yahoo_finance_data_reader 1.0.0

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

This project started as a migration of the pandas datareader functionality to read yahoo finance stock prices. In December of 2022 yahoo started to encrypt the data in the HTML, so I needed to investigate

https://github.com/pydata/pandas-datareader/blob/main/pandas_datareader/yahoo/daily.py

This lib have a strong advantage on backtesting strategies as it can give all the dataframe in yahoo finance, this means that can get daily data on futures like NQ=F and ES=F since 2000 and it goes as far as getting data from 1927 on the SP500 yahoo finance symbol ^GSPC

Features

Get daily data from yahoo finance for the entire dataframe available

Getting started

Add the dependency to your pubspec.yaml:

yahoo_finance_data_reader: ^1.0.0

Usage

YahooFinanceResponse data = await yahooFinance.getDailyDTOs('GOOG');

Additional information

To include in your app as a widget you can start with this future builder and debug your way until your desired result

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)}'),
              ],
            ),
          ],
        ),
      ),
    );
  }
}

Like us on pub.dev

Package url: https://pub.dev/packages/yahoo_finance_data_reader

Instruction to publish the package to pub.dev

dart pub publish