instance creatiion as an "event"
Arthur
ajsiegel at optonline.net
Tue Apr 22 10:54:17 EDT 2003
I had written -
>Standalone, yes. But, unless I'm missing something, the effects in an
>inheritance chain is different. If I inherit from TestPoint, and need to
>call TestPoint.__init__ in the Point_Child.__init__ to pick up
initilization
>routines common to the chain, I will now unavoidably be calling TestPoint's
>redraw method before I call Point_Child's.
So I'm thinking I should perhaps go back to a fundamentally different
scheme. Instead of factory functions calling classes based on argument
composition - and therefore lots of classes and attendant inheritance
issues, there should be master classes with alternative redraw methods that
are selected in __init__ on the basis of the argument composition:
In effect:
class Point:
def __init__(self,*args):
if args are 3 planes:
self.redraw = self.redraw_from_planes
elif args are 2 lines:
self.redraw = self.redraw_from_lines
...
self.redraw()
I had experimented with this at one point and found it workable. But went
to a factory function scheme, probably for no better reason then I thought
it was a more standard approach to the general issue I faced. Serves me
right (if I am now right).
Art
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