On Fri, Aug 13, 2010 at 5:01 AM, Mark Summerfield <[email protected]> wrote:
> On Thu, 12 Aug 2010 17:37:12 -0300
> Marcelo Lira <[email protected]> wrote:
>> According to PSEP 101[1] a constructor for QObject and derived classes
>> should be able to set Qt properties through named arguments.
>> In practical terms to set the Qt property "objectName" to "foobar" one
>> should do:
>>
>> obj = QObject(objectName='foobar')
>>
>> This can be done in a more verbose way:
>>
>> obj = QObject()
>> obj.setProperty('objectName', 'foobar')
>>
>> You can set dynamic properties, i.e. not previously declared on the
>> QObject derived object:
>>
>> obj = QObject()
>> obj.setProperty('myNumber', 123)
>
> [snip]
>
> I agree with Matti that this should be a separate PEP if you plan to
> pursue it.
>
> As I understand it you want to allow:
>
> obj = QObject(my_new_property="Hello")
>
> on the basis that the user can do this at any time:
>
> obj.setProperty("my_new_property", "Hello")
>
> I am opposed to this.
>
> At the moment only existing properties can be set in the constructor,
> which means that typos and other errors result in an exception which I
> think is good.
>
> This means that if someone wants to add a new property they must use
> QObject.setProperty(), in other words they must do so explicitly, which
> I think is a good thing.
>
> -1
>
Until yesterday I was agreeing with this change but after thinking
better, I believe that leaving the constructor accepting only already
existing properties would be cleaner/better. Somewhat like this pure
python example:
class Bacon:
def __init__(self, myprop=0, myotherprop='eggs'):
self.myprop = myprop
self.myotherprop = myotherprop
And to set the dynamic ones, use the "setattr" function. Setting
dynamic ones in the constructor would endup using **kwargs magic.
So, -0.5.
--
Lauro Moura
INdT - Instituto Nokia de Tecnologia
_______________________________________________
PySide mailing list
[email protected]
http://lists.openbossa.org/listinfo/pyside
