CODEWITHSUNDEEP
iosswiftcharts
Kiran Lim
Kiran Lim

Reputation: 39

Line chart iOS doesn't display chart entries

So I'm creating a fitness app to display a changing variable calories burnt today stored as a Double in User defaults. I want to make it such that every hour, the view controller displaying the line graph would check the User default calories burnt today and add a line chart entry containing the value stored in calories burnt today and display it on the line graph so that the user would be able to monitor his calories burnt throughout the day.

But the problem is that the first time I segue into the viewController, there is a single point present in the line graph showing the number of calories burnt, but when I next segue into the ViewController, the line graph view is blank!

code is below:

import UIKit
import Charts

class DaysViewController: UIViewController, ChartViewDelegate {

    
    @IBOutlet weak var graphsview: UIView!
    var linechart = LineChartView()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        linechart.delegate = self
        
        // Do any additional setup after loading the view.
    }
    override func viewDidLayoutSubviews() {
        linechart.frame = CGRect(x: 0, y: 0, width: self.graphsview.frame.size.width, height: self.graphsview.frame.size.height)
        linechart.center = graphsview.center
        view.addSubview(linechart)
        
        var entries = [ChartDataEntry]()
        let caloriesburnt = UserDefaults.standard.double(forKey: "calories burnt today")
        var hours3 = UserDefaults.standard.integer(forKey: "hoursofexerciserecorded")
        UserDefaults.standard
        let date = Date()
        let calender = Calendar.current
        let currenthour = calender.component(.minute, from: date)
        let previoushour = UserDefaults.standard.integer(forKey: "hour")
        let hour2 = previoushour + 1
        if hour2 <= currenthour {
            hours3 += 1
            entries.append(ChartDataEntry(x: Double(hours3), y: caloriesburnt))
            UserDefaults.standard.set(hours3, forKey: "daysofexerciserecorded")
            UserDefaults.standard.set(currenthour, forKey: "hour")
        }
        
        let set = LineChartDataSet(entries: entries)
        set.colors = ChartColorTemplates.colorful()
        let data = LineChartData(dataSet: set)
        linechart.data = data
    }


    /*
    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        // Get the new view controller using segue.destination.
        // Pass the selected object to the new view controller.
    }
    */

}

Upvotes: 1

Views: 258

Answers (1)

Alastar
Alastar

Reputation: 1374

I'm noticing a lot of errors inside this code.

1st

Why put this line view.addSubview(linechart) inside viewDidLayoutSubviews()?

viewDidLayoutSubviews gets called n times so you are adding n linechart to your view.

2nd

Why do you get dimensions from graphsview and then you add your linechart to your view?

3rd

Remove that UserDefaults.standard not used in your code

Edit (full code)

override func viewDidLoad() {
    super.viewDidLoad()

    linechart.frame = CGRect(x: 0, y: 0, width: yourWidht, height: yourHeight)
    linechart.center = graphsview.center
    graphsview.addSubview(linechart)
    setChartData()
}

private func setChartData() {
    var entries = [ChartDataEntry]()
    let caloriesburnt = UserDefaults.standard.double(forKey: "calories burnt today")
    var hours3 = UserDefaults.standard.integer(forKey: "hoursofexerciserecorded")
    
     let date = Date()
     let calender = Calendar.current
     let currenthour = calender.component(.minute, from: date)
     let previoushour = UserDefaults.standard.integer(forKey: "hour")
     let hour2 = previoushour + 1
     if hour2 <= currenthour {
         hours3 += 1
         entries.append(ChartDataEntry(x: Double(hours3), y: caloriesburnt))
         UserDefaults.standard.set(hours3, forKey: "daysofexerciserecorded")
         UserDefaults.standard.set(currenthour, forKey: "hour")
     }  
     let set = LineChartDataSet(entries: entries)
     set.colors = ChartColorTemplates.colorful()
     let data = LineChartData(dataSet: set)
     linechart.data = data
}

Upvotes: 1

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