Generic input field for any numerical value with the associated unit

Question

Created Jun ’22

Replies 2

Boosts 0

Participants 2

Target: Generic input field for any numerical value with the associated unit. The metadata for this input field is stored in a database and includes:

What the value should represent (text).
Which unit applies to it (text)

For this I try to write the following function:

 func getMeasurment(value: Double, unit: String) -> Measurement<Unit> {
        switch(unit) {

        case "UnitArea.squareKilometers":

            let result = Measurement(value: value, unit: UnitArea.squareKilometers)

            return result

        case "...":

                ....

        }

Of course I get a compiler error, is there a possible solution for this task?

Please excuse my question, but I am absolute beginner in Swift ...

Boost

Answer 1

Claude31 OP

Jun ’22

Replace with UnitArea:

func getMeasurment(value: Double, unit: String) -> Measurement<UnitArea> { }

0

Answer 2

Merlin52 OP

Jun ’22

Thank you for your feedback. Unfortunately, this does not solve my problem. The function is supposed to be applicable for all possible (like UnitArea, UnitAcceleration, UnitAngle, ...). I wrote the following function which returns me the desired result as string.

func showMeasurement(value: Double, unit: String, symbol: Bool) -> String {

        switch(unit) {
            //MARK: Aceleration

        case "UnitAcceleration.metersPerSecondSquared":

            let newValue = Measurement(value: value, unit: UnitAcceleration.metersPerSecondSquared)

            if symbol {

                return newValue.unit.symbol

            } else {

                return newValue.formatted(.measurement(width: .narrow, usage: .asProvided, numberFormatStyle: .number.precision(.fractionLength(2))))

            }



        case "UnitAcceleration.UnitAcceleration":

            let newValue = Measurement(value: value, unit: UnitAcceleration.baseUnit())

            if symbol {

                return newValue.unit.symbol

            } else {

                return newValue.formatted(.measurement(width: .narrow, usage: .asProvided, numberFormatStyle: .number.precision(.fractionLength(2))))

            }
  ....

But later I will also need the corresponding Measurment to be able to calculate with the values.

0