[Twisted-Python] Making inlineCallback return a generator rather than a Deferred

Andrew Francis andrewfr_ice at yahoo.com
Sat Jan 26 15:21:45 EST 2008

Hello Folks:

As I previously mentioned, I have the following called
from a PyAMF method:

def echo(self, x):
    result = yield client.getPage("http://localhost")

because of the yield, I cannot use

    return result

In a bout of wishful thinking, I tried the following:

def __echo__(self, x):
    result = yield client.getPage("http://localhost")
    yield result

def echo(self, x):
    return self.__echo__(x).next()

This raises an AttributeError, the deferred does not
have an attribute next() (this is because the deferred
is well, a deferred)

Again, perhaps I am missing something obvious. Or
perhaps this scenario was not anticipated and syntax
is getting in the way. However I think the following
would be useful in these situations

def echo(self, x)
    def __echo__(x):
        result = yield client.getPage("...")
        yield result

    the method waits until there is a result
    return __echo__(x).next()

and the wrapper (i.e., PyAMF, xmlrpc, etc) is happy.

I started to look at defer.inlineCallbacks and its
associated methods, such as and _inlineCallbacks,
unwindGenerator, and mergeFunctionMetadata. 

I would like to know if it would make sense to just
return a generator and have it behave the way I want.
If so, what exactly do I have to do in some variation
of _inlineCallbacks to make this so?


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