BarChartDataSet with only negative values doesn't call stringForValue on formatter

[jonseguin]

Hi !
I have a strange issue when trying to display a BarChartView.
When I make a BarChartDataSet with only negatives y-values, the valueFormatter "stringForValue" never get called. If I set at least one of the value positive, it works.

Here is my code (with an example of data) :

let dataSet = BarChartDataSet(values: [BarChartDataEntry(x:0, y:-4),
                                         BarChartDataEntry(x:1, y:-7),
                                         BarChartDataEntry(x:2, y:-10)], label: "")
barChartView.data = BarChartData(dataSet: dataSet) 
barChartView.data?.setValueFormatter(MyValueFormatter())

barChartView.pinchZoomEnabled = false
barChartView.dragEnabled = false
barChartView.setScaleEnabled(false)
barChartView.drawValueAboveBarEnabled = true
barChartView.drawBarShadowEnabled = false
barChartView.xAxis.enabled = false
barChartView.leftAxis.enabled = false
barChartView.rightAxis.enabled = false
barChartView.legend.enabled = false
barChartView.chartDescription = nil

class MyValueFormatter : NSObject, IValueFormatter {
    func stringForValue(_ value: Double, entry: ChartDataEntry, dataSetIndex: Int, viewPortHandler: ViewPortHandler?) -> String {
        return String(value)
    }
} 

Replace BarChartDataEntry(x:0, y:-4) by BarChartDataEntry(x:0, y:4), and the stringForValue is called.
Here, I set my custom IValueFormatter, but the issue also exist if I let the default one.

Am I missing a configuration property ?

[liuxuan30]

take a look and debug at open override func drawValues(context: CGContext)() where it will call stringForValue(), check the if conditions

[jonseguin]

Ok so it works now.
I am including the framework using Carthage, and it seems I just forgot to add the frameworks to the "Linked frameworks and librairies" on my project target.
It is weird that it is the only issue, since I used this framework a lot in this project.
Thanks !