t.i.d.inlineCallbacks(f) : function documentation

WARNING: this function will not work in Python 2.4 and earlier!

inlineCallbacks helps you write Deferred-using code that looks like a regular sequential function. This function uses features of Python 2.5 generators. If you need to be compatible with Python 2.4 or before, use the deferredGenerator function instead, which accomplishes the same thing, but with somewhat more boilerplate. For example:

   @inlineCallBacks
   def thingummy():
       thing = yield makeSomeRequestResultingInDeferred()
       print thing #the result! hoorj!

When you call anything that results in a Deferred, you can simply yield it; your generator will automatically be resumed when the Deferred's result is available. The generator will be sent the result of the Deferred with the 'send' method on generators, or if the result was a failure, 'throw'.

Your inlineCallbacks-enabled generator will return a Deferred object, which will result in the return value of the generator (or will fail with a failure object if your generator raises an unhandled exception). Note that you can't use return result to return a value; use returnValue(result) instead. Falling off the end of the generator, or simply using return will cause the Deferred to have a result of None.

The Deferred returned from your deferred generator may errback if your generator raised an exception:

   @inlineCallbacks
   def thingummy():
       thing = yield makeSomeRequestResultingInDeferred()
       if thing == 'I love Twisted':
           # will become the result of the Deferred
           returnValue('TWISTED IS GREAT!')
       else:
           # will trigger an errback
           raise Exception('DESTROY ALL LIFE')