John Salerno wrote:
> Ok, I have a new random question for today -- feel free to ignore and
> get back to your real jobs! :)
>
> Anyway, I'm creating a GUI (yes, all part of my master plan to
> eventually have some sort of database application working) and it's
> going to involve a wx.Notebook control. I think I have two options for
> how I can do this. Within the class for the main window frame, I can say:
>
> notebook = wx.Notebook(panel) # panel is parent of the Notebook control
>
> This uses the default wx.Notebook class, and works just fine. But I was
> thinking, is it a smart idea to do this instead:
>
> class MyNotebook(wx.Notebook):
> def __init__(self, parent):
> wx.Notebook.__init__(self, parent)
>
> and then call it from the main frame as:
>
> notebook = MyNotebook(panel)
>
> This seems to allow for future expansion of the customized Notebook
> class, but at the same time I have no idea how or why I'd want to do that.
>
> So my question in general is, is it a good idea to default to an OOP
> design like my second example when you aren't even sure you will need
> it?
It of course depends on a lot of factors. Two of these factors are:
1/ given my current knowledge of the project, what are the probabilities
that I'll end up subclassing wx.Notebook ?
2/ if so, in how many places would I have to s/wx.Notebook/MyNotebook/
The second factor is certainly the most important here. Even if the
answer to 1/ is "> 50%", if there's only a couple of calls in a single
file, there's really no need to do anything by now IMHO.
As a side note, the common OO pattern for this potential problem is to
replace direct instanciation with a factory, so you just have to modify
the factory's implementation.
Now one of the nice things with Python is that it doesn't have a "new"
keyword, instead using direct calls to the class (the fact is that in
Python, classes *are* factories already). Another nice thing is that you
can easily 'alias' callables. The combination of these 2 features makes
factory pattern mostly straightforward and transparent. As someone
already pointed out, you don't need to subclass wx.Notebook - just
'alias' it to another name.
> I know it won't hurt,
Mmm... Not so sure. One could argue that "premature generalization is
the root of all evil" !-)
> and is probably smart to do sometimes,
cf above.
> but
> maybe it also just adds unnecessary code to the program.
It's not that much about the unnecessary code (which can boil down to a
single assignement), but about the unnecessary level of indirection
(which, as someone stated, is the one and only problem that cannot be
solved by adding a level of indirection !-).
--
bruno desthuilliers
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p in '[EMAIL PROTECTED]'.split('@')])"
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