Wondering if anyone can explain the difference between errors and exception errors, or, more specifically, when one should use addError(errorMsg) instead of addError(exceptionError)?
The documentation is a little obtuse to me. I think it also is accidentally explaining the addError(errorMsg) method twice right now, which I'm finding a little confusing.
Don't they both just show an error in the application interface? In my particular case, I don't actually need anything to pop up in the UI, I just need to surface an error so that DataLoader knows why records fail if they fail. Not sure which to use.
Best Answer
If you're using try-catch, consider using addError(Exception) if you want to write smaller code[citation needed], and if you're not, use addError(String). In my experience, properly bulkified code will typically use addError(String).
The addError(Exception) method is typically used when you're writing atomic updates, usually within a Visualforce page, and the addError(String) method is more likely to be used in a trigger so it is properly bulkified (e.g. some records can succeed while others fail).
Both will result in an error being reported to the upper-level API, which might be a user saving a record, a Visualforce page, or an API-enabled tool like the Apex Data Loader. Both have the same general effect (the Data Loader will get an error in the errors*.csv file).