How to await or rebuild Consumer when data is loaded - flutter

Question

How do I reload Consumer when data is loaded or await for data to load. I am using Future Provider and everything is rebuilding itself when data is loaded (currentPosition Fetched) and using circularProgress() while waiting. But consumer is not rebuilding itself aslo can't use await with consumer package. When I save the code while debugging when it hot reload everything is okay but that's nit a solutiion. I want the consumer auto reload when data is fetched. I am fetching the data to make markers on google_Maps_Flutter
body: (currentPosition != null)
? Consumer<List<Bar>>(builder: (_, places, child) {
List.generate(places.length, (index) async {
print(places.length);
print(index);
print(imageUrl(places[index].photoRef));
List<String> wordList = places[index].name.split(" ");
bitmapIcon = await customBitmapDescriptor(
imageUrl: imageUrl(places[index].photoRef),
title: wordList[0],
);
markers = markerService.getBarMarkers(
places,
markerIcon: this.bitmapIcon,
);
print(markers.isEmpty);
});

Answer 1

Use setState((){}); to rebuild when data is loaded. Add setState((){}); where you want to rebuild e.g. if you want to reload when data is loaded in bitmapIcon then add
bitmapIcon = await convertImageFileToCustomBitmapDescriptor(
imageUrl: imageUrl(places[index].photoRef),
title: wordList[0],
).then((value) {
setState(() {});
});
And if you want to reload when data is loaded in marker then use
setState(() {
markers = markerService.getBarMarkers(
places,
markerIcon: this.bitmapIcon,
);
});
First Scenario
body: (currentPosition != null)
? Consumer<List<Bar>>(builder: (_, places, child) {
List.generate(places.length, (index) async {
print(places.length);
print(index);
print(imageUrl(places[index].photoRef));
List<String> wordList = places[index].name.split(" ");
bitmapIcon =await convertImageFileToCustomBitmapDescriptor(
imageUrl: imageUrl(places[index].photoRef),
title: wordList[0],
).then((value) {
setState(() {});
});
markers = markerService.getBarMarkers(
places,
markerIcon: this.bitmapIcon,
);
print(markers.isEmpty);
});
Second Scenario
body: (currentPosition != null)
? Consumer<List<Bar>>(builder: (_, places, child) {
List.generate(places.length, (index) async {
print(places.length);
print(index);
print(imageUrl(places[index].photoRef));
List<String> wordList = places[index].name.split(" ");
bitmapIcon = await convertImageFileToCustomBitmapDescriptor(
imageUrl: imageUrl(places[index].photoRef),
title: wordList[0],
);
if(!isSet){
setState(() {
markers = markerService.getBarMarkers(
places,
markerIcon: this.bitmapIcon,
);
});
}
print(markers.isEmpty);
});
Thumbs up if this solution helped

Answer 2

Using notifyListener() you can change the state of a consumer.
Below is a sample code. If You need more let me know.
Consumer<DataProviderClass>(
builder: (context, portfolioProvider, _) {
print("state changed");
return RaisedButton(
child: Text("Press"),
onPressed : () =>
Provider.of<DataProviderClass(context).fetchData(),
);
}
);
class DataProviderClass with ChangeNotifier{
fetchData(){
notifyListener();
}
}