Dart - processing RxCommand result before send it to RxLoader - flutter

Question

I'm writing a Flutter app and I decided to use RxDart to pass my data and events along the managers, services and UI.
Basically I have a service which fetches data from a web service and returns it. Let's assume it returns a List of a model called ExploreEntity.
class ExploreMockService extends ExploreServiceStruct {
final String response = /** a sample json **/;
#override
Future<List<ExploreEntity>> loadExploreData(PaginationInput input) async {
await Future.delayed(new Duration(seconds: 2));
return List<ExploreEntity>.from(jsonDecode(response));
}
}
Now in my manager class I call the loadExploreData method inside a RxCommand.
class ExploreManagerImplementation extends ExploreManager {
#override
RxCommand<void, List<ExploreEntity>> loadExploreDataCommand;
ExploreManagerImplementation() {
loadExploreDataCommand = RxCommand.createAsync<PaginationInput, List<ExploreEntity>>((input) =>
sl //Forget about this part
.get<ExploreServiceStruct>() //and this part if you couldn't understand it
.loadExploreData(input));
}
}
And finally I get the result by a RxLoader and pass it to a GridView if data was fetched successfully.
class ExplorePageState extends State<ExplorePage>{
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text("Explore"),
),
body: Column(children: <Widget>[
Expanded(
child: RxLoader<List<ExploreEntity>>(
commandResults:
sl.get<ExploreManager>().loadExploreDataCommand.results,
dataBuilder: (context, data) => ExploreGridView(data),
placeHolderBuilder: (context) => Center(
child: Center(
child: CircularProgressIndicator(),
),
),
errorBuilder: (context, error) => Center(
child: Text("Error"),
)),
)
]));
}
}
It works like a charm but when I wanted to load the data of the next page from web service and append it to the list, I couldn't find a solution to store the content of previous pages and just append the new page's contents to them, since data is passed along the RxCommand and RxLoader automatically.
When loadExploreData sends the reponse to the manager, I need to firstly append the result to a list, and then send that list as the result to RxLoader. Any suggestions?

Answer 1

Hmm that's a good question if this can be done just using Rx. What I would do is keeping a list of the received items in the manager. So when triggering the command to get the next page the command would first add the new data to the list and then push the whole list to the UI.
I"m curious if there is another solution.
My described approach in a rough code sample
class ExploreManagerImplementation extends ExploreManager {
List<ExploreEntity>> receivedData = <ExploreEntity>[];
#override
RxCommand<void, List<ExploreEntity>> loadExploreDataCommand;
ExploreManagerImplementation() {
loadExploreDataCommand = RxCommand.createAsync<PaginationInput, List<ExploreEntity>>((input)
async {
var newData = await sl //Forget about this part
.get<ExploreServiceStruct>() //and this part if you couldn't understand it
.loadExploreData(input);
receivedData.addAll(newData);
return receivedData;
};
}
}