Re: [Pythoncard-users] possible to script component names?

[Andy T. <an...@ha...>]

Alex Tweedly wrote:
> Alec Bennett wrote:
>> This is a hard one to explain, but here goes. I'd like to be able to
>> script component names in my PythonCard layout.
>>
>> For example, instead of saying something like:
>>
>> self.components.button4.file = "some_picture.jpg"
>>
>> I'd like to be able to do something like:
>>
>> button_number = 4
>> button = 'self.components.button" + `button_number` + ".file =
>> "some_picture.jpg"'
>>
>> Currently I'm burying everything in way too many if statements, which
>> is always a sign I'm doing things sloppily. If I could write a
>> function that, for example, redraws only a specific button, my code
>> would get much neater. But without being able to script or concatenate
>> the component name, I can't think of a way to do that.
>>
>> Is such a thing possible? Or is there some clever way to achieve the same thing?
> As Ed says, you could use Python's  'exec'  - but that always feels a 
> bit like cheating to me :-)
> 
> In Pythoncard, you can refer to components as either
>    self.components.button4
> or
>    self.components["button4"]
> 
> so I'd do something like
> 
>     button_name = "button%d" % button_number
>     self.components[button_name].file = "something.jpg"
> 
> 
> 
> 
> -- 
> 
> Alex Tweedly      mailto:al...@tw...      www.tweedly.net
> 

And you should be able to check that the object exists before 
referencing it by using hasattr, e.g. (not tested so apologies for 
syntax errors);

 >>> button_name = 'button' + passed_in_value
 >>> if hasattr(self.components, button_name):
...     self.components[button_name] = 'something.jpg'

For a case study of how to write code without referring to widgets by 
name take a look at the dbBrowser sample application. That creates and 
modifies components at run time.

Regards,
Andy
-- 
--------------------------------------------------------------------------------
 From the desk of Andrew J Todd esq - http://www.halfcooked.com/