Qt 5.11 | Qt Quick | Qt Quick Demo - StocQt | StockModel.qml Example File

Qt 5.11.3 Reference Documentation

# StockModel.qml Example File

demos/stocqt/content/StockModel.qml

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      import QtQuick 2.0

      ListModel {
          id: model
          property string stockId: ""
          property string stockName: ""
          property var newest
          property var oldest
          property bool ready: false
          property real stockPrice: 0.0
          property real stockPriceChanged: 0.0

          signal dataReady

          function indexOf(date) {
              if (model.count == 0)
                  return -1;

              if (newest <= date)
                  date = new Date(newest.getYear(),
                                  newest.getMonth(),
                                  newest.getDate() - 7);

              if (oldest >= date)
                  return model.count - 1;

              var currDiff = 0;
              var bestDiff = Math.abs(date.getTime() - newest.getTime());
              var retval = 0;
              for (var i = 0; i < model.count; i++) {
                  var d = new Date(model.get(i).date);
                  currDiff = Math.abs(d.getTime() - date.getTime());
                  if (currDiff < bestDiff) {
                      bestDiff = currDiff;
                      retval = i + 1;
                  }
                  if (currDiff > bestDiff)
                      return retval;
              }
              return -1;
          }

          function createStockPrice(r) {
              return {
                      "date": r[0],
                      "open":r[1],
                      "high":r[2],
                      "low":r[3],
                      "close":r[4],
                      "volume":r[5],
                     };
          }

          function updateStock() {
              if (stockId === "")
                  return;

              var startDate = new Date(2011, 4, 25);
              var endDate = new Date(); //today

              var req = "data/" + stockId + ".csv"
              if (!req)
                  return;

              var xhr = new XMLHttpRequest;

              xhr.open("GET", req, true);

              model.ready = false;
              model.clear();
              var i = 1; //skip the first line
              xhr.onreadystatechange = function() {
                  if (xhr.readyState === XMLHttpRequest.LOADING || xhr.readyState === XMLHttpRequest.DONE) {
                      var records = xhr.responseText.split('\n');
                      for (;i < records.length; i++ ) {
                          var r = records[i].split(',');
                          if (r.length >= 6)
                              model.append(createStockPrice(r));
                      }

                      if (xhr.readyState === XMLHttpRequest.DONE) {
                          if (model.count > 0) {
                              model.ready = true;
                              model.stockPrice = model.get(0).close;
                              model.stockPriceChanged = model.count > 1 ? (Math.round((model.stockPrice - model.get(1).close) * 100) / 100) : 0;
                              newest = new Date(model.get(0).date);
                              oldest = new Date(model.get(model.count - 1).date);
                          } else {
                              model.stockPrice = 0;
                              model.stockPriceChanged = 0;
                          }
                          model.dataReady(); // emit signal - model.ready indicates whether the data is valid
                      }
                  }
              }
              xhr.send()
          }
      }