Real-Time Chart with Snapshot

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

#
# 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;
}

# Create an XYChart object 600 x 320 pixels in size
$c = new XYChart(600, 320);

# Set the plotarea at (55, 60) and of size 520 x 235 pixels with transparent background and border.
# Enable both horizontal and vertical grids by setting their colors to grey (cccccc). Set clipping
# mode to clip the data lines to the plot area.
$c->setPlotArea(55, 60, 520, 235, -1, -1, Transparent, 0xcccccc, 0xcccccc);
$c->setClipping();

# Add a title to the chart using dark grey (0x333333) 20pt Arial Bold font
$c->addTitle("Real-Time Chart with Snapshot", "Arial Bold", 20, 0x333333);

# Add a legend box at the top of the plot area using horizontal layout. Use 10pt Arial Bold font,
# transparent background and border, and line style legend icon.
$b = $c->addLegend(55, 30, false, "Arial Bold", 10);
$b->setBackground(Transparent, 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 y-axis title using 12pt Arial font
$c->yAxis->setTitle("Y-Axis Title Placeholder", "Arial", 12);

# For the automatic x and y axis labels, set the minimum spacing to 75 and 30 pixels.
$c->xAxis->setTickDensity(75);
$c->yAxis->setTickDensity(30);

# Set the x-axis label format
$c->xAxis->setLabelFormat("{value|hh:nn:ss}");

# Create a line layer to plot the lines
$layer = $c->addLineLayer2();

# The x-coordinates are the timeStamps.
$layer->setXData($timeStamps);

# The 3 data series are used to draw 3 lines. Here we put the latest data values as part of the data
# set name, so you can see them updated in the legend box.
$layer->addDataSet($dataSeries1, 0xff0000, $c->formatValue($dataSeries1[count($dataSeries1) - 1],
    "Alpha: {value|2}"));
$layer->addDataSet($dataSeries2, 0x00cc00, $c->formatValue($dataSeries2[count($dataSeries2) - 1],
    "Beta: {value|2}"));
$layer->addDataSet($dataSeries3, 0x0000ff, $c->formatValue($dataSeries3[count($dataSeries3) - 1],
    "Gamma: {value|2}"));

# Create the WebChartViewer to output the chart
$viewer = new WebChartViewer("ChartImage1");

# Check if is download request
$downloadFormat = isset($_REQUEST["download"]) ? $_REQUEST["download"] : null;
if (!(($downloadFormat == null) || ($downloadFormat == ""))) {
    $fname = "demo_" . $c->formatValue($timeStamps[count($timeStamps) - 1], "yyyymmddhhnnss");
    if ($downloadFormat == "pdf") {
        # Output in PDF and stream as attachment
        $viewer->streamAttachment($c->makeChart2(PDF), "$fname.pdf");
        exit();
    } else {
        # Output in PNG and stream as attachment
        $viewer->streamAttachment($c->makeChart2(PNG), "$fname.png");
        exit();
    }
}

# Check if is a stream request to update the chart
if ($viewer->isStreamRequest()) {
    # Stream the updated chart to the browser
    $viewer->streamChart($c->makeChart2(SVG));
    exit();
}

# Is the initial web page request. Output chart as usual.
$viewer->setChart($c, SVG);
?>

<!DOCTYPE html>
<html>
<head>
    <title>Real-Time Chart with Snapshot</title>
    <script type="text/javascript" src="cdjcv.js"></script>
</head>
<body style="margin:0px">
<table cellspacing="0" cellpadding="0" style="border:black 1px solid;">
    <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:130px; background:#c0c0ff; border-right:black 1px solid; border-bottom:black 1px solid;">
            <br />
            <br />
            <div style="font:12px Verdana; padding:10px;">
                <b>Update Period</b><br />
                <select id="UpdatePeriod" style="width:110px">
                    <option value="5">5</option>
                    <option value="10" selected="selected">10</option>
                    <option value="20">20</option>
                    <option value="30">30</option>
                    <option value="60">60</option>
                </select>
                <br /><br /><br />
                <b>Time Remaining</b><br />
                <div style="width:108px; border:#888888 1px inset;">
                    <div style="margin:3px" id="TimeRemaining">0</div>
                </div>
            </div>
            <br />
            <br />
            <br />
            <br />
            <div style="text-align:center">
                <input type="button" value="Download PDF" style="width:112px; font:10pt Arial"
                    onclick="JsChartViewer.get('ChartImage1').partialUpdateAsAttachment('download=pdf');" /><br/>
                <input type="button" value="Download PNG" style="width:112px; font:10pt Arial; margin-top:8px;"
                    onclick="JsChartViewer.get('ChartImage1').partialUpdateAsAttachment('download=png');" />
            </div>
        </td>
        <td style="border-left:black 1px solid; padding:5px 0px 0px 5px;" >
            <!-- ****** Here is the chart image ****** -->
            <?php echo $viewer->renderHTML(); ?>
        </td>
    </tr>
</table>
<script type="text/javascript">

//
// 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('ChartImage1').streamUpdate();
    else if (timeLeft < 0)
        // Reset the update period
        timeLeft += updatePeriod;

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

</script>
</body>
</html>