Exception handling

While it may be a cold day in hell before we see any TRY..CATCH constructs in pure C/AL, we are all far more lucky when it comes to .NET interoperability. In this blog post I’ll (re)present the same concept I demonstrated during NAV TechDays 2013 last year in Antwerp, because I am quite sure this nifty little trick got lost under piles of other posts on this blog.

Did I CATCH your attention yet? At least I did TRY. Now that I have completed my series on exception handling in C/AL , a very valid question pops up: why don’t we have try..catch syntactical constructs in C/AL, the way we have it in other programming languages?

Good. At this point we know everything about exception types, what they are, how to obtain them, how to compare them (at least directly). All of these have suddenly become relevant now that we have GETLASTERROROBJECT function in NAV 2015. But an old friend is still around, the GETLASTERRORCODE function, what about it?

To continue my series about exception handling in NAV, this time I’ll discuss how to gain insight into exceptions in NAV. As I mentioned already, the GETLASTERROROBJECT function gives you an instance of System.Exception, actually of a class descending from it, which allows you to get more information about the context of the error that has just happened.

In my last post I have introduced the GETLASTERROROBJECT function that returns you the instance of the System.Exception class, representing the actual exception that has happened. To properly handle exceptions in an unambiguous way, you must use the exception type, not its name, so it is important to get the actual System.Type representing the exception type.

You may love C/AL as a language, but there is an area in it that you must just hate. It’s the error handling. Plainly put, and being actually quite positive about it, in NAV, error handling just sucks. If an error happens, it happens.