Qt 5.7 | Qt Quick | Qt Quick Demo - StocQt | StockModel.qml Example File

Qt 5.7.1 Reference Documentation

# StockModel.qml Example File

demos/stocqt/content/StockModel.qml

      /****************************************************************************
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      ** This file is part of the examples of the Qt Toolkit.
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      import QtQuick 2.0

      ListModel {
          id: model
          property string stockId: ""
          property string stockName: ""
          property string stockDataCycle: "d"
          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;

              var newest = new Date(model.get(0).date);
              var oldest = new Date(model.get(model.count - 1).date);
              if (newest <= date)
                  return -1;

              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;
                  }
                  if (currDiff > bestDiff)
                      return retval;
              }

              return -1;
          }

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

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

              var endDate = new Date(); //today

              if (stockDataCycle !== "d" && stockDataCycle !== "w" && stockDataCycle !== "m")
                  stockDataCycle = "d";

              /*
                  Fetch stock data from yahoo finance:
                   url: http://ichart.finance.yahoo.com/table.csv?s=NOK&a=5&b=11&c=2010&d=7&e=23&f=2010&g=d&ignore=.csv
                      s:stock name/id, a:start day, b:start month, c:start year  default: 25 April 1995, oldest c= 1962
                      d:end day, e:end month, f:end year, default:today  (data only available 3 days before today)
                      g:data cycle(d daily,  w weekly, m monthly, v Dividend)
                */
              var request = "http://ichart.finance.yahoo.com/table.csv?";
              request += "s=" + stockId;
              request += "&a=" + startDate.getMonth();
              request += "&b=" + startDate.getDate();
              request += "&c=" + startDate.getFullYear();
              request += "&d=" + endDate.getMonth();
              request += "&e=" + endDate.getDate();
              request += "&f=" + endDate.getFullYear();
              request += "&g=" + stockDataCycle;
              request += "&ignore=.csv";
              return request;
          }

          function createStockPrice(r) {
              return {
                      "date": r[0],
                      "open":r[1],
                      "high":r[2],
                      "low":r[3],
                      "close":r[4],
                      "volume":r[5],
                      "adjusted":r[6]
                     };
          }

          function updateStock() {
              var req = requestUrl();

              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 === 7)
                              model.append(createStockPrice(r));
                      }

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