Problem with how to implement distance conversion - ios

Question

I'm trying to make a basic distance conversion app, and my solution is to convert the user input to meters first before converting it to their desired unit. However, I don't know how to implement it. How would I go about that?
struct ContentView: View {
#State private var inputNumber = ""
#State private var inputUnit = 0
#State private var outputUnit = 1
let inputUnits = ["Meters", "Kilometers", "Feet", "Yard", "Miles"]
let outputUnits = ["Meters", "Kilometers", "Feet", "Yard", "Miles"]
var conversions: Double {
//conversions computed here
}
var body: some View {
NavigationView {
Form {
Section {
TextField("Enter measurement", text: $inputNumber)
.keyboardType(.numberPad)
Picker("Your unit", selection: $inputUnit) {
ForEach(0 ..< inputUnits.count) {
Text("\(self.inputUnits[$0])")
}
}
}
Section(header: Text("What unit would you like to convert to?")) {
Picker("Convert to...", selection: $outputUnit) {
ForEach(0 ..< outputUnits.count) {
Text("\(self.outputUnits[$0])")
}
}
}
Section {
Text("\(meterToKM)")
}
}
.navigationBarTitle("How Far?")
}
}
}

Answer 1

You can do the conversion in a method, say calculateConvertedValue and invoke it in a button within your section and make changes to an #State property say convertedValue which then displays the final value in your Text View component. Here's an example:
struct ContentView: View {
#State private var inputNumber = ""
#State private var inputUnit = 0
#State private var outputUnit = 1
#State private var convertedValue = ""
let inputUnits = ["Meters", "Kilometers", "Feet", "Yard", "Miles"]
let outputUnits = ["Meters", "Kilometers", "Feet", "Yard", "Miles"]
var body: some View {
NavigationView {
Form {
Section {
TextField("Enter measurement", text: $inputNumber)
.keyboardType(.numberPad)
Picker("Your unit", selection: $inputUnit) {
ForEach(0 ..< inputUnits.count) {
Text("\(self.inputUnits[$0])")
}
}
}
Section(header: Text("What unit would you like to convert to?")) {
Picker("Convert to...", selection: $outputUnit) {
ForEach(0 ..< outputUnits.count) {
Text("\(self.outputUnits[$0])")
}
}
}
Section {
Button(action: {
self.calculateConversion()
}) { Text("Convert") }
Text(convertedValue)
}
}
.navigationBarTitle("How Far?")
}
}
func calculateConvertedValue() {
convertedValue = "New converted value."
}
}