RegisterCallbackHandler typedef

ZoneCallback<R> RegisterCallbackHandler <R>(
  1. Zone self,
  2. ZoneDelegate parent,
  3. Zone zone,
  4. R f( )
)

The type of a custom Zone.registerCallback 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 Zone.registerCallback of zone.

The handler should return either the function f or another function replacing f, typically by wrapping f in a function which does something extra before and after invoking f

Implementation

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

© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dart.dev/stable/2.13.0/dart-async/RegisterCallbackHandler.html