User Story

As an end-user, I want to drag a point with the mouse to change its value and the series data at the server-side alto changes accordingly.

Acceptance Criteria

An application developer can listen to dragging events and decide how to update the corresponding point in a series, for example, he can convert it to an approximate value and save it into the series.

Details

• Currently, we can enable dragging by chart.getSeries().getDragDrop().setDraggableY(true);. But it just a client-side effect, and doesn't update to the server.
• jfreechart supports a similar feature
  
• related highcharts callback: https://api.highcharts.com/highcharts/plotOptions.series.point.events.drag