I have chart that shows the temperature data of a bunch of showers. The DataSource that supplies this data groups the data by the ShowerId. The problem occurs when none of the checkboxes are checked (no data will be shown). The DataSource will hence return no data and the Chart._onDataChanged will crash on the line:
categoriesData = grouped ? data.items : data
I have temporarly solved this by overwriting the line in the _dataChangeHandler/_onDataChanged to
categoriesData = grouped && typeof data === "object" ? data.items : data
It's not the best solution, but it gets the job done for my situation. I have had similar problems with empty grouped datasources in the past, so I wonder if you could possibly provide a fix in a future update which will still create the grouped objects (even if received data array is empty), but just with an empty items array and value? Or is there a certain reason these are not created if no data is received?