Implementing error-handling solutions

Chapter 1 showcased the use of the redirect() method in rendering error pages given a status code, such as the status code 500. We will now discuss a better way of managing exceptions and status codes, including triggering error pages per status code.

Flask applications must always implement an error-handling mechanism using any of the following strategies:

• Registers a custom error function using the app’s register_error_handler() method.
• Creates an error handler using the app’s errorhandler decorator.
• Throws a custom Exception class.

Using the register_error_handler method

The declarative way to implement an error handler is to create a custom function and register it to the app’s register_error_handler() method. The custom function must have a single local parameter that will accept the injected error message from the platform. It must also return its assigned error page using the make_response...