RunHandler typedef

RunHandler = R Function<R>(Zone self, ZoneDelegate parent, Zone zone, R f())

The type of a custom implementation function.

Receives the Zone that the handler was registered on as self, a delegate forwarding to the handlers of self's parent zone as parent, and the current zone where the error was uncaught as zone, which will have self as a parent zone.

The function f is the function which was passed to the of zone.

The default behavior of is to call f in the current zone, zone. A custom handler can do things before, after or instead of calling f.

The function must only access zone-related functionality through self, parent or zone. It should not depend on the current zone (Zone.current).


typedef RunHandler = R Function<R>(
    Zone self, ZoneDelegate parent, Zone zone, R Function() f);