ChartsDemo-Swift crashes

[valeriyvan]

ChartsDemo-Swift crashes when in Line Chart in option choose Toggle Data option and then choose, Toggle Cubic option.

[liuxuan30]

That's because you niled out the chartData and then try to unwrap it:

        case .toggleCubic:
            for set in chartView.data!.dataSets as! [LineChartDataSet] {
                set.mode = (set.mode == .cubicBezier) ? .linear : .cubicBezier
            }

@jjatie this is no big deal. But I checked many of the view controllers uses chartView.data!.dataSets, do you have any smart fix for this? Or we have to fix it one by one.

One option would be add a check before each override func optionTapped(_ option: Option), or we have a if let before each for set in chartView.data!.dataSets

[jjatie]

Looks like we'll need to guard each handleOption implementation.

[jjatie]

@liuxuan30 @valeriyvan I've thought about this some more. It's easy to imagine a case where a user wants to temporarily hide a given ChartData. It seems to me that ChartData should have an isEnabled property or something. If isEnabled == false then it's data sets are not drawn.z

Once this implemented, the demos should not be setting the data to nil, but simply toggling chartData.isEnabled

[valeriyvan]

Does it sound like data should’t be optional anymore?

[jjatie]

That's a different discussion, but I've been thinking yes.

[jjatie]

This seems like a corner case and optionality of many properties are changing in 4.0. As we have limited resources to keep making changes for non-critical areas, I am closing this. After 4.0 is released, we will have more time to reevaluate issues like this.