The function that handles the request, read once: the last function
of controllers, or the controller method that a
ControllerAction (Route.get<C>(path, (C c) => c.index)) or a
(C c) => c.index function picks. The controller comes from the
container. Null when the route has no controller function.
How to call the controller (the last function of controllers),
read once. Null when the route has no controller function.
Throws a StateError when a parameter type is not known.
only match param when its text matches regex, see Route.where.
A leading ^ and a trailing $ are dropped: the regex must match
the whole param text anyway, and inside the route regex they would
never match.
The Route.where regex of param as a full match (^(?:regex)$),
built once. Null when param has no where. The router checks the
param with it again after % decoding, so %2F can not sneak a /
past a rule like [^/]+.