Handling exceptions

Let’s consider the problem of how to handle exceptions? Assume we have already chosen to go beyond the “method” of simply ignoring them by placing a Set Error Capture[ On ] step at the beginning of a script. Shouldn't we then just write code like this?

Well, I think that though the code above is correct, it still has a problem: it mixes the exception part with the main functionality. It's difficult to follow such a code. Imagine there's three error-checking conditions in a script and you're reading it after a while; you'll have to open three script steps and read their formulas to understand what's going on.

Though you cannot avoid the mix, it worth trying to clearly separate the part that handles exceptions from the rest of your code. After all, exception handling requires very limited functionality: you need to throw an exception, watch for it, and handle it somehow.

I'm going to describe a system I use. The description is fairly long, but actually the system is very simple and takes a couple of fields, a couple of scripts and a handful of very simple custom functions.