Feature: #107581 - Improve handling of FinisherException
See forge#107581
Description
\Finisher instances thrown during
form processing are now caught within their respective finisher. Instead of
resulting in a generic 503 error page, the exception is logged, and a
user-friendly error message is displayed to the user, indicating that the form
could not be submitted successfully.
The error message can be customized for each finisher using the new
error option. Additionally, the newly introduced Error
template can be overridden and customized.
Impact
Users no longer see a 503 error page if a FinisherException occurs. Instead, they receive a clear, user-friendly message in the form frontend. All FinisherExceptions are logged for further analysis and debugging.
This change improves the user experience and makes error handling in forms more flexible and transparent.