAGINATION_CLASS',
     # 'DEFAULT_FILTER_BACKENDS',
     # 'DEFAULT_SCHEMA_CLASS',
-    # 'EXCEPTION_HANDLER',
+    'EXCEPTION_HANDLER',
     # 'TEST_REQUEST_RENDERER_CLASSES',
     # 'UNAUTHENTICATED_USER',
     # 'UNAUTHENTICATED_TOKEN',

rpc_framework/views.py

 # -*- coding: utf-8 -*-
+from django.db import connection, transaction
+
+from rpc_framework import exceptions
 from rpc_framework.context import RPCViewContext
 from rpc_framework.generic.base import RPCAbstractView
 from rpc_framework.settings import api_settings
 
 
+def set_rollback():
+    atomic_requests = connection.settings_dict.get('ATOMIC_REQUESTS', False)
+    if atomic_requests and connection.in_atomic_block:
+        transaction.set_rollback(True)
+
+
+def exception_handler(exc, wrapped_context) -> None:
+    if issubclass(exc.__class__, exceptions.RPCViewBaseException):
+        set_rollback()
+        raise exc.as_rpcd_fault() # type: RPCDFaultException
+
+    return None
+
+
 class RPCView(RPCAbstractView):
     # The following policies may be set at either globally, or per-view.
     # renderer_classes = api_settings.DEFAULT_RENDERER_CLASSES
@@ -38,6 +55,9 @@ class RPCView(RPCAbstractView):
         view.initkwargs = initkwargs
         return view
 
+    # Note: Views are made CSRF exempt from within `as_view` as to prevent
+    # accidental removal of this exemption in cases where `dispatch` needs to
+    # be overridden.
     def dispatch(self, context, *args, **kwargs):
         """
         `.dispatch()` is pretty much the same as Django's regular dispatch,
@@ -47,47 +67,21 @@ class RPCView(RPCAbstractView):
         self.kwargs = kwargs
         context = self.initialize_context(context, *args, **kwargs)
         self.context = context
-        # self.headers = self.default_response_headers  # deprecate?
 
         try:
             self.initial(context, *args, **kwargs)
 
             # Get the appropriate handler method
             handler = self.handler
-            response = handler(context, *args, **kwargs)
+            result = handler(context, *args, **kwargs)
 
         except Exception as exc:
-            print('+' * 10 , exc)
-            response = self.handle_exception(exc)
-
-        self.response = self.finalize_response(context, response, *args, **kwargs)
-        return self.response
-
+            print('error::', exc, type(exc))
+            result = self.handle_exception(exc)
 
+        self.result = self.finalize_response(context, result, *args, **kwargs)
+        return self.result
 
-    # @property
-    # def allowed_methods(self):
-    #     """
-    #     Wrap Django's private `_allowed_methods` interface in a public property.
-    #     """
-    #     return self._allowed_methods()
-    #
-    # @property
-    # def default_response_headers(self):
-    #     headers = {
-    #         'Allow': ', '.join(self.allowed_methods),
-    #     }
-    #     if len(self.renderer_classes) > 1:
-    #         headers['Vary'] = 'Accept'
-    #     return headers
-    #
-    # def http_method_not_allowed(self, request, *args, **kwargs):
-    #     """
-    #     If `request.method` does not correspond to a handler method,
-    #     determine what kind of exception to raise.
-    #     """
-    #     raise exceptions.MethodNotAllowed(request.method)
-    #
     # def permission_denied(self, request, message=None):
     #     """
     #     If request is not permitted, determine what kind of exception to raise.
@@ -137,19 +131,19 @@ class RPCView(RPCAbstractView):
     #         'kwargs': getattr(self, 'kwargs', {}),
     #         'request': getattr(self, 'request', None)
     #     }
-    #
-    # def get_exception_handler_context(self):
-    #     """
-    #     Returns a dict that is passed through to EXCEPTION_HANDLER,
-    #     as the `context` argument.
-    #     """
-    #     return {
-    #         'view': self,
-    #         'args': getattr(self, 'args', ()),
-    #         'kwargs': getattr(self, 'kwargs', {}),
-    #         'request': getattr(self, 'request', None)
-    #     }
-    #
+
+    def get_exception_handler_context_wrapper(self):
+        """
+        Returns a dict that is passed through to EXCEPTION_HANDLER,
+        as the `context` argument.
+        """
+        return {
+            'view': self,
+            'args': getattr(self, 'args', ()),
+            'kwargs': getattr(self, 'kwargs', {}),
+            'context': getattr(self, 'context', None)
+        }
+
     # def get_view_name(self):
     #     """
     #     Return the view name, as used in OPTIONS responses and in the
@@ -210,14 +204,14 @@ class RPCView(RPCAbstractView):
             self._negotiator = self.content_negotiation_class()
         return self._negotiator
 
-    # def get_exception_handler(self):
-    #     """
-    #     Returns the exception handler that this view uses.
-    #     """
-    #     return self.settings.EXCEPTION_HANDLER
-    #
-    # # API policy implementation methods
-    #
+    def get_exception_handler(self):
+        """
+        Returns the exception handler that this view uses.
+        """
+        return self.settings.EXCEPTION_HANDLER
+
+    # API policy implementation methods
+
     # def perform_content_negotiation(self, request, force=False):
     #     """
     #     Determine which renderer and media type to use render the response.
@@ -243,6 +237,14 @@ class RPCView(RPCAbstractView):
         # context.user
         return None
 
+    def perform_interceptor(self, context):
+        """
+        Check if the request should be permitted.
+        Raises an appropriate exception if the request is not permitted.
+        """
+        for interceptor in self.get_interceptors():
+            interceptor.intercept(context, self)
+
     def check_permissions(self, context):
         """
         Check if the request should be permitted.
@@ -326,39 +328,30 @@ class RPCView(RPCAbstractView):
         # request.version, request.versioning_scheme = version, scheme
 
         # Ensure that the incoming request is permitted
+        self.perform_interceptor(context)
         self.perform_authentication(context)
         self.check_permissions(context)
         self.check_throttles(context)
 
-    def finalize_response(self, context, response, *args, **kwargs):
-        return response
+    def finalize_response(self, context, result, *args, **kwargs):
+        return result
 
-    # def handle_exception(self, exc):
-    #     """
-    #     Handle any exception that occurs, by returning an appropriate response,
-    #     or re-raising the error.
-    #     """
-    #     if isinstance(exc, (exceptions.NotAuthenticated,
-    #                         exceptions.AuthenticationFailed)):
-    #         # WWW-Authenticate header for 401 responses, else coerce to 403
-    #         auth_header = self.get_authenticate_header(self.request)
-    #
-    #         if auth_header:
-    #             exc.auth_header = auth_header
-    #         else:
-    #             exc.status_code = status.HTTP_403_FORBIDDEN
-    #
-    #     exception_handler = self.get_exception_handler()
-    #
-    #     context = self.get_exception_handler_context()
-    #     response = exception_handler(exc, context)
-    #
-    #     if response is None:
+    def handle_exception(self, exc):
+        """
+        Handle any exception that occurs, by returning an appropriate response,
+        or re-raising the error.
+        """
+        exception_handler = self.get_exception_handler()
+
+        wrapped_context = self.get_exception_handler_context_wrapper()
+        result = exception_handler(exc, wrapped_context)
+
+        # if not result:
         #     self.raise_uncaught_exception(exc)
-    #
-    #     response.exception = True
-    #     return response
-    #
+
+        # result.exception = True
+        return result
+
     # def raise_uncaught_exception(self, exc):
     #     if settings.DEBUG:
     #         request = self.request
@@ -366,44 +359,3 @@ class RPCView(RPCAbstractView):
     #         use_plaintext_traceback = renderer_format not in ('html', 'api', 'admin')
     #         request.force_plaintext_errors(use_plaintext_traceback)
     #     raise exc
\ No newline at end of file
-    #
-    # # Note: Views are made CSRF exempt from within `as_view` as to prevent
-    # # accidental removal of this exemption in cases where `dispatch` needs to
-    # # be overridden.
-    # def dispatch(self, request, *args, **kwargs):
-    #     """
-    #     `.dispatch()` is pretty much the same as Django's regular dispatch,
-    #     but with extra hooks for startup, finalize, and exception handling.
-    #     """
-    #     self.args = args
-    #     self.kwargs = kwargs
-    #     request = self.initialize_request(request, *args, **kwargs)
-    #     self.request = request
-    #     self.headers = self.default_response_headers  # deprecate?
-    #
-    #     try:
-    #         self.initial(request, *args, **kwargs)
-    #
-    #         # Get the appropriate handler method
-    #         if request.method.lower() in self.http_method_names:
-    #             handler = getattr(self, request.method.lower(),
-    #                               self.http_method_not_allowed)
-    #         else:
-    #             handler = self.http_method_not_allowed
-    #
-    #         response = handler(request, *args, **kwargs)
-    #
-    #     except Exception as exc:
-    #         response = self.handle_exception(exc)
-    #
-    #     self.response = self.finalize_response(request, response, *args, **kwargs)
-    #     return self.response
-    #
-    # def options(self, request, *args, **kwargs):
-    #     """
-    #     Handler method for HTTP 'OPTIONS' request.
-    #     """
-    #     if self.metadata_class is None:
-    #         return self.http_method_not_allowed(request, *args, **kwargs)
-    #     data = self.metadata_class().determine_metadata(request, self)
-    #     return Response(data, status=status.HTTP_200_OK)
\ No newline at end of file