I've implemented this short example to try to demonstrate a simple delegation pattern. My question is. Does this look like I've understood delegation right?
class Handler:
def __init__(self, parent = None):
self.parent = parent
def Handle(self, event):
handler = 'Handle_' +event
if hasattr(self, handler):
func = getattr(self, handler)
func()
elif self.parent:
self.parent.Handle(event)
class Geo():
def __init__(self, h):
self.handler = h
def Handle(self, event):
func = getattr(self.handler, 'Handle')
func(event)
class Steve():
def __init__(self, h):
self.handler = h
def Handle(self, event):
func = getattr(self.handler, 'Handle')
func(event)
class Andy():
def Handle(self, event):
print 'Andy is handling %s' %(event)
if __name__ == '__main__':
a = Andy()
s = Steve(a)
g = Geo(s)
g.Handle('lab on fire')
That's the basic concept, yes - passing on some incoming request to another object to take care of.
One Python tip: you don't need to say:
just say:
I'm not sure what you are doing with your Handler class, it isn't used in your example.
And in Python, methods with upper-case names are very very unusual, usually a result of porting some existing API with names like that.