Pass parameter to initState - dart

Question

Look at this code - widget to fetch data and display on list:
class _MyEventsFragmentState extends State <MyEventsFragment>{
var events;
#override
initState(){
super.initState();
events = fetchEvents(true);
}
#override
Widget build(BuildContext context) {
return new Center(
child: FutureBuilder<EventsResponse>(
future: events,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
if (snapshot.hasError) {
helpers.logout(context, Strings.msg_session_expired);
return CircularProgressIndicator();
}
return new Container(color: Colors.white,
child: new ListControl().build(snapshot));
}
return CircularProgressIndicator();
},
)
);
}
}
fetchEvent method has parameter to indicate which events I need to fetch. If set to true, - my events, if set to false - all events returned. Above code loads my events and fetchEvents is called inside initState override to avoid unnecesary data reloading.
To fetch all events I defined another class:
class EventsFragment extends StatefulWidget {
#override
_EventsFragmentState createState() => new _EventsFragmentState();
}
class _EventsFragmentState extends State <EventsFragment>{
var events;
#override
initState(){
super.initState();
events = fetchEvents(false);
}
#override
Widget build(BuildContext context) {
return new Center(
child: FutureBuilder<EventsResponse>(
future: events,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
if (snapshot.hasError) {
helpers.logout(context, Strings.msg_session_expired);
return CircularProgressIndicator();
}
return new Container(color: Colors.white,
child: new ListControl().build(snapshot));
}
return CircularProgressIndicator();
},
)
);
}
}
But this is very dumb solution, because code is almost the same. So I tried to pass boolean value to indicate which events to load, something like that:
#override
initState(){
super.initState();
events = fetchEvents(isMyEvents);
}
isMyEvents should be got from EventsFragment constructor. However, it won't be accesible inside initState. Ho to pass it properly? I could access it inside build override, but not inside initState. How to pass it properly and make sure it will be refreshed every time widget instance is created?
[edit]
So this how I solved my problem (it seems to be fine):
class EventsFragment extends StatefulWidget {
const EventsFragment({Key key, this.isMyEvent}) : super(key: key);
final bool isMyEvent;
#override
_EventsFragmentState createState() => new _EventsFragmentState();
}
class _EventsFragmentState extends State <EventsFragment>{
var events;
#override
initState(){
super.initState();
events = fetchEvents(widget.isMyEvent);
}
#override
void didUpdateWidget(EventsFragment oldWidget) {
if(oldWidget.isMyEvent != widget.isMyEvent)
events = fetchEvents(widget.isMyEvent);
super.didUpdateWidget(oldWidget);
}
#override
Widget build(BuildContext context) {
return new Center(
child: FutureBuilder<EventsResponse>(
future: events,
builder: (context, snapshot) {
if (snapshot.connectionState == ConnectionState.done) {
if (snapshot.hasError) {
helpers.logout(context, Strings.msg_session_expired);
return CircularProgressIndicator();
}
return new Container(color: Colors.white,
child: new ListControl().build(snapshot));
}
return CircularProgressIndicator();
},
)
);
}
}

Answer 1

Pass such parameter to the StatefulWidget subclass, and use that field instead
class Foo extends StatefulWidget {
const Foo({Key key, this.isMyEvent}) : super(key: key);
final bool isMyEvent;
#override
_FooState createState() => _FooState();
}
class _FooState extends State<Foo> {
#override
void initState() {
super.initState();
print(widget.isMyEvent);
}
#override
Widget build(BuildContext context) {
return Container(
);
}
}