void initState()
{
base.initState();
_snapshot = AsyncSnapshot <T> .withData(ConnectionState.none, widget.initialData);
_subscribe();
}
void didUpdateWidget(StatefulWidget statefulWidget)
{
var oldWidget = statefulWidget as FutureBuilder <T>;
if (oldWidget == null)
{
return;
}
base.didUpdateWidget(oldWidget);
if (oldWidget.future != widget.future)
{
if (_activeCallbackIdentity != null)
{
_unsubscribe();
_snapshot = _snapshot.inState(ConnectionState.none);
}
_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> afterDisconnected(AsyncSnapshot <T> current) => current.inState(ConnectionState.none);
Widget build(BuildContext context, AsyncSnapshot <T> currentSummary) => builder(context, currentSummary);
AsyncSnapshot <T> afterDone(AsyncSnapshot <T> current) => current.inState(ConnectionState.done);
AsyncSnapshot <T> afterError(AsyncSnapshot <T> current, object error)
{
return(AsyncSnapshot <T> .withError(ConnectionState.active, error));
}
AsyncSnapshot <T> afterData(AsyncSnapshot <T> current, T data)
{
return(AsyncSnapshot <T> .withData(ConnectionState.active, data));
}
AsyncSnapshot <T> afterConnected(AsyncSnapshot <T> current) => current.inState(ConnectionState.waiting);
AsyncSnapshot <T> initial() => AsyncSnapshot <T> .withData(ConnectionState.none, initialData);
