[Twisted-web] Problem with twisted web and adbapi

[Phil Mayers]

> 
> Request did not return a string
> Request:
> <GET / HTTP/1.1>
> 
> 
> Resource:
> <__main__.Simple instance at 0x1208878>
> 
> 
> Value:
> <Deferred at 0x124cfa8>
> 
> 
> 
> 
> Later when the _getUserList() returns the Defered object calles the
> cb() function and i get a printout with the wanted result.
> 
> 
> So I think my problem is that I whant to *wait* for the result from
> the db query before the render_GET() returns.

No, you definitely don't wait - that defeats the entire point of using
an event-driven system.

See:

http://twistedmatrix.com/documents/current/api/twisted.web.resource.IResource.html

Basically:

def render_GET(self, request):
    def cb(data):
        request.write(data)
    # note, we add our callback to the deferred then discard it
    self.opt.dbpool.runInteraction(blah).addCallback(cb)
    # we *return* a special value
    return server.NOT_DONE_YET


HTH

>