SwiftUI and CoreData: Horizontal bar chart with different coloured values - swift

Question

I am learning SwiftUI with CoreData and I have that one demo app where I am stuck.
Outcome:
I would like to present different coloured bar charts based on numeral values (calories). I managed to present numeral values with one colour, but not different colours based on value.
Here is image about desired outcome and my Swift code.
Thank you for any help! -Toni
Desired UI outcome
Code screenshot
import SwiftUI
struct ColourChart: View {
#Environment(\.managedObjectContext) var managedObjContext
#State private var name = ""
#State private var calories: Double = 0
#State private var color: Color = .gray
#FetchRequest(sortDescriptors: [SortDescriptor(\.calories)]) var food: FetchedResults<CaloriesEntity>
var body: some View {
List {
ForEach(food) { food in
VStack(alignment: .leading) {
HStack(alignment: .top) {
Text(food.name ?? "Unknown name")
.onAppear {
calories = food.calories
name = food.name!
}
Spacer()
Text(calcTimeSince(date:food.date!))
.foregroundColor(.gray)
.font(.caption)
.italic()
}///-HStack
ZStack {
Rectangle()
.foregroundColor(ColouredBars())
.frame(width: food.calories/3, height: 15, alignment: .trailing)
.cornerRadius(5)
Text("\(Int(food.calories))")
.foregroundColor(.white)
.font(.caption)
}///-ZStack
}///-VStack
}///ForEach Ends
}///-List
}///-View
func ColouredBars() -> Color {
let calories: Double = 299
if calories > 600 {
color = .red
} else if calories > 300 {
color = .yellow
} else {
color = .green
}
return color
}
}///-Struct
struct ColourChart_Previews: PreviewProvider {
static var previews: some View {
ColourChart()
}
}

Answer 1

You would want to add a calories parameter and change the return type to color. The code would look something like this:
func calorieColor(calorie: Double) -> Color {
if calorie >= 600 {
return .red
} else if calorie >= 300 {
return .yellow
} else {
return .green
}
return .clear
}
the .clear is there just to allow the function to return some type of color if the if statement isn't applicable but that shouldn't be the case.
You could also do func calorieColor(_ calorie: Double) -> Color { The _ allows you to make the code a little more concise by allowing you to just type calorieColor(150) vs calorieColor(Calorie: 150).