chain method
Returns a strongly-typed chained callback that calls through to the two provided callbacks, a
and b
, in order.
Useful for executing multiple callbacks where only a single callback is accepted.
Returns false
if one or more of the provided callbacks returns false
.
Gracefully handles when a
and/or b
are null, always returning a callable function.
Implementation
@override
Callback0Arg chain(Callback0Arg? a, Callback0Arg? b) {
if (a == null) return b ?? noop;
if (b == null) return a;
dynamic chained() {
var aDidReturnFalse = a() == false;
var bDidReturnFalse = b() == false;
if (aDidReturnFalse || bDidReturnFalse) return false;
}
return chained;
}