- Qt 5.3
- Qt Quick
- Qt Quick Demo - StocQt
- StockModel.qml Example File
- Qt 5.3.2 Reference Documentation

# StockModel.qml Example File

demos/stocqt/content/StockModel.qml

    /****************************************************************************
    **
    ** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
    ** Contact: http://www.qt-project.org/legal
    **
    ** This file is part of the examples of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:BSD$
    ** You may use this file under the terms of the BSD license as follows:
    **
    ** "Redistribution and use in source and binary forms, with or without
    ** modification, are permitted provided that the following conditions are
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    **     the documentation and/or other materials provided with the
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    **     of its contributors may be used to endorse or promote products derived
    **     from this software without specific prior written permission.
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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) {
            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;
                            model.dataReady(); //emit signal
                        }
                    }
                }
            }
            xhr.send()
        }
    }