Question

You can ask the user to supply data by clicking to adding points to a char, see this demo.
But I don’t know how to retrieve those points and send them back to the server (with a POST or AJAX, whatever). I just want to know how to get them in javascript.

Answer 1

Just access the chart variable defined like this in javascript:

<!-- 2. Add the JavaScript to initialize the chart on document ready -->
<script type="text/javascript">
    var chart;
    $(document).ready(function() {
        chart = new Highcharts.Chart({
            ...
        });         
    });
</script>

Access the new points like this:

<script type="text/javascript">
    function printObject(o) {
        var out = '';
        for (var p in o) {
            out += p + ': ' + o[p] + '\n';
        }
        alert(out);
    }

    $("#clickme").click(function() {
        for (var i = 0; i < chart.series[0].data.length; i++) {
            printObject(chart.series[0].data[i]);
        }
    });
</script>