Accepted answer

Got the answer I was looking for; It was a bug in highcharts, fixed here


I am not really familiar with Prototype framework, but I did some tests and look at this code:

function getGraphSVG(options) {
    var svg;
    if (window.charts) {
        window.charts.each(function(pair) {
            svg = pair.value.getSVG(options);
            throw $break;

    return svg;

Somehow this each method returns 2 objects, one being undefined. So do the simple check:

if (pair.value)
     svg = pair.value.getSVG(options);

or in one line

pair.value && ( svg = pair.value.getSVG(options) );

and it should work.

Related Query

More Query from same tag