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Class: ViewPoint Twisted-0.17.4/twisted/spread/flavors.py

I act as an indirect reference to an object accessed through a Perspective.

Simply put, I combine an object with a perspective so that when a peer calls methods on the object I refer to, the method will be invoked with that perspective as a first argument, so that it can know who is calling it.

While Viewable objects will be converted to ViewPoints by default when they are returned from or sent as arguments to a remote method, any object may be manually proxied as well. (XXX: Now that this class is no longer named Proxy, this is the only occourance of the term proxied in this docstring, and may be unclear.)

This can be useful when dealing with Perspectives, Copyables, and Cacheables. It is legal to implement a method as such on a perspective:

     | def perspective_getViewPointForOther(self, name):
     |     defr = self.service.getPerspectiveRequest(name)
     |     defr.addCallbacks(lambda x, self=self: ViewPoint(self, x), log.msg)
     |     return defr

This will allow you to have references to Perspective objects in two different ways. One is through the initial attach call -- each peer will have a RemoteReference to their perspective directly. The other is through this method; each peer can get a RemoteReference to all other perspectives in the service; but that RemoteReference will be to a ViewPoint, not directly to the object.

The practical offshoot of this is that you can implement 2 varieties of remotely callable methods on this Perspective; view_xxx and perspective_xxx. view_xxx methods will follow the rules for ViewPoint methods (see ViewPoint.remoteMessageReceived), and perspective_xxx methods will follow the rules for Perspective methods.

Base Classes   
Referenceable
Methods   
__init__
processUniqueID
remoteMessageReceived
  __init__ 
__init__ (
        self,
        perspective,
        object,
        )

Initialize me with a Perspective and an Object.

  processUniqueID 
processUniqueID ( self )

Return an ID unique to a proxy for this perspective+object combination.

  remoteMessageReceived 
remoteMessageReceived (
        self,
        broker,
        message,
        args,
        kw,
        )

A remote message has been received. Dispatch it appropriately.

The default implementation is to dispatch to a method called view_messagename to my Object and call it on my object with the same arguments, modified by inserting my Perspective as the first argument.


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This document was automatically generated on Sat Apr 20 01:31:32 2002 by HappyDoc version 2.0