yahoo_finance_data_reader 1.0.4

Data reader for yahoo finance to get daily stocks prices. It can be used to develop backtests and it can get all the historic daily data on yahoo finance

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:yahoo_finance_data_reader/yahoo_finance_data_reader.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      home: BottomSelectionWidget(),
    );
  }
}

class BottomSelectionWidget extends StatefulWidget {
  const BottomSelectionWidget({super.key});

  @override
  State<BottomSelectionWidget> createState() => _BottomSelectionWidgetState();
}

class _BottomSelectionWidgetState extends State<BottomSelectionWidget> {
  int _selectedIndex = 0;
  final PageController _pageController = PageController();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Yahoo Finance Example'),
      ),
      body: Container(
        padding: const EdgeInsets.all(20.0),
        child: PageView(
          physics: NeverScrollableScrollPhysics(),
          controller: _pageController,
          onPageChanged: _onItemSelected,
          children: [
            YahooFinanceServiceWidget(),
            DTOSearch(),
            RawSearch(),
          ],
        ),
      ),
      bottomNavigationBar: BottomNavigationBar(
        onTap: _onItemSelected,
        currentIndex: _selectedIndex,
        items: const [
          BottomNavigationBarItem(
            icon: Icon(Icons.storage),
            label: 'Service',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.format_list_numbered),
            label: 'DTO',
          ),
          BottomNavigationBarItem(
            icon: Icon(Icons.raw_on),
            label: 'Raw',
          ),
        ],
      ),
    );
  }

  void _onItemSelected(int index) {
    setState(() {
      _pageController.animateToPage(index,
          duration: const Duration(milliseconds: 200), curve: Curves.easeOut);
      _selectedIndex = index;
    });
    print(index.toString());
  }
}

class RawSearch extends StatefulWidget {
  const RawSearch({
    super.key,
  });

  @override
  State<RawSearch> createState() => _RawSearchState();
}

class _RawSearchState extends State<RawSearch> {
  @override
  Widget build(BuildContext context) {
    String ticker = 'GOOG';
    YahooFinanceDailyReader yahooFinanceDataReader = YahooFinanceDailyReader();

    Future<Map<String, dynamic>> future =
        yahooFinanceDataReader.getDailyData(ticker);

    return FutureBuilder(
      future: future,
      builder:
          (BuildContext context, AsyncSnapshot<Map<String, dynamic>> snapshot) {
        if (snapshot.connectionState == ConnectionState.done) {
          if (snapshot.data == null) {
            return const Text('No data');
          }

          Map<String, dynamic> historicalData = snapshot.data!;
          return SingleChildScrollView(
            child: Text(historicalData.toString()),
          );
        } else if (snapshot.hasError) {
          return Text('Error ${snapshot.error}');
        }

        return const Center(
          child: SizedBox(
            height: 50,
            width: 50,
            child: CircularProgressIndicator(),
          ),
        );
      },
    );
  }

  String generateDescription(DateTime date, Map<String, dynamic> day) {
    return '''$date
open: ${day['open']}
close: ${day['close']}
high: ${day['high']}
low: ${day['low']}
adjclose: ${day['adjclose']}
''';
  }
}

class DTOSearch extends StatefulWidget {
  const DTOSearch({super.key});

  @override
  State<DTOSearch> createState() => _DTOSearchState();
}

class _DTOSearchState extends State<DTOSearch> {
  final TextEditingController controller = TextEditingController(
    text: 'GOOG',
  );
  late Future<YahooFinanceResponse> future;

  @override
  void initState() {
    super.initState();
    load();
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        const Text('Ticker from yahoo finance'),
        TextField(
          controller: controller,
        ),
        MaterialButton(
          onPressed: load,
          child: Text('Load'),
          color: Theme.of(context).primaryColor,
        ),
        Expanded(
          child: FutureBuilder(
            future: future,
            builder: (BuildContext context,
                AsyncSnapshot<YahooFinanceResponse> snapshot) {
              if (snapshot.connectionState == ConnectionState.done) {
                if (snapshot.data == null) {
                  return Text('No data');
                }

                YahooFinanceResponse response = snapshot.data!;
                return ListView.builder(
                    itemCount: response.candlesData.length,
                    itemBuilder: (BuildContext context, int index) {
                      YahooFinanceCandleData candle =
                          response.candlesData[index];

                      return _CandleCard(candle);
                    });
              } else {
                return const Center(
                  child: SizedBox(
                    height: 50,
                    width: 50,
                    child: CircularProgressIndicator(),
                  ),
                );
              }
            },
          ),
        ),
      ],
    );
  }

  void load() {
    future = YahooFinanceDailyReader().getDailyDTOs(controller.text);
    setState(() {});
  }
}

class _CandleCard extends StatelessWidget {
  final YahooFinanceCandleData candle;
  const _CandleCard(this.candle);

  @override
  Widget build(BuildContext context) {
    final String date = candle.date.toIso8601String().split('T').first;

    return Card(
      child: Container(
        margin: const EdgeInsets.all(10),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                Text(date),
              ],
            ),
            const SizedBox(
              height: 10,
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                Text('open: ${candle.open.toStringAsFixed(2)}'),
                Text('close: ${candle.close.toStringAsFixed(2)}'),
              ],
            ),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
              children: [
                Text('low: ${candle.low.toStringAsFixed(2)}'),
                Text('high: ${candle.high.toStringAsFixed(2)}'),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

class YahooFinanceServiceWidget extends StatefulWidget {
  const YahooFinanceServiceWidget({super.key});

  @override
  State<YahooFinanceServiceWidget> createState() =>
      _YahooFinanceServiceWidgetState();
}

class _YahooFinanceServiceWidgetState extends State<YahooFinanceServiceWidget> {
  TextEditingController controller = TextEditingController(
    text: 'GOOG',
  );
  List<YahooFinanceCandleData> pricesList = [];
  List? cachedPrices;
  bool loading = true;

  @override
  void initState() {
    super.initState();
    load();
  }

  void load() async {
    loading = false;
    setState(() {});

    // Get response for the first time
    pricesList = await YahooFinanceService().getTickerData(controller.text);

    // Check if the cache was created
    cachedPrices = await YahooFinanceDAO().getAllDailyData(controller.text);
    loading = false;
    setState(() {});
  }

  void deleteCache() async {
    loading = true;
    setState(() {});

    await YahooFinanceDAO().removeDailyData(controller.text);
    cachedPrices = await YahooFinanceDAO().getAllDailyData(controller.text);
    loading = false;
    setState(() {});
  }

  void refresh() async {
    cachedPrices = await YahooFinanceDAO().getAllDailyData(controller.text);
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    if (loading) {
      return const Center(
        child: CircularProgressIndicator(),
      );
    }

    return ListView.builder(
      itemCount: pricesList.length + 1,
      itemBuilder: (context, i) {
        if (i == 0) {
          final List<String> tickerOptions = [
            'GOOG',
            'ES=F, GC=F',
            'GOOG, AAPL'
          ];
          return Card(
            child: Container(
              margin: const EdgeInsets.all(10),
              child: Column(
                children: [
                  Row(
                    children: tickerOptions
                        .map(
                          (option) => Container(
                            margin: const EdgeInsets.all(5),
                            child: MaterialButton(
                              child: Text(option),
                              onPressed: controller.text == option
                                  ? null
                                  : () => setState(() {
                                        controller.text = option;
                                      }),
                              color: Colors.amberAccent,
                            ),
                          ),
                        )
                        .toList(),
                  ),
                  Text('Ticker from yahoo finance:'),
                  TextField(
                    controller: controller,
                  ),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                    children: [
                      MaterialButton(
                        color: Theme.of(context).primaryColor,
                        onPressed: () => load(),
                        child: const Text('Load'),
                      ),
                      MaterialButton(
                        color: Theme.of(context).colorScheme.error,
                        onPressed: () => deleteCache(),
                        child: const Text('Delete Cache'),
                      ),
                      MaterialButton(
                        color: Theme.of(context).colorScheme.onPrimary,
                        onPressed: () => refresh(),
                        child: const Text('Refresh'),
                      ),
                    ],
                  ),
                  Text('Prices in the service ${pricesList.length}'),
                  Text('Prices in the cache ${cachedPrices?.length}'),
                  pricesList.isEmpty
                      ? const Text('No data')
                      : const SizedBox.shrink()
                ],
              ),
            ),
          );
        } else {
          final YahooFinanceCandleData candleData = pricesList[i - 1];
          return _CandleCard(candleData);
        }
      },
    );
  }
}