Custom error handling in Google Sheets functions: How to display user-friendly messages?

Other Questions Google Sheets
1

I’m trying to improve the error handling in my Google Sheets custom functions. When users input incorrect data, I want to show them helpful error messages without confusing technical details.

Right now, if I throw an exception in my function, it shows #ERROR! in the cell, which is fine. The pop-up displays my custom message, but it also adds the line number where the error occurred. This extra info might confuse users who don’t need to know about the code.

Is there a way to show only my custom error message without the line number? I want to give clear feedback to users about what went wrong, just like built-in functions do (e.g., SQRT(-1) shows #NUM! with a helpful explanation).

Has anyone figured out how to create these user-friendly error messages in Google Sheets custom functions? Any tips or workarounds would be really appreciated!

2

I’ve dealt with this exact issue in my custom functions. One workaround I found is to return a string that starts with ‘#ERROR!’ followed by your custom message. For example:

return ‘#ERROR! Please enter a positive number’;

This approach mimics the built-in error format while allowing you to provide a tailored message. The cell will display ‘#ERROR!’, and when users hover over it, they’ll see your specific instructions without any confusing line numbers.

Just remember that this method means your function is technically returning a string, not an actual error object. In most cases, this works fine, but be aware it might affect error handling elsewhere in your spreadsheet if you’re relying on true error detection.

I’ve been using this method for months now, and it’s made my spreadsheets much more user-friendly. Hope this helps!

3

While Grace_31Dance’s suggestion is clever, there’s another approach worth considering. You can use the SpreadsheetApp.getUi() method to display a custom modal dialog when an error occurs. This allows for more detailed explanations without cluttering the cell.

Here’s a basic implementation:

  1. In your function, catch errors and call a separate error handling function.
  2. The error handler uses SpreadsheetApp.getUi().alert() to show a custom message.
  3. Return a simple ‘#ERROR!’ string from your main function.

This method keeps cells clean, provides detailed user guidance, and maintains proper error object behavior. It’s particularly useful for complex functions where users might need more explanation than a single line can provide.

Just be mindful that this approach requires authorization, so it’s best suited for spreadsheets where users already trust your script.

4

hey, you could try using the throw statement with a custom error object. something like:

throw new Error('Please enter a valid date');

this way, you get the ‘#ERROR!’ in the cell, but only your message shows in the popup. it’s worked great for me in keeping things user-friendly!