void initState()
{
base.initState();
_snapshot = AsyncSnapshot <T> .withData(ConnectionState.none, widget.initialData);
_subscribe();
}
void _subscribe()
{
if (widget.future != null)
{
object callbackIdentity = new object();
_activeCallbackIdentity = callbackIdentity;
widget.future.then((object dataIn) => {
var data = (T)dataIn;
if (_activeCallbackIdentity == callbackIdentity)
{
setState(() => { _snapshot = AsyncSnapshot <T> .withData(ConnectionState.done, data); });
}
}, onError: (Exception error) => {
if (_activeCallbackIdentity == callbackIdentity)
{
setState(() => { _snapshot = AsyncSnapshot <T> .withError(ConnectionState.done, error); });
}
return(FutureOr.nil);
});
_snapshot = _snapshot.inState(ConnectionState.waiting);
}
}
AsyncSnapshot <T> afterData(AsyncSnapshot <T> current, T data)
{
return(AsyncSnapshot <T> .withData(ConnectionState.active, data));
}
AsyncSnapshot <T> initial() => AsyncSnapshot <T> .withData(ConnectionState.none, initialData);