Unused response_factory argument of web.UrlDispatcher.add_static/web.StaticResource

[zemlanin]

Long story short

Argument response_factory doesn't affect static responses

Expected behaviour

aiohttp should call custom class passed to aiohttp.web.UrlDispatcher.add_static()

Actual behaviour

response_factory value is ignored

Steps to reproduce

class CORSStreamResponse(web.StreamResponse):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        if 'Access-Control-Allow-Origin' not in self.headers:
            self.headers['Access-Control-Allow-Origin'] = '*'

# ...

app.router.add_static('/static', f'./static', name='static', response_factory=CORSStreamResponse)

$ curl -I http://localhost:8000/static/bundle.js
HTTP/1.1 200 OK
Content-Type: application/javascript
Last-Modified: Tue, 19 Sep 2017 10:08:45 GMT
Content-Length: 84833
Date: Mon, 25 Sep 2017 14:07:59 GMT
Server: Python/3.6 aiohttp/2.2.5

Your environment

aiohttp==2.2.5

[asvetlov]

Not sure if we need support the factory.
Initially it was exist for overriding default behavior.
After aiohttp.web.FileResponse introduction user can make own web-handler for sending custom files easy.

FileResponse is not documented though.
What we really should do is writing docs for the response.

@zemlanin @Axik what is your motivation for passing custom factory instead of using the proposed way?

[zemlanin]

@asvetlov As I wrote in "Steps to reproduce", I've wanted to add Access-Control-Allow-Origin: * header to static file responses (for development)

[asvetlov]

Did you try just setup https://github.com/aio-libs/aiohttp-cors globally for the whole app?

[zemlanin]

What do you mean by "globally for the whole app"? Something like this from aiohttp-cors's usage?

for route in list(app.router.routes()):
    cors.add(route)

If so, then this snippet results in

  File "/usr/local/lib/python3.6/dist-packages/aiohttp_cors/urldispatcher_router_adapter.py", line 331, in add_preflight_handler
    preflight_route = route.resource.add_route(
AttributeError: 'StaticResource' object has no attribute 'add_route'

[Axik]

I'm just a stranger passing by trying to help people.
Anyway we need either fix or remove response_factory argument, because right now it's not working.

[asvetlov]

response_factory dropeed by #2307
The behavior should be supported by aiohttp-cors itself.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a [new issue] for related bugs.
If you feel like there's important points made in this discussion, please include those exceprts into that [new issue].
[new issue]: https://github.com/aio-libs/aiohttp/issues/new