flutter addAll isn't defined for Iterable - json

Question

I need your help for the following problem on line 22.
Flutter says, that "addAll isn't defined for Iterable". What do I need to change in my code or do you need additional Information?
import 'package:flutter/material.dart';
import 'package:MyApp/jsonApi/dataModels/dataModelPlaces.dart';
import 'package:MyApp/jsonApi/parsers/repositoryPlaces.dart';
class ShareAppScreen extends StatefulWidget {
#override
_ShareAppScreenState createState() => _ShareAppScreenState();
}
class _ShareAppScreenState extends State<ShareAppScreen> {
//List<DataModelPlaces> _places = <DataModelPlaces>[];
Iterable<DataModelPlaces> _places = <DataModelPlaces>[];
Iterable<DataModelPlaces> _placesDisplay = <DataModelPlaces>[];
bool _isPlacesLoading = false;
#override
void initState() {
super.initState();
fetchPlaces().then((pvalue) {
setState(() {
_isPlacesLoading = false;
_places.addAll(pvalue); //<- here I have a problem that addAll isn't defined for Iterable
_placesDisplay = _places;
print('User display pin Records: ${pvalue.data!.length}');
var i=0;
while (i < pvalue.data!.length){
print('User display Lat of $i: ${pvalue.data![i].attributes!.latitude}');
print('User display Long of $i: ${pvalue.data![i].attributes!.latitude}');
i++;
}
});
});
}
List stocksList = [
CompanyStocks(name: "Intel Corp", price: 56.96),
CompanyStocks(name: "HP Inc", price: 32.43),
CompanyStocks(name: "Apple Inc", price: 133.98),
CompanyStocks(name: "Microsoft Corporation", price: 265.51)
];
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('Users List ${_places.length}'),
),
body: SafeArea(
child: Container(
child: ListView.builder(
itemCount: stocksList.length,
itemBuilder: (context, index) {
return Card(
child: Padding(
padding: EdgeInsets.all(10),
child: ListTile(
title: Text(
stocksList[index].name,
style: TextStyle(
fontSize: 20,
),
),
leading: CircleAvatar(
child: Text(
stocksList[index].name[0],
style: TextStyle(fontSize: 15, fontWeight: FontWeight.bold),
),
),
trailing: Text("\$ ${stocksList[index].price}"),
),
),
);
},
),
),
),
);
}
}
class CompanyStocks {
String name;
double price;
CompanyStocks({required this.name,required this.price});
}
At the End I would need an Variable "_places" and "_placesDisplay" of DataModelPlaces which I can use in in Place of the List "stocksList" which is working but not _places / _placesDisplay"
Many Thanks
Roman

Answer 1

Iterable does not have .addAll. You need to convert it to a List first so you can addAll the elements to it such as:
Update: My bad. toList() will return a new list! You should try the alternative approach below
// This wrong since it will return a new list (wrong)
// _places.toList().addAll(pvalue)
Alternatively, you can change the definition to be List instead of Iterable:
from:
Iterable<DataModelPlaces> _places = <DataModelPlaces>[];
Iterable<DataModelPlaces> _placesDisplay = <DataModelPlaces>[];
To:
List<DataModelPlaces> _places = <DataModelPlaces>[];
List<DataModelPlaces> _placesDisplay = <DataModelPlaces>[];
Update:
As discussed in the comments, you want to make sure that fetchPlaces is returning an Iterable in order to use _places.addAll(pvalue) otherwise, if it's a single object, use _places.add(pvaule).