APEX

I'm attempting to create a custom tooltip on chart data hover.

I'm using these as references:

• https://www.oracle.com/webfolder/technetwork/jet/jetCookbook.html?component=chart&demo=tooltip
• https://www.oracle.com/webfolder/technetwork/jet/jsdocs/oj.ojChart.html#tooltip.renderer

I have some code like this:

function (options) {
    options.tooltip = {
        renderer: function (tooltipContext) {
            return {insert:'<h1>test</h1>'};
        }
    }
    return options;
}

and have inserted it into the chart's initialization function. When hovering the data points, I see a console error saying the passed parameter is not a node.

When stepping through with the debugging tools of my browser, I can see that the code in question is part of the chartBundle, and not my code at all. I also tried returning an element I create with document.createElement('div') but got the same error.

Is this a bug in the way that APEX brings in OJ?