Can't dynamically update CandlestickSeries in QtCharts

SlayH

import QtQuick 2.15
import QtCharts 2.15

Rectangle{
  width: 400;
  height: 400;
  radius: 40;
  property alias series: series;

  ChartView{
    id: chartView;
    anchors.fill: parent;
    title: "Candlestick Chart";
    legend.visible: false;
    antialiasing: true;

    CandlestickSeries{
      id: series;
      increasingColor: "green";
      decreasingColor: "red";

      function updateData(){
        series.clear();
        console.log("updateData called");
        for (var i = 0; i < stockProvider.stockData.length / 10; i++) {
          console.log(stockProvider.stockData[i].timestamp);
          var candlestick = Qt.createQmlObject(
            "import QtQuick 2.15; import QtCharts 2.15; CandlestickSet { " +
            "timestamp: " + stockProvider.stockData[i].timestamp + "; " +
            "open: " + stockProvider.stockData[i].open + "; " +
            "high: " + stockProvider.stockData[i].high + "; " +
            "low: " + stockProvider.stockData[i].low + "; " +
            "close: " + stockProvider.stockData[i].close + "; " +
            "}", series
            );
          series.append(candlestick);
          console.log(stockProvider.stockData[i].open);
        }
      }
    }
  }
}

This is how I tried to update the CandlestickSeries dynamically but it doesn't work. I had console.log the data for debug purposes and they are all present. For some reason the graph remains blank. Can someone help me please?

Bob64

Have you looked at HCandlestickModelMapper/VCandlestickModelMapper? It might be a better way to tie your series to a dynamic source of data.

SlayH

Okay thanks I will give it a try.

SlayH

import QtQuick 2.15
import QtCharts 2.15

Rectangle{
  width: 400;
  height: 400;
  radius: 40;

  ChartView{
    id: chartView;
    anchors.fill: parent;
    title: "Candlestick Chart";
    legend.visible: false;
    antialiasing: true;

    CandlestickSeries{
      id: series;
      increasingColor: "green";
      decreasingColor: "red";

      VCandlestickModelMapper{
        id: modelMapper;
        model: candleStickModel;
        timestampRow: 1;
        openRow: 2;
        highRow: 3;
        lowRow: 4;
        closeRow: 5;
        onModelChanged: {
            console.log("Candlestick series data model updated");
        }
      }
    }
  }
}

QVariant CandleStickModel::data(const QModelIndex &index, int role) const {
    if (!index.isValid() || index.row() >= _candleStickData.size()) {
        return QVariant();
    }

    const class ::CandleStickData *candle{_candleStickData.at(index.row())};

    switch (CandleStickRoles(role)) {
    case TimestampRole:
        return candle->timestamp();
    case OpenRole:
        return candle->open();
    case CloseRole:
        return candle->close();
    case HighRole:
        return candle->high();
    case LowRole:
        return candle->low();
    default:
        return QVariant();
    }

    return QVariant();
}

I tried using a VCandlestickModelMapper but it still doesn't work. Where did I go wrong please?

Kiovtorov

Did you solve it?