[Twisted-Python] Question about Using Deferreds in ServerProtocol request Handler

[Andrew Francis]

Hi Folks:

Much of what I do with Stackless involves making calls
from server requests that in turn, make Twisted calls
that return a deferred.

i.e.,

class MyRequestHandler(http.Request):
    
    """
    let us create a tasklet to do work in the request
handler
    and allow the Reactor to continue
    """
    def process(self):
        t = stackless.tasklet(self.doWork)()
        
    def doWork(self):
        message = 
MyRequestHandler.processor.getPage("")      
        self.write(message)
        self.finish()
        return

I have been able to do the same thing with an
inlineCallback

class MyRequestHandler(http.Request):
    
    @defer.inlineCallbacks
    def process(self):
        try:
            result = yield
client.getPage("http://www.google.com")
        except Exception, err:
            log.err(err, "process getPage call
failed")
        else:
            self.setHeader('Content-Type',
'text/html') 
            self.write(result)
            self.finish()

(although this works, the technique is not general for
all protocols)

However, how is this done with just deferreds and
callbacks without Stackless or inlineCallbacks?

Cheers,
Andrew
 



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