@foggy,
As of now, we don’t have a function that is triggered when the render is complete. But given that all dataPoints in chart are rendered at once after calling chart.render() & CanvasJS can render hundreds of thousands of dataPoints in few hundred milliseconds, so you will have no issue calling a function after calling chart.render().
In case you are still facing the issue, can you create JSFiddle reproducing the issue, so that we can look into the code, run it locally to understand the scenario better and help you out?
—
Sanjoy
Team CanvasJS