StockModel.qml Example File | Qt 5.12

- Qt 5.12
- Qt Quick Demo - StocQt
- StockModel.qml Example File
- Qt 5.12.9 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()
         }
     }