Masonx::interp::withcallbacks subclasses html::mason::interp in order to provide a mason callback system built on params::callbackrequest. callbacks may be either code references provided to the new() constructor, or methods defined in subclasses of params::callback. callbacks are triggered either for every request or by specially named keys in the mason request arguments, and all callbacks are executed at the beginning of a request, just before mason creates and executes the request component stack.

this module brings support for a sort of plugin architecture based on params::callbackrequest to mason. mason then executes code before executing any components. this approach allows you to carry out logical processing of data submitted from a form, to affect the contents of the mason request arguments (and thus the %args hash in components), and even to redirect or abort the request before mason handles it.