[Web-SIG] A 'shutdown' function in WSGI

[Graham Dumpleton]

On 21 February 2012 20:26, Simon Sapin <simon.sapin at exyr.org> wrote:
> Le 21/02/2012 09:23, Tarek Ziadé a écrit :
>
>>    Instead of having to provide two or three objects separately to a
>>    server, how about making the callbacks attributes of the application
>>    callable?
>>
>>
>> can you show us an example ?
>
>
> Proposal:
>
> Function-based:
>
>    def startup():
>        return open_resource(something)
>
>    def shutdown(resource):
>        resource.close()
>
>    def application(environ, start_response):
>        # ...
>        return response_body
>
>    application.startup = startup
>    application.shutdown = shutdown
>
> Class-based:
>
>    class App(object):
>        def startup(self):
>            return open_resource(something)
>
>        def shutdown(self, resource):
>            resource.close()
>
>        def __call__(self, environ, start_response):
>            # ...
>            return response_body
>
>    application = App()
>
> The return value of startup() can be any python object and is opaque to the
> server. It is passed as-is to shutdown()
>
> startup() could take more parameters. Maybe the application (though can we
> already have it as self for class-based or in a closure for function-based)

You do realise you are just reinventing context managers?

With this 'application' do requests.

But then it was sort of suggested that was a bit too radical idea when
I have mentioned viewing it that way before. :-(

Graham