"chartValueSelected" is not getting called.

[SatishBirajdar]

I did all things asked on http://stackoverflow.com/questions/35038724/tap-callback-on-bar-in-barchart-in-ios-charts . @danielgindi did you do any changes in the library, preventing to detect the Bar tap event? Thanks in advance.

import UIKit
import Charts

class QuarterlyForecastOverviewViewController: UIViewController, ChartViewDelegate {
    
    @IBOutlet weak var barChartView: BarChartView!
    
    var months: [String]!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        months = ["Jan", "Feb", "Mar", "Apr"]
        let unitsSold = [20.0, 4.0, 6.0, 3.0]
        
        setChart(dataPoints: months, values: unitsSold)
        
        barChartView.notifyDataSetChanged()

        barChartView.pinchZoomEnabled = false
        barChartView.dragEnabled = false
        barChartView.setScaleEnabled(false)
        
        barChartView.xAxis.labelPosition = XAxis.LabelPosition.bottom
        barChartView.xAxis.labelTextColor = UIColor.gray
        barChartView.xAxis.axisLineColor = UIColor.white
        barChartView.leftAxis.axisMinValue = 0
        barChartView.leftAxis.axisLineColor = UIColor.red
        barChartView.leftAxis.removeAllLimitLines()
        barChartView.leftAxis.drawZeroLineEnabled = false
        barChartView.leftAxis.drawLimitLinesBehindDataEnabled = true
        barChartView.leftAxis.labelTextColor = UIColor.white
        barChartView.rightAxis.enabled = false
        barChartView.extraBottomOffset = 10.0
        barChartView.extraRightOffset = 10.0
        barChartView.highlightPerTapEnabled = true
        barChartView.drawGridBackgroundEnabled = false
        barChartView.xAxis.drawGridLinesEnabled = false
        barChartView.leftAxis.drawGridLinesEnabled = false
        barChartView.descriptionText = ""
        
        barChartView.xAxis.granularity = 1
        barChartView.xAxis.granularityEnabled = true
        barChartView.xAxis.labelCount = 4
        
        barChartView.delegate = self
    }
    
    func setChart(dataPoints: [String], values: [Double]) {
        
        let formatter = BarChartFormatter()
        formatter.setValues(values: dataPoints)
        let xaxis:XAxis = XAxis()
        
        barChartView.noDataText = "You need to provide data for the chart."
        var dataEntries: [BarChartDataEntry] = []
        
        for i in 0..<dataPoints.count
        {
            let dataEntry = BarChartDataEntry(x: Double(i), y: values[i])
            dataEntries.append(dataEntry)
        }
        
        let chartDataSet = BarChartDataSet(values: dataEntries, label: "Billing Hours")
        
        let chartData = BarChartData(dataSet: chartDataSet)

        xaxis.valueFormatter = formatter
        barChartView.xAxis.labelPosition = .bottom
        barChartView.animate(xAxisDuration: 1.0, yAxisDuration: 1.0, easingOption: .easeInBounce)
        chartDataSet.colors = [UIColor(red: 230/255, green: 126/255, blue: 34/255, alpha: 1)]
        barChartView.xAxis.drawGridLinesEnabled = false
        barChartView.xAxis.valueFormatter = xaxis.valueFormatter
        barChartView.chartDescription?.enabled = false
        barChartView.legend.enabled = true
        barChartView.rightAxis.enabled = false
        barChartView.data = chartData
  
    }
    
    func chartValueSelected(chartView: ChartViewBase, entry: ChartDataEntry, dataSetIndex: Int, highlight: Highlight) {
        print("Bar selected")
    }
    
}


@objc(BarChartFormatter)
public class BarChartFormatter: NSObject, IAxisValueFormatter
{
    var names = [String]()
    
    public func stringForValue(_ value: Double, axis: AxisBase?) -> String
    {
        return names[Int(value)]
    }
    
    public func setValues(values: [String])
    {
        self.names = values
    }
}

[liuxuan30]

This is nothing changed for the delegate. Please debug on your side to give proofs.
Besides, put setChart(dataPoints: months, values: unitsSold) after you set up your chart property like barChartView.xAxis.labelCount = 4. You are changing chart properties after feeding data, which will cause issues such as the highlight.

[SatishBirajdar]

@liuxuan30 Okay, I have re-arranged barChartView.xAxis.labelCount = 4 and setChart(dataPoints: months, values: unitsSold), thanks for the suggestion. But the issue isn't fixed yet.

In ChartViewBase Class -

delegate!.chartValueSelected?(self, entry: entry!, highlight: h!) = nil , but,
delegate = SatishChartsDemo.QuarterlyForecastOverviewViewController

So my concern:

1. why is delegate!.chartValueSelected?(self, entry: entry!, highlight: h!) = nil, since we already have func chartValueSelected defined in QuarterlyForecastOverviewViewController class ?

2. In QuarterlyForecastOverviewViewController, am I defining the function chartValueSelected, correctly?

Thanks in advance.

[thierryH91200]

try

    public func chartValueSelected(_ chartView: ChartViewBase, entry: ChartDataEntry, highlight: Highlight) {
        print("Bar selected")
    }

and not

func chartValueSelected(chartView: ChartViewBase, entry: ChartDataEntry, dataSetIndex: Int, highlight: Highlight) {
    print("Bar selected")
}

[SatishBirajdar]

@thierryH91200 Yes, I tried

    public func chartValueSelected(_ chartView: ChartViewBase, entry: ChartDataEntry, highlight: Highlight) {
        print("Bar selected")
    }

Didn't worked. Can you please provide the link of the sample project in Swift, where function chartValueSelected() is working?

Thanks in advance.

[thierryH91200]

BarChartViewController.swift.zip

[SatishBirajdar]

@thierryH91200 Thanks, this is really helpful. :)

[anoo-radha]

@SatishBirajdar did you get the delegate chartValueSelected to work? I ran into the same problem of the delegate not being called.
Thanks in advance

EDIT: thanx @thierryH91200 . saw that

barChartView.delegate = self

is the answer to cal the delegate function

[SatishBirajdar]

@anoo-radha Try the .zip sample that @thierryH91200 uploaded

[Renish-GlobeSync]

@SatishBirajdar , @danielgindi , @thierryH91200
I have applied all above mentioned steps but it's not working. Please review code on below attached link and let Mme know what I'm missing
https://stackoverflow.com/questions/67197708/chartvalueselected-chartview-chartviewbase-entry-chartdataentry-highlight

[esma01]

Even the sample project is not working! Only the last and middle data points can be selected. For other data points, I see chartValueNothingSelected in the console.

[tolgaytoklar]

Even the sample project is not working! Only the last and middle data points can be selected. For other data points, I see chartValueNothingSelected in the console.

I have the exact same problem

[esma01]

The latest version has a data selection bug. I downgraded to 3.5.0 and the selections work now. @tolgaytoklar

[tolgaytoklar]

The latest version has a data selection bug. I downgraded to 3.5.0 and the selections work now. @tolgaytoklar

Thank you so much, it also works for me now.

[FleetPhil]

Thank you!!! That's been killing me for 2 days - only a few points on the chart caused a call to chartValueSelected. I've reverted to 3.6.0 and it's now working...

[Alain1919]

I've just run into this issue with a line chart and assume it's the same issue, had upgraded from the cocoapod to the Swift Package Manager 4.0.2 and banged my head against the table for several hours trying to find out what was up. Hopefully this is rectified soon!

[trunghvbk]

Hi, is this issue fixed on the stable version? I found chartValueSelected not called still in ver 4.1.

[MorGoren]

Hi. Ver 4.1.1 still has this problem, is there an update for the fix?