There are several things about this code that suggest a less-than-optimal design:
- Using a callback to magically access data in the base workspace. Accessing data in another workspace not recommended, because it makes code slow, complex, and buggy (your question demonstrates this). A much better ("better" in the sense neater, more robust, much more efficient, less buggy) solution is to pass data to the GUI and process it within the GUI itself.
- The variable name varString seems to suggest that you want to magically access variable names. Magically accessing variable names is one way that some beginners force themselves into writing slow, complex, buggy code that is hard to debug:
You would be much better off passing the data properly as input/output arguments, and processing it within the GUI.
See also your earlier question:
