[Bf-python] API refactoring considerations

[Gilbert, Joseph T.]

1) I think returning True/False is a good idea. 

2) We have always clamped input to whatever the internal range is and
have not thrown an error. In theory though, it may be better to throw an
error because the user may have expected a certain result and didn't
realize that his value got clamped. All the other methods throw
AttributeError when they receive unexpected parameters.  I think in this
case though we need to throw a ValueError because we have the correct
type of argument but it's the wrong value for the method.

-----Original Message-----
From: bf-python-bounces at projects.blender.org
[mailto:bf-python-bounces at projects.blender.org] On Behalf Of Ken Hughes
Sent: Tuesday, May 30, 2006 9:23 PM
To: Blender Foundation Python list
Subject: [Bf-python] API refactoring considerations

As I' working on the Object.c tp_getset switchover, two questions came 
up which I think would be nice to decide (a) prior to the API refactor 
and (b) hopefully before I finish working on this module:***

(1) We decided around the 2.40 release that attribute setters should be 
as forgiving as possible, for example using PyObject_IsTrue() to 
evaluate things boolean.  Well, since True/False are coerced internally 
to integers when you say things like "if True==1:" and "y=True+1", maybe

it's time to start having attribute getters returning boolean when they 
really are booleans?
(2) I was about to start range checking attribute setters.  My 
rule-of-thumb (or maybe it really is the rule) is that if the UI clamps 
the input (for something a slider) then I use EXPP_ClampX(), otherwise I

check for explicit inputs (like for a menu or bitfield) and throw an 
exception if the value lies outside the range.  After something Stephen 
said a few weeks back about armature.setName() -- which if the name is 
already used creates a different name but doesn't throw an exception -- 
I realize EXPP_ClampX() is a similar situation.  So should the API clamp

inputs or should it throw exceptions in this case?

Ken

***and by the way, 
http://mediawiki.blender.org/index.php/BlenderDev/Bitfields still would 
appreciate your comments.
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