"""Class-based views."""
from functools import wraps
from typing import (
Any,
Awaitable,
Callable,
ClassVar,
Mapping,
Type,
cast,
no_type_check,
)
from faust.types import AppT, ModelT
from faust.types.web import ViewDecorator, ViewHandlerFun
from . import exceptions
from .base import Request, Response, Web
from .exceptions import WebError
__all__ = ['View', 'gives_model', 'takes_model']
_bytes = bytes # need alias for method named `bytes`
[docs]class View:
"""View (HTTP endpoint)."""
ServerError: ClassVar[Type[WebError]] = exceptions.ServerError
ValidationError: ClassVar[Type[WebError]] = exceptions.ValidationError
ParseError: ClassVar[Type[WebError]] = exceptions.ParseError
NotAuthenticated: ClassVar[Type[WebError]] = exceptions.NotAuthenticated
PermissionDenied: ClassVar[Type[WebError]] = exceptions.PermissionDenied
NotFound: ClassVar[Type[WebError]] = exceptions.NotFound
view_name: str
view_path: str
methods: Mapping[str, Callable[[Request], Awaitable]]
[docs] @classmethod
def from_handler(cls, fun: ViewHandlerFun) -> Type['View']:
if not callable(fun):
raise TypeError(f'View handler must be callable, not {fun!r}')
return type(fun.__name__, (cls,), {
'get': fun,
'__doc__': fun.__doc__,
'__module__': fun.__module__,
})
def __init__(self, app: AppT, web: Web) -> None:
self.app = app
self.web = web
self.methods = {
'head': self.head,
'get': self.get,
'post': self.post,
'patch': self.patch,
'delete': self.delete,
'put': self.put,
}
self.__post_init__()
def __post_init__(self) -> None:
...
async def __call__(self, request: Any) -> Any:
return await self.dispatch(request)
[docs] async def dispatch(self, request: Any) -> Any:
method = request.method.lower()
kwargs = request.match_info or {} # XXX Aiohttp specific
# we cast here since some subclasses take extra parameters
# from the URL route (match_info).
method = cast(Callable[..., Awaitable[Response]], self.methods[method])
try:
return await method(cast(Request, request), **kwargs)
except WebError as exc:
return await self.on_request_error(request, exc)
[docs] async def on_request_error(self,
request: Request,
exc: WebError) -> Response:
return self.error(exc.code, exc.detail, **exc.extra_context)
[docs] @no_type_check
async def head(self, request: Request, **kwargs: Any) -> Any:
return await self.get(request, **kwargs)
[docs] @no_type_check # subclasses change signature based on route match_info
async def get(self, request: Request, **kwargs: Any) -> Any:
raise exceptions.MethodNotAllowed('Method GET not allowed.')
[docs] @no_type_check # subclasses change signature based on route match_info
async def post(self, request: Request, **kwargs: Any) -> Any:
raise exceptions.MethodNotAllowed('Method POST not allowed.')
[docs] @no_type_check # subclasses change signature based on route match_info
async def put(self, request: Request, **kwargs: Any) -> Any:
raise exceptions.MethodNotAllowed('Method PUT not allowed.')
[docs] @no_type_check # subclasses change signature based on route match_info
async def patch(self, request: Request, **kwargs: Any) -> Any:
raise exceptions.MethodNotAllowed('Method PATCH not allowed.')
[docs] @no_type_check # subclasses change signature based on route match_info
async def delete(self, request: Request, **kwargs: Any) -> Any:
raise exceptions.MethodNotAllowed('Method DELETE not allowed.')
[docs] def text(self, value: str, *, content_type: str = None,
status: int = 200) -> Response:
return self.web.text(value, content_type=content_type, status=status)
[docs] def html(self, value: str, *, status: int = 200) -> Response:
return self.web.html(value, status=status)
[docs] def json(self, value: Any, *, status: int = 200) -> Response:
return self.web.json(value, status=status)
[docs] def bytes(self,
value: _bytes,
*,
content_type: str = None,
status: int = 200) -> Response:
return self.web.bytes(value, content_type=content_type, status=status)
[docs] async def read_request_content(self, request: Request) -> _bytes:
return await self.web.read_request_content(request)
[docs] def bytes_to_response(self, s: _bytes) -> Response:
return self.web.bytes_to_response(s)
[docs] def response_to_bytes(self, response: Response) -> _bytes:
return self.web.response_to_bytes(response)
[docs] def route(self, pattern: str, handler: Callable) -> Any:
self.web.route(pattern, handler)
return handler
[docs] def notfound(self, reason: str = 'Not Found', **kwargs: Any) -> Response:
# Deprecated: Use raise NotFound() instead.
return self.error(404, reason, **kwargs)
[docs] def error(self, status: int, reason: str, **kwargs: Any) -> Response:
return self.json({'error': reason, **kwargs}, status=status)
[docs]def takes_model(Model: Type[ModelT]) -> ViewDecorator:
def _decorate_view(fun: ViewHandlerFun) -> ViewHandlerFun:
@wraps(fun)
async def _inner(view: View, request: Request,
*args: Any, **kwargs: Any) -> Response:
data: bytes = await view.read_request_content(request)
obj: ModelT = Model.loads(data)
return await fun(view, request, obj, *args, **kwargs)
return _inner
return _decorate_view
[docs]def gives_model(Model: Type[ModelT]) -> ViewDecorator:
def _decorate_view(fun: ViewHandlerFun) -> ViewHandlerFun:
@wraps(fun)
async def _inner(view: View, request: Request,
*args: Any, **kwargs: Any) -> Response:
response: Any
response = await fun(view, request, *args, **kwargs)
return view.json(response)
return _inner
return _decorate_view
