如何在模型属性含API经纬度计算城市名时完成属性填充？

我正在开发一款简易天气APP，需展示用户城市名（此部分遇到问题）、当前温度、每日最高/最低温、风速、湿度。OpenWeatherMap API提供了除城市名外的所有数据，我难以梳理获取城市名的逻辑流程。

失败尝试 #

• 创建包含天气报告所有属性的WeatherReport模型，其中city为可选属性，需通过逆地理编码（经纬度转地名）计算得到。
• 通过.task从API下载数据并解码到模型（此步骤正常工作）。
• 填充city属性的两次失败尝试：
  • 尝试1：为lat、lon添加didSet属性观察器调用reverseGeocode函数，但因多变量var声明不能有显式getter/setter失败。
  • 尝试2：修改reverseGeocode返回WeatherReport，但因未将其视为异步函数，导致时序问题，视图卡在加载状态。

最终解决方案 #

将reverseGeocode改为异步函数，使用async await处理，解决了数据填充的时序问题，代码如下：

func getCurrentWeather(latitude: CLLocationDegrees, longitude: CLLocationDegrees) async throws -> WeatherReport? {
        do {
            guard let url = URL(string: "https://api.openweathermap.org/data/3.0/onecall?lat=\(latitude)&lon=\(longitude)&exclude=current,minutely,hourly, alerts&appid=19054ace743dfdfd9&units=imperial") else { throw NetworkError.badURL}
            
            let (data, response) = try await URLSession.shared.data(from: url)
            
            guard let response = response as? HTTPURLResponse else { throw NetworkError.badResponse }
            guard response.statusCode >= 200 && response.statusCode < 300 else { throw NetworkError.badStatus }
            
            let decodedData = try JSONDecoder().decode(WeatherReport.self, from: data)
            let decodedDataWithCity = try await decodedData.reverseGeocode()
            return decodedDataWithCity
            
        } catch NetworkError.badURL {
            print("Error creating URL")
        } catch NetworkError.badResponse {
            print("Didn't get a valid response")
        } catch NetworkError.badStatus {
            print("Didn't get a 2xx status code from response")
        } catch {
            print("An error occurred downloading the data")
        }
        
        return nil
    }

func reverseGeocode() async throws -> WeatherReport? {
        let geocoder = CLGeocoder()
        let location = CLLocation(latitude: lat, longitude: lon)
        var report: WeatherReport?
        
        do {
            let placemarks = try await geocoder.reverseGeocodeLocation(location)
            let placemark = placemarks.first
            report = WeatherReport(lat: lat, lon: lon, city: placemark?.locality, timezone: timezone, timezoneOffset: timezoneOffset, daily: daily)
        } catch {
            print("Error: \(error.localizedDescription)")
        }
        
        return report
    }

内容的提问来源于stack exchange，提问作者lolrie