36 lines
1.2 KiB
Python
36 lines
1.2 KiB
Python
|
from typing import Awaitable, Callable, Iterable
|
||
|
|
|
||
|
|
from aiohttp.web_middlewares import middleware
|
||
|
|
from aiohttp.web_request import Request
|
||
|
|
from aiohttp.web_response import StreamResponse
|
||
|
|
|
||
|
|
Handler = Callable[[Request], Awaitable[StreamResponse]]
|
||
|
|
Middleware = Callable[[Request, Handler], Awaitable[StreamResponse]]
|
||
|
|
|
||
|
|
|
||
|
|
def cors(allow_headers: Iterable[str]) -> Middleware:
|
||
|
|
@middleware # type: ignore[misc]
|
||
|
|
async def impl(request: Request, handler: Handler) -> StreamResponse:
|
||
|
|
is_options = request.method == "OPTIONS"
|
||
|
|
is_preflight = is_options and "Access-Control-Request-Method" in request.headers
|
||
|
|
if is_preflight:
|
||
|
|
resp = StreamResponse()
|
||
|
|
else:
|
||
|
|
resp = await handler(request)
|
||
|
|
|
||
|
|
origin = request.headers.get("Origin")
|
||
|
|
if not origin:
|
||
|
|
return resp
|
||
|
|
|
||
|
|
resp.headers["Access-Control-Allow-Origin"] = "*"
|
||
|
|
resp.headers["Access-Control-Expose-Headers"] = "*"
|
||
|
|
if is_options:
|
||
|
|
resp.headers["Access-Control-Allow-Headers"] = ", ".join(allow_headers)
|
||
|
|
resp.headers["Access-Control-Allow-Methods"] = ", ".join(
|
||
|
|
("OPTIONS", "POST")
|
||
|
|
)
|
||
|
|
|
||
|
|
return resp
|
||
|
|
|
||
|
|
return impl # type: ignore[no-any-return]
|