Flutter FutureBuilder widget dynamic list lenght

Question

I am trying to make dynamic ListView.builder in FutureBuilder widget but can't get lenght of list which comes from AsyncSnapshot snapshot. I've tried itemCount: snapshot.data.lenght but it did not work. Here is my code

class FlutterDemo extends StatelessWidget {
  final QuoteStorage storage;

  FlutterDemo({Key key, @required this.storage}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Scrapy on flutter')),
      body: Center(
        child: FutureBuilder(
            future: storage.getQuotes(),
            builder: (context, AsyncSnapshot<Quotes> snapshot) {
              return snapshot.hasData ? ListView.builder(
                itemCount: snapshot.data.lenght,
                itemBuilder: (context, index) {
                  final quotes = snapshot.data;
                  return Card(
                      child: Padding(
                        padding: const EdgeInsets.all(8.0),
                        child: Text(quotes.items[index].quote),
                      ));
                },
              )
                  : const CircularProgressIndicator();
            }),
      ),
    );
  }
}

Data comes from class Quotes:

class Quotes extends Items {
  @override
  final List<Quote> items;
  Quotes({
    this.items,
  });

  factory Quotes.fromJson(String str) => Quotes.fromMap(json.decode(str));
  factory Quotes.fromMap(Map<String, dynamic> json) => Quotes(
        items: json["items"] == null
            ? null
            : List<Quote>.from(json["items"].map((x) => Quote.fromMap(x))),
      );
}

And quotes storage class used to build future:

class QuoteStorage {
  // ...
  // ...
  Future<Quotes> getQuotes() async {
    final file = await _localFile;
    final contents = await file.readAsString();
    return Quotes.fromJson(contents);
  }
}

App is crashing if I don't provide itemCount which is dynamic (fetch from url). Any ideas?

Answer 1

You are getting the error because you spelt length wrong.

You can fix this by correcting the spelling of length. Replace your FlutterDemo class with the code below

It works perfectly fine.

class FlutterDemo extends StatelessWidget {
  final QuoteStorage storage;

  FlutterDemo({Key key, @required this.storage}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Scrapy on flutter')),
      body: Center(
        child: FutureBuilder(
            future: storage.getQuotes(),
            builder: (context, AsyncSnapshot<Quotes> snapshot) {
              return snapshot.hasData ? ListView.builder(
                // current the spelling of length here
                itemCount: snapshot.data.length,
                itemBuilder: (context, index) {
                  final quotes = snapshot.data;
                  return Card(
                      child: Padding(
                        padding: const EdgeInsets.all(8.0),
                        child: Text(quotes.items[index].quote),
                      ));
                },
              )
                  : const CircularProgressIndicator();
            }),
      ),
    );
  }
}

I hope this helps.