Real-Time MultiChart

[File: phpdemo/realtimemultichart.php]
<?php
require_once("../lib/phpchartdir.php");

#
# Draw a single chart
#
function drawXYChart($viewer, $timeStamps, $dataSeries, $name, $color, $xAxisScale, $xAxisVisible) {
    # Only the last chart has an x-axis
    $xAxisHeight = 25;
    if (!$xAxisVisible) {
        $xAxisHeight = 0;
    }

    # Create an XYChart object of size 640 x 120 pixels (excluding x-axis height)
    $c = new XYChart(640, 120 + $xAxisHeight);

    # Set the plotarea at (55, 10) with width 85 pixels less than chart width, and height 20 pixels
    # less than chart height. Use a vertical gradient from light blue (f0f6ff) to sky blue (a0c0ff)
    # as background. Set border to transparent and grid lines to white (ffffff).
    $c->setPlotArea(55, 10, $c->getWidth() - 85, $c->getHeight() - 20 - $xAxisHeight,
        $c->linearGradientColor(0, 10, 0, $c->getHeight() - 20 - $xAxisHeight, 0xf0f6ff, 0xa0c0ff),
        -1, Transparent, 0xffffff, 0xffffff);

    # As the data can lie outside the plotarea in a zoomed chart, we need enable clipping.
    $c->setClipping();

    # Add a legend box at (55, 5) using horizontal layout. Use 8pts Arial Bold as font. Set the
    # background and border color to Transparent and use line style legend key.
    $b = $c->addLegend(55, 5, false, "Arial Bold", 10);
    $b->setBackground(Transparent);
    $b->setLineStyleKey();

    # Set the x and y axis stems to transparent and the label font to 10pt Arial
    $c->xAxis->setColors(Transparent);
    $c->yAxis->setColors(Transparent);
    $c->xAxis->setLabelStyle("Arial", 10);
    $c->yAxis->setLabelStyle("Arial", 10);

    # Add axis title using 10pts Arial Bold Italic font
    $c->yAxis->setTitle($name, "Arial Bold", 10);

    #================================================================================
    # Add data to chart
    #================================================================================

    # Add a line layer with the given data, with a line width of 2 pixels.
    $layer = $c->addLineLayer();
    $layer->setLineWidth(2);
    $layer->setXData($timeStamps);
    $layer->addDataSet($dataSeries, $color, $name);

    #================================================================================
    # Configure axis scale and labelling
    #================================================================================

    # For the automatic axis labels, set the minimum spacing to 30 pixels for the y axis.
    $c->yAxis->setTickDensity(30);

    if ($xAxisScale == null) {
        # If xAxisScale is given, then use it to synchronize with other charts.
        $c->xAxis->copyAxis($xAxisScale);
    } else {
        # Set the x-axis label format
        $c->xAxis->setLabelFormat("{value|hh:nn:ss}");
    }

    # Hide the x-axis if it is not visible.
    if (!$xAxisVisible) {
        $c->xAxis->setColors(Transparent, Transparent);
    }

    #================================================================================
    # Output the chart
    #================================================================================

    return $c;
}

#
# Draw the MultiChart
#
function drawChart($viewer) {
    #
    # Data to draw the chart. In this demo, the data buffer will be filled by a random data
    # generator. In real life, the data is probably stored in a buffer (eg. a database table, a text
    # file, or some global memory) and updated by other means.
    #

    # We use a data buffer to emulate the last 240 samples.
    $sampleSize = 240;
    $dataSeries1 = array_fill(0, $sampleSize, 0);
    $dataSeries2 = array_fill(0, $sampleSize, 0);
    $dataSeries3 = array_fill(0, $sampleSize, 0);
    $timeStamps = array_fill(0, $sampleSize, 0);

    # Our pseudo random number generator
    $firstDate = chartTime2(time()) - count($timeStamps);
    for($i = 0; $i < count($timeStamps); ++$i) {
        $p = $firstDate + $i;
        $timeStamps[$i] = $p;
        $dataSeries1[$i] = cos($p * 2.1) * 10 + 1 / (cos($p) * cos($p) + 0.01) + 20;
        $dataSeries2[$i] = 100 * sin($p / 27.7) * sin($p / 10.1) + 150;
        $dataSeries3[$i] = 100 * cos($p / 6.7) * cos($p / 11.9) + 150;
    }

    # The MultiChart, initially set to a height 10 pixels as the top margin.
    $m = new MultiChart(640, 10);

    # This first chart is responsible for setting up the x-axis scale.
    $xyc = drawXYChart($viewer, $timeStamps, $dataSeries1, "Alpha", 0xff0000, null, false);
    $xAxisScale = $xyc->xAxis;

    # Add the XYChart to the MultiChart and increase the MultiChart height
    $m->addChart(0, $m->getHeight(), $xyc);
    $m->setSize($m->getWidth(), $m->getHeight() + $xyc->getHeight());

    # All other charts synchronize their x-axes with that of the first chart.
    $xyc = drawXYChart($viewer, $timeStamps, $dataSeries2, "Beta", 0x008800, $xAxisScale, false);

    # Add the XYChart to the MultiChart and increase the MultiChart height
    $m->addChart(0, $m->getHeight(), $xyc);
    $m->setSize($m->getWidth(), $m->getHeight() + $xyc->getHeight());

    # The last chart displays the x-axis.
    $xyc = drawXYChart($viewer, $timeStamps, $dataSeries3, "Gamma", 0x0000ff, $xAxisScale, true);

    # Add the XYChart to the MultiChart and increase the MultiChart height
    $m->addChart(0, $m->getHeight(), $xyc);
    $m->setSize($m->getWidth(), $m->getHeight() + $xyc->getHeight());

    # Set the combined plot area to be the bounding box of the plot areas of the 3 charts
    $m->setMainChart($m);

    # Output the chart
    $viewer->setChart($m, SVG);

    # Output Javascript chart model to the browser to support tracking cursor
    $viewer->setChartModel($m->getJsChartModel());
}

#
# This script handles both the full page request, as well as the subsequent partial updates (AJAX
# chart updates). We need to determine the type of request first before we processing it.
#

# Create the WebChartViewer object
$viewer = new WebChartViewer("chart1");

if ($viewer->isPartialUpdateRequest()) {
    # Is a partial update request. Draw the chart and perform a partial response.
    drawChart($viewer);
    print($viewer->partialUpdateChart());
    exit();
}

#
# If the code reaches here, it is a full page request.
#

drawChart($viewer);
?>

<!DOCTYPE html>
<html>
<head>
    <title>Real Time MultiChart</title>
    <script type="text/javascript" src="cdjcv.js"></script>
</head>
<body style="margin:0px">
<script type="text/javascript">

//
// Execute the following initialization code after the web page is loaded
//
JsChartViewer.addEventListener(window, 'load', function() {
    var viewer = JsChartViewer.get('<?php echo $viewer->getId() ?>');

    // Draw track cursor when mouse is moving over plotarea. Hide it when mouse leaves plot area.
    viewer.attachHandler(["MouseMovePlotArea", "TouchStartPlotArea", "TouchMovePlotArea", "ChartMove",
        "PostUpdate", "Now"], function(e) {
        this.preventDefault(e);   // Prevent the browser from using touch events for other actions
        multiTrackLineLabel(viewer, viewer.getPlotAreaMouseX());
    });

    // When the chart is being updated, by default, an "Updating" box will pop up. In this example, we
    // will disable this box.
    viewer.updatingMsg = "";
});

//
// Draw track line for a MultiChart
//
function multiTrackLineLabel(viewer, mouseX)
{
    // Remove all previously drawn tracking object
    viewer.hideObj("all");

    // Use a loop to draw track labels for the XYCharts inside the MultiChart
    for (var i = 0; i < viewer.getChartCount(); ++i)
        // Only the bottom chart (i == viewer.getChartCount() - 1) needs x-axis label.
        xyChartTrackLabel(viewer, mouseX, viewer.getChart(i), i, i == viewer.getChartCount() - 1);
}

//
// Draw xy chart track label
//
function xyChartTrackLabel(viewer, mouseX, c, id, needXAxisLabel)
{
    // The plot area
    var plotArea = c.getPlotArea();

    // The XYChart API object obtains the various coordinates relative to the top-left corner
    // of the XYChart. However, it needs to draw the track cursor on the MultiChart. So we need
    // to obtain the coordinates of the XYChart top-left corner inside the MultiChart.
    var originX = c.getAbsOffsetX();
    var originY = c.getAbsOffsetY();

    // Get the data x-value that is nearest to the mouse, and find its pixel coordinate.
    var xValue = c.getNearestXValue(mouseX);
    var xCoor = originX + c.getXCoor(xValue);

    // Draw a vertical track line at the x-position
    viewer.drawVLine("trackLine_" + id, xCoor, originY + plotArea.getTopY(),
        originY + plotArea.getBottomY(), "black 1px dotted");

    // Only the last chart needs to draw the x-axis label
    if (needXAxisLabel)
    {
        viewer.showTextBox("xAxisLabel_" + id, xCoor, originY + plotArea.getBottomY()
            + 5, JsChartViewer.Top, c.xAxis().getFormattedLabel(xValue, "hh:nn:ss"),
            "font:bold 13px Arial;color:#FFFFFF;background-color:#000000;padding:0px 3px");
    }

    // Iterate through all layers to draw the data labels
    for (var i = 0; i < c.getLayerCount(); ++i)
    {
        var layer = c.getLayerByZ(i);

        // The data array index of the x-value
        var xIndex = layer.getXIndexOf(xValue);

        // Iterate through all the data sets in the layer
        for (var j = 0; j < layer.getDataSetCount(); ++j)
        {
            var dataSet = layer.getDataSetByZ(j);

            // Get the color and position of the data label
            var color = dataSet.getDataColor();
            var yCoor = c.getYCoor(dataSet.getPosition(xIndex), dataSet.getUseYAxis());

            // Draw a track dot with a label next to it for visible data points in the plot area
            if ((yCoor != null) && (yCoor >= plotArea.getTopY()) && (yCoor <= plotArea.getBottomY())
                && (color != null))
            {
                viewer.showTextBox("dataPoint_" + id + "_" + i + "_" + j, xCoor,
                    originY + yCoor, JsChartViewer.Center, viewer.htmlRect(7, 7, color));

                viewer.showTextBox("dataLabel" + id + "_" + i + "_" + j, xCoor + 5,
                    originY + yCoor, JsChartViewer.Left, dataSet.getValue(xIndex).toPrecision(4),
                    "padding:0px 3px;font:bold 13px Arial;background-color:" + color +
                    ";color:#FFFFFF;-webkit-text-size-adjust:100%;");
            }
        }
    }
}

//
// Executes once every second to update the countdown display. Updates the chart when the countdown reaches 0.
//
function timerTick()
{
    // Get the update period and the time left
    var updatePeriod = parseInt(document.getElementById("UpdatePeriod").value);
    var timeLeft = Math.min(parseInt(document.getElementById("TimeRemaining").innerHTML), updatePeriod) - 1;

    if (timeLeft == 0)
        // Can update the chart now
        JsChartViewer.get('<?php echo $viewer->getId() ?>').partialUpdate();
    else if (timeLeft < 0)
        // Reset the update period
        timeLeft += updatePeriod;

    // Update the countdown display
    document.getElementById("TimeRemaining").innerHTML = timeLeft;
}
window.setInterval("timerTick()", 1000);

</script>
<table cellspacing="0" cellpadding="0" border="0">
    <tr>
        <td align="right" colspan="2" style="background:#000088; color:#ffff00; padding:0px 4px 2px 0px;">
            <a style="color:#FFFF00; font:italic bold 10pt Arial; text-decoration:none" href="http://www.advsofteng.com/">
                Advanced Software Engineering
            </a>
        </td>
    </tr>
    <tr valign="top">
        <td style="width:150px; background:#c0c0ff; border-right:black 1px solid; border-bottom:black 1px solid;">
            <br />
            <br />
            <div style="font: 9pt Verdana; padding:10px;">
                <b>Update Period</b><br />
                <select id="UpdatePeriod" style="width:130px">
                    <option value="5" selected="selected">5</option>
                    <option value="10">10</option>
                    <option value="20">20</option>
                    <option value="30">30</option>
                    <option value="60">60</option>
                </select>
            </div>
            <div style="font:9pt Verdana; padding:10px;">
                <b>Time Remaining</b><br />
                <div style="width:128px; border:#888888 1px inset;">
                    <div style="margin:3px" id="TimeRemaining">0</div>
                </div>
            </div>
        </td>
        <td>
            <div style="font: bold 20pt Arial; margin:5px 0px 0px 5px;">
                Real Time MultiChart
            </div>
            <hr style="border:solid 1px #000080" />
            <div style="padding:0px 5px 5px 10px">
                <!-- ****** Here is the chart image ****** -->
                <?php echo $viewer->renderHTML() ?>
            </div>
        </td>
    </tr>
</table>
</body>
</html>