[Insight-users] Python wrapping + exceptions

[Luis Ibanez]

Hi Charl,

Your observation is correct,
ITK is throwing a C++ exception that is not being catched.

The ideal fix would be to figure out a mechanism for catching
C++ exceptions and translate them into Python exceptions.

Your suggestion is a nice option too, since at least the
error message will be available before the program terminates.
The challenge would be to implement this in a way that is
not too invasive on the C++ side.

If you see a viable way of implementing this, we will be
happy to incorporate it on the toolkit.


Thanks


   Luis


---------------------

Charl P. Botha wrote:
> Dear list,
> 
> In Insight, error conditions are often handled by calling 
> ITKExceptionMacro which on its part throws a C++ exception.  This is all 
> fine and well for C++ applications, where these can be neatly caught.
> 
> In the Python wrapping however, there is no catch for the exception, so 
> the whole wrapped ITK application is unceremoniously terminated.  Am I 
> missing something?
> 
> If not, perhaps an itk::Object static variable that changes the 
> ITKException behaviour to an that of onITKErrorMacro (still to be 
> created, but it looks a lot like ITKWarningMacro) would be appropriate. 
>  ITKErrorMacro would invoke an event that would trigger the appropriate 
> observers or output an error message if no observers have been 
> registered.  Yes, this is almost exactly like VTKErrorMacro. :)
> 
> Are there better ways to solve this?  If not, I can start making a patch 
> to implement this.
> 
> Thanks,
> Charl
>