Frank Millman wrote:
"MRAB" <pyt...@mrabarnett.plus.com> wrote in message
news:mailman.444.1251290454.2854.python-l...@python.org...
An alternative is:
class MyClass(object):
... def on_message_received(self, msg):
... try:
... getattr(self, "method_%d" % msg)()
... except AttributeError:
... raise Exception("Unknown message")
... def method_0(self):
... print 'in method_0'
... def method_1(self):
... print 'in method_1'
...
my_obj = MyClass()
my_obj.on_message_received(0)
in method_0
my_obj.on_message_received(1)
in method_1
my_obj.on_message_received(2)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "<stdin>", line 6, in on_message_received
Exception: Unknown message
I like the idea. Unfortunately my real-world situation is a little more
complex than my simple example implied.
This is a more typical example -
(EVT_GETLOGIN
,EVT_LOGOUT
,EVT_GETMENUOPT
,EVT_GOTFOCUS
,EVT_LOSTFOCUS
,EVT_BUTTONCLICKED
,EVT_CHECKBOX
...
) = xrange(28)
method_dict = {}
method_dict[EVT_GETLOGIN] = onGetLogin
method_dict[EVT_LOGOUT] = onLogout
method_dict[EVT_GETMENUOPT] = onGetMenuOpt
method_dict[EVT_GOTFOCUS] = onGotFocus
method_dict[EVT_LOSTFOCUS] = onLostFocus
method_dict[EVT_BUTTONCLICKED] = onButtonClicked
method_dict[EVT_CHECKBOX] = onCheckBox
You can probably figure out from my method names what I am doing here - the
messages are sent by a thin client (wxPython), and processed by a server.I
am anticipating some "don't do that" responses, but I like the concept, and
so far it is very fast and responsive, so I will pursue it for now.
Thanks for the input.
Frank
Any time I see multiple lists like that which have to stay in synch, I
think code-smell.
Why not let the EVT's be passed as strings, and avoid the whole mapping
to integers and mapping back detail? And name the methods involved in a
way that you can directly translate the string to the method name?
Barring that, make a single "structure" which lists the event names and
method names in matched pairs, and derive whatever lists and
dictionaries you actually need from that one structure. And that
structure should be shared between client and server code, perhaps as a
text file that they both parse. Or as a stream that's passed from one
to the other during startup. That way, consistency between them can be
regulated (with version string in the file, for example)
DaveA
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