A basic example of AJAX

This is a basic example of using AJAX to request the data from the server. The window.onload function initiates the AJAX request and then the callback function - DrawGraph() - takes the response and creates the chart.

Note: In October 2013 a new CSV reader was added to RGraph. It makes reading CSV files much easier. You can read about the new CSV reader here.

This goes in the documents header:

<script src="RGraph.common.core.js"></script>
<script src="RGraph.line.js"></script>

Put this where you want the chart to show up:

<canvas id="cvs" width="600" height="250">
    [No canvas support]
</canvas>

This is the code that generates the chart:

<script>
    /**
    * Ths window.onload function initiates the AJAX request. The AJAX page is: http://www.rgraph.net/getdata.html
    * If you view this in your browser you'll see that all it does is output a sequence of numbers.
    */
    window.onload = function ()
    {
        RGraph.AJAX('/getdata.html', DrawGraph);
    };



    /**
    * This is the AJAX callback function. It splits up the response, converts it to numbers and then creates the chart.
    */
    function DrawGraph (response)
    {
        // The responseText is the output of the AJAX request
        var data = response;

        // Split the data up into an array
        data = data.split(',');

        // Convert the array of strings into an array of numbers
        for (var i=0; i<data.length; ++i) {
            data[i] = Number(data[i]);
        }
        
        // Reset the canvas
        RGraph.Reset(document.getElementById("cvs"));

        // Now draw the chart
        var line = new RGraph.Line({
            id: 'cvs',
            data: data,
            options: {
                textAccessible: true,
                hmargin: 10,
                linewidth: 2,
                ymax: 100,
                labels: ['Gary','Olga','Lewis','Rachel','Nathan','Matt','Kevin','Indigo','Lou','Pete']
            }
        }).draw()
    }
</script>