WeatherKit HourWeather precipitationAmount

Question

Created Jun ’22

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I'm trying to access this element of the HourWeather retrieved from a call to weatherService. When I print in the debugger what is received, it's clear that there is an element there called precipitationAmount. Here is an example of everything retrieved in HourWeather for a particular hour:

HourWeather(date: 2022-06-12 22:00:00 +0000, cloudCover: 0.46, condition: Breezy, symbolName: "wind", dewPoint: 9.12 °C, humidity: 0.71, isDaylight: true, precipitation: rain, precipitationChance: 0.23, precipitationAmount: 0.21 mm, snowfallAmount: 0.0 mm, pressure: 997.65 mbar, pressureTrend: Rising, temperature: 14.34 °C, apparentTemperature: 13.74 °C, uvIndex: WeatherKit.UVIndex(value: 1, category: Low), visibility: 25915.82 m, wind: WeatherKit.Wind(compassDirection: Northwest, direction: 304.0 °, speed: 29.47 km/h, gust: Optional(41.56 km/h)))

But when I try to access that element as part of a SwiftUI view in Xcode (14.0 beta), I get this error:

 Value of type 'HourWeather' has no member 'precipitationAmount'

Furthermore, that element is not listed as part of the documentation at https://developer.apple.com/documentation/weatherkit/hourweather, which is presumably the reason for the Xcode error.

But it's there in what is retrieved, so how can I access it?

Forgive me if this is a noob question - I'm not an expert SwiftUI programmer.

Thanks ... Neil

Answered by acorscadden in 719586022

woot! Looks like with got precipitationAmount in beta 3 :)

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Answer 1

tehoro OP

Jun ’22

Incidentally, the WeatherKit REST API includes "precipitationAmount" for hourly weather conditions:

https://developer.apple.com/documentation/weatherkitrestapi/hourweatherconditions

so it seems odd and inconsistent that it is not included in the Structure definition for HourWeather:

https://developer.apple.com/documentation/weatherkit/hourweather

0

Answer 2

tehoro OP

Jun ’22

So I've solved my own issue for now. It may not be pretty (haven't used strings much), but by defining this function I was able to extract the precipitation amount as a Measurement, just like other elements of the HourWeather struct.

// Function to get precipitationAmount as a measurement from one instance of HourWeather
// Written by Neil Gordon, 14 June 2022 - pending inclusion of precipitationAmount in the
// WeatherKit definition of the Structure for HourWeather

func precipitationAmount(hourWeatherElement: HourWeather) -> Measurement<UnitLength> {
    var contents : String = " "
    var answer = Measurement(value: -9.9, unit: UnitLength.millimeters)  // Default if problems

    print (hourWeatherElement, to: &contents)    // Get the contents of the instance as a string

    if let firstRange = contents.range(of: "precipitationAmount: ") {     // Find where precip amount should be
        let startIndex = firstRange.upperBound
        // Drop everything before that
        contents = String(contents[startIndex...])

        // Find position of first comma, then use up to just before that
        let commaIndex = contents.firstIndex(of: ",")!

        // Get the two bits of value and units - usually looks something like "2.3 mm"
        let contents = contents[..<commaIndex]
        let bits = contents.components(separatedBy: " ")

        // Convert string to a Double for use in Measurement

        if let amount = Double(bits[0])  {
            let units = bits[1]

           // I think mm and in are all I should see?

            if units == "mm" {
                 answer = Measurement(value: amount, unit: UnitLength.millimeters)
            } else {
                 answer = Measurement(value: amount, unit: UnitLength.inches)
            }
        }
    }
    return answer
}

2

Answer 3

acorscadden OP

Jul ’22

Accepted Answer

woot! Looks like with got precipitationAmount in beta 3 :)

0