Global exception handling in a GUI class

Hi,

I have a class that represents a GUI window and want to display any kind of exception that occurs in any class method as a errordlg (as console output ist not useful when using a gui).

• Is there a convenient way to redirect all exception-message-strings to the function errordlg()?
• This should especially include all errors that occur within any class method (like a call to obj.methodXY())
• It is desireable to catch also other errors (like wrong use of obj(..))

I have already tried overloading B=subsref(A,S), but this causes vast problems when methods with/without input-/output-arguments are called.

[Daniel Shub]

Have you tried overloading error?

Answer 1

[Sean de Wolski]

I don't think there is a way to redirect from standard error to error dialog. You'll have to catch the MException and then throw the error dialog from there. This could be packaged as a function to make it reusable.

[Gregor]

Yes I have assumed that there is no general function or the like to do this.

Of course I could place try-catch-statements in every single class method to redirect the error to an error dialog. But I want to avoid to do this for every method.

I would like to have something similar to the approach in the following piece of code: the subsref() method does exactly the same as the builtin-subsref method but for redirecting every exception to an error dialog:

class classX < handle
methods
 function method1(obj, arg1);
 function out1 = method2(obj);
   function varargout = subsref(obj, S)
   try
       varargout = builtin('subsref', obj, S);                
   catch ex
       errordlg(ex.message, ex.identifier);
   end   function obj = classX()
   % constructor code...
   endend
end
In this code, the subsref method doesn't perform well with different types of methods.

[Sean de Wolski]

I guess I don't understand how subsref would be called from a user using the figure/GUI/app.

Wouldn't whatever the user is doing be safeguarded against at that level? How are they going to use subsref?