在字典中解码字典 - JSON/Swift

Question

我有一个 JSON 文件，其结构如下：

"forecast": [
    {
      "altimeter": "",
      "clouds": [
        {
          "repr": "OVC025",
          "type": "OVC",
          "altitude": 25,
          "modifier": null,
          "direction": null
        }
      ],
      "flight_rules": "MVFR",
      "other": [],
      "sanitized": "0318/0424 34017G26KT P6SM -RA OVC025",
      "visibility": {
        "repr": "P6",
        "value": null,
        "spoken": "greater than six"
      },
      "wind_direction": {
        "repr": "340",
        "value": 340,
        "spoken": "three four zero"
      }

And so on....

我正在尝试使用 DispatchQueue 访问信息并更新 UI，但无法弄清楚如何从 forecast: clouds: repr（或任何其他类似的嵌套）中提取数据。我可以成功地提取数据，例如：forecast: raw。我尝试了第一个没有嵌套的结构，但是没有用（正如预期的那样，数据是里面的另一个索引）。

我的解码文件是：

//
//  TAFData.swift
//  AvWx Pro
//
//  Created by Grayson Bertaina on 9/24/20.
//

import Foundation

struct TAFDatas: Codable {
   
    
    let flight_rules: String?
    let time: TimeTAF?
    let station: String?
    let raw: String?
    let forecast: [ForecastTAF?]
    let end_time: ?
    let wind_gust: ?
}

struct ForecastTAF: Codable {
    let raw: String?
    struct CloudsTAF: Codable {
        let type: String
        let altitude: Int
    }
    struct endTimeTAF: Codable {
        let repr: String
    }

    struct WindSpeedTAF: Codable {
        let value: Int
    }

    struct WindGustTAF: Codable {
        let value: Int
    }

    struct WindDirectionTAF: Codable {
        let repr: String
    }

    struct VisibilityTAF: Codable {
        let repr: String
    }

    struct WxcodesTAF: Codable {
        let value: String
    }

    struct StartTimeTAF: Codable {
        let repr: String
    }

    struct EndTimeTAF: Codable {
        let repr: String
    }


    
}

struct TimeTAF: Codable {
    let repr: String
}

我的解析文件是：

//
//  TAFManager.swift
//  AvWx Pro
//
//  Created by Grayson Bertaina on 9/24/20.
//

import Foundation

protocol TAFManagerDelegate : class {
    func didUpdateTAF(_ weatherManager: TAFManager, weatherTAF: TAFModel)
    func didFailWithErrorTAF(error: Error)
}



struct TAFManager {
    let TAFURL = "https://avwx.rest/api/taf/"
    
    weak var delegate : TAFManagerDelegate?

    func fetchWeatherTAF (stationICAO: String) {
        let TAFurlString = "\(TAFURL)\(stationICAO)?token=OVi45FiTDo1LmyodShfOfoizNe5m9wyuO6Mkc95AN-c"
        performRequestTAF(with: TAFurlString)
    }
    
    func performRequestTAF (with TAFurlString: String) {
        if let TAFurl = URL(string: TAFurlString) {
            let session = URLSession(configuration: .default)
                
            
            let taskTAF = session.dataTask(with: TAFurl) { (data, response, error) in
                if error != nil {
                    self.delegate?.didFailWithErrorTAF(error: error!)
                    return
                }
                
                if let safeDataTAF = data {
                    if let weatherTAF = self.parseJSONTAF(safeDataTAF) {
                        self.delegate?.didUpdateTAF(self, weatherTAF: weatherTAF)
                    }
                }
            }
            
            taskTAF.resume()
            print(TAFurlString)
            
            
            }
        }
    
   
    func parseJSONTAF(_ TAFData: Data) -> TAFModel? {
        
        
        do {
            let decoderTAF = JSONDecoder()
            let decodedDataTAF = try decoderTAF.decode(TAFDatas.self, from: TAFData)
            
            
            
            let cloudsTAF = decodedDataTAF.clouds
            let wxcodesTAF = decodedDataTAF.wx_codes
            let forecastTAF = decodedDataTAF.forecast
            let lowCloudsTypeTAF = (cloudsTAF.count > 0 ? cloudsTAF[0]?.type : nil) ?? "N/A"
            let midCloudsTypeTAF = (cloudsTAF.count > 1 ? cloudsTAF[1]?.type : nil) ?? "N/A"
            let highCloudsTypeTAF = (cloudsTAF.count > 2 ? cloudsTAF[2]?.type : nil) ?? "N/A"
            let lowCloudsAltTAF = (cloudsTAF.count > 0 ? cloudsTAF[0]?.altitude : nil) ?? 0
            let midCloudsAltTAF = (cloudsTAF.count > 1 ? cloudsTAF[1]?.altitude : nil) ?? 0
            let highCloudsAltTAF = (cloudsTAF.count > 2 ? cloudsTAF[2]?.altitude : nil) ?? 0
            let reportingStationVarTAF = decodedDataTAF.station ?? "N/A"
            let windGustValueTAF = decodedDataTAF.wind_gust?.value ?? 0
            let windSpeedValueTAF = decodedDataTAF.wind_speed?.value ?? 0
            let windDirectionValueTAF = decodedDataTAF.wind_direction?.repr ?? "N/A"
            let visibilityValueTAF = decodedDataTAF.visibility?.repr ?? "N/A"
            let flightRulesValueTAF = decodedDataTAF.flight_rules ?? "N/A"
            let timeReportedTAF = decodedDataTAF.time?.repr ?? "N/A"
            let firstWxCode1TAF = (wxcodesTAF.count > 0 ? wxcodesTAF[0]?.value : "N/A") ?? "N/A"
            let startTimeTaf = decodedDataTAF.start_time?.repr ?? "N/A"
            let endTimeTaf = (forecastTAF.count > 0 ? forecastTAF[0]? : nil) ?? "N/A"
            let rawTAFData = (forecastTAF.count > 0 ? forecastTAF[0]?.raw : nil) ?? "N/A"
            
            
            let weatherTAF = TAFModel(lowestCloudsTypeTAF: lowCloudsTypeTAF , lowestCloudsAltTAF: lowCloudsAltTAF, middleCloudsTypeTAF: midCloudsTypeTAF , middleCloudsAltTAF: midCloudsAltTAF, highestCloudsTypeTAF: highCloudsTypeTAF , highestCloudsAltTAF: highCloudsAltTAF, reportingStationTAF: reportingStationVarTAF, windGustTAF: windGustValueTAF, windSpeedTAF: windSpeedValueTAF, windDirectionTAF: windDirectionValueTAF, visibilityTAF: visibilityValueTAF, flightRulesTAF: flightRulesValueTAF, timeTAF: timeReportedTAF, startTimeTAF: startTimeTaf, endTimeTAF: endTimeTaf, firstWxCodeTAF: firstWxCode1TAF, rawTAF: rawTAFData)
            
            delegate?.didUpdateTAF(self, weatherTAF: weatherTAF)
            return weatherTAF
            
        } catch {
            delegate?.didFailWithErrorTAF(error: error)
            return nil
        }
    }
    
    

}

我的模型文件是：

//
//  WeatherModel.swift
//  AvWx Pro
//
//  Created by Grayson Bertaina on 9/22/20.
//

import Foundation

struct WeatherModel {
    
    
    let lowestCloudsType: String
    let lowestCloudsAlt: Int
    let middleCloudsType: String
    let middleCloudsAlt: Int
    let highestCloudsType: String
    let highestCloudsAlt: Int
    let reportingStation: String
    let windGust: Int
    let windSpeed: Int
    let windDirection: String
    let visibility: String
    let flightRules: String
    let time: String
    let remarks: String
    let altimeter: Double
    let temperature: String
    let dewpoint: String
    let firstWxCode: String
    
    var altToString1: String {
        return String(format: "%u" + "00 ft", lowestCloudsAlt)
    }
    
    var altToString2: String {
        return String(format: "%u" + "00 ft", middleCloudsAlt)
    }
    
    var altToString3: String {
        return String(format: "%u" + "00 ft", highestCloudsAlt)
    }
    
    var windGustString: String {
        return String(format: "%u" + "kt", windGust)
    }
    
    
    var windSpeedString: String {
        return String(format: "%u" + "kt", windSpeed)
    }
    
    var altimeterString: String {
        return String(format: "%.2f" + " inHg", altimeter as CVarArg)
    }
    
    var visUnits: String {
        return visibility + " SM"
    }
    
    var degUnits: String {
        return windDirection + "°"
    }
    
    var tempUnits: String {
        return temperature + "°C"
    }
    
    var dewUnits: String {
        return dewpoint + "°C"
    }

    
    var flightConditions: String {
        switch flightRules {
        case "VFR":
            return "green"
        case "MVFR":
            return "blue"
        case "IFR":
            return "red"
        case "LIFR":
            return "purple"
        default:
            return "gray"
        
        }
    }
}

我认为主要的障碍是获取那些数据密钥。一旦我到了那里，希望其余的一切都会到位。非常感谢您的提前帮助，祝您今天愉快！

有评论，我的新人JSON

// MARK: - TAFData
struct TAFData: Codable {
    let meta: MetaTAF?
    let raw, station: String?
    let time: TimeTAF?
    let remarks: String?
    let forecast: [ForecastTAF?]
    let startTime, endTime: TimeTAF?
    let maxTemp, minTemp: String?
    let alts, temps: JSONNull?

    enum CodingKeys: String, CodingKey {
        case meta, raw, station, time, remarks, forecast
        case startTime = "start_time"
        case endTime = "end_time"
        case maxTemp = "max_temp"
        case minTemp = "min_temp"
        case alts, temps, units
    }
}

// MARK: - Time
struct TimeTAF: Codable {
    let repr, dt: String
}

// MARK: - Forecast
struct ForecastTAF: Codable {
    let altimeter: String
    let clouds: [CloudTAF]
    let flightRules: String
    let other: [JSONAny]
    let sanitized: String
    let visibility, windDirection: VisibilityTAF
    let windGust: VisibilityTAF?
    let windSpeed: VisibilityTAF
    let wxCodes: [WxCodeTAF]
    let endTime: TimeTAF
    let icing: [JSONAny]
    let probability: JSONNull?
    let raw: String
    let startTime: TimeTAF
    let turbulence: [JSONAny]
    let type: String
    let windShear: JSONNull?
    let summary: String

    enum CodingKeys: String, CodingKey {
        case altimeter, clouds
        case flightRules = "flight_rules"
        case other, sanitized, visibility
        case windDirection = "wind_direction"
        case windGust = "wind_gust"
        case windSpeed = "wind_speed"
        case wxCodes = "wx_codes"
        case endTime = "end_time"
        case icing, probability, raw
        case startTime = "start_time"
        case turbulence, type
        case windShear = "wind_shear"
        case summary
    }
}

// MARK: - Cloud
struct CloudTAF: Codable {
    let repr, type: String
    let altitude: Int
    let modifier, direction: JSONNull?
}

// MARK: - Visibility
struct VisibilityTAF: Codable {
    let repr: String
    let value: Int?
    let spoken: String
}

// MARK: - WxCode
struct WxCodeTAF: Codable {
    let repr, value: String
}

// MARK: - Meta
struct MetaTAF: Codable {
    let timestamp: String
}

// MARK: - Units
struct UnitsTAF: Codable {
    let altimeter, altitude, temperature, visibility: String
    let windSpeed: String

    enum CodingKeys: String, CodingKey {
        case altimeter, altitude, temperature, visibility
        case windSpeed = "wind_speed"
    }
}

// MARK: - Encode/decode helpers

class JSONNull: Codable, Hashable {

    public static func == (lhs: JSONNull, rhs: JSONNull) -> Bool {
        return true
    }

    public var hashValue: Int {
        return 0
    }

    public func hash(into hasher: inout Hasher) {
        // No-op
    }

    public init() {}

    public required init(from decoder: Decoder) throws {
        let container = try decoder.singleValueContainer()
        if !container.decodeNil() {
            throw DecodingError.typeMismatch(JSONNull.self, DecodingError.Context(codingPath: decoder.codingPath, debugDescription: "Wrong type for JSONNull"))
        }
    }

    public func encode(to encoder: Encoder) throws {
        var container = encoder.singleValueContainer()
        try container.encodeNil()
    }
}

class JSONCodingKey: CodingKey {
    let key: String

    required init?(intValue: Int) {
        return nil
    }

    required init?(stringValue: String) {
        key = stringValue
    }

    var intValue: Int? {
        return nil
    }

    var stringValue: String {
        return key
    }
}

class JSONAny: Codable {

    let value: Any

    static func decodingError(forCodingPath codingPath: [CodingKey]) -> DecodingError {
        let context = DecodingError.Context(codingPath: codingPath, debugDescription: "Cannot decode JSONAny")
        return DecodingError.typeMismatch(JSONAny.self, context)
    }

    static func encodingError(forValue value: Any, codingPath: [CodingKey]) -> EncodingError {
        let context = EncodingError.Context(codingPath: codingPath, debugDescription: "Cannot encode JSONAny")
        return EncodingError.invalidValue(value, context)
    }

    static func decode(from container: SingleValueDecodingContainer) throws -> Any {
        if let value = try? container.decode(Bool.self) {
            return value
        }
        if let value = try? container.decode(Int64.self) {
            return value
        }
        if let value = try? container.decode(Double.self) {
            return value
        }
        if let value = try? container.decode(String.self) {
            return value
        }
        if container.decodeNil() {
            return JSONNull()
        }
        throw decodingError(forCodingPath: container.codingPath)
    }

    static func decode(from container: inout UnkeyedDecodingContainer) throws -> Any {
        if let value = try? container.decode(Bool.self) {
            return value
        }
        if let value = try? container.decode(Int64.self) {
            return value
        }
        if let value = try? container.decode(Double.self) {
            return value
        }
        if let value = try? container.decode(String.self) {
            return value
        }
        if let value = try? container.decodeNil() {
            if value {
                return JSONNull()
            }
        }
        if var container = try? container.nestedUnkeyedContainer() {
            return try decodeArray(from: &container)
        }
        if var container = try? container.nestedContainer(keyedBy: JSONCodingKey.self) {
            return try decodeDictionary(from: &container)
        }
        throw decodingError(forCodingPath: container.codingPath)
    }

    static func decode(from container: inout KeyedDecodingContainer<JSONCodingKey>, forKey key: JSONCodingKey) throws -> Any {
        if let value = try? container.decode(Bool.self, forKey: key) {
            return value
        }
        if let value = try? container.decode(Int64.self, forKey: key) {
            return value
        }
        if let value = try? container.decode(Double.self, forKey: key) {
            return value
        }
        if let value = try? container.decode(String.self, forKey: key) {
            return value
        }
        if let value = try? container.decodeNil(forKey: key) {
            if value {
                return JSONNull()
            }
        }
        if var container = try? container.nestedUnkeyedContainer(forKey: key) {
            return try decodeArray(from: &container)
        }
        if var container = try? container.nestedContainer(keyedBy: JSONCodingKey.self, forKey: key) {
            return try decodeDictionary(from: &container)
        }
        throw decodingError(forCodingPath: container.codingPath)
    }

    static func decodeArray(from container: inout UnkeyedDecodingContainer) throws -> [Any] {
        var arr: [Any] = []
        while !container.isAtEnd {
            let value = try decode(from: &container)
            arr.append(value)
        }
        return arr
    }

    static func decodeDictionary(from container: inout KeyedDecodingContainer<JSONCodingKey>) throws -> [String: Any] {
        var dict = [String: Any]()
        for key in container.allKeys {
            let value = try decode(from: &container, forKey: key)
            dict[key.stringValue] = value
        }
        return dict
    }

    static func encode(to container: inout UnkeyedEncodingContainer, array: [Any]) throws {
        for value in array {
            if let value = value as? Bool {
                try container.encode(value)
            } else if let value = value as? Int64 {
                try container.encode(value)
            } else if let value = value as? Double {
                try container.encode(value)
            } else if let value = value as? String {
                try container.encode(value)
            } else if value is JSONNull {
                try container.encodeNil()
            } else if let value = value as? [Any] {
                var container = container.nestedUnkeyedContainer()
                try encode(to: &container, array: value)
            } else if let value = value as? [String: Any] {
                var container = container.nestedContainer(keyedBy: JSONCodingKey.self)
                try encode(to: &container, dictionary: value)
            } else {
                throw encodingError(forValue: value, codingPath: container.codingPath)
            }
        }
    }

    static func encode(to container: inout KeyedEncodingContainer<JSONCodingKey>, dictionary: [String: Any]) throws {
        for (key, value) in dictionary {
            let key = JSONCodingKey(stringValue: key)!
            if let value = value as? Bool {
                try container.encode(value, forKey: key)
            } else if let value = value as? Int64 {
                try container.encode(value, forKey: key)
            } else if let value = value as? Double {
                try container.encode(value, forKey: key)
            } else if let value = value as? String {
                try container.encode(value, forKey: key)
            } else if value is JSONNull {
                try container.encodeNil(forKey: key)
            } else if let value = value as? [Any] {
                var container = container.nestedUnkeyedContainer(forKey: key)
                try encode(to: &container, array: value)
            } else if let value = value as? [String: Any] {
                var container = container.nestedContainer(keyedBy: JSONCodingKey.self, forKey: key)
                try encode(to: &container, dictionary: value)
            } else {
                throw encodingError(forValue: value, codingPath: container.codingPath)
            }
        }
    }

    static func encode(to container: inout SingleValueEncodingContainer, value: Any) throws {
        if let value = value as? Bool {
            try container.encode(value)
        } else if let value = value as? Int64 {
            try container.encode(value)
        } else if let value = value as? Double {
            try container.encode(value)
        } else if let value = value as? String {
            try container.encode(value)
        } else if value is JSONNull {
            try container.encodeNil()
        } else {
            throw encodingError(forValue: value, codingPath: container.codingPath)
        }
    }

    public required init(from decoder: Decoder) throws {
        if var arrayContainer = try? decoder.unkeyedContainer() {
            self.value = try JSONAny.decodeArray(from: &arrayContainer)
        } else if var container = try? decoder.container(keyedBy: JSONCodingKey.self) {
            self.value = try JSONAny.decodeDictionary(from: &container)
        } else {
            let container = try decoder.singleValueContainer()
            self.value = try JSONAny.decode(from: container)
        }
    }

    public func encode(to encoder: Encoder) throws {
        if let arr = self.value as? [Any] {
            var container = encoder.unkeyedContainer()
            try JSONAny.encode(to: &container, array: arr)
        } else if let dict = self.value as? [String: Any] {
            var container = encoder.container(keyedBy: JSONCodingKey.self)
            try JSONAny.encode(to: &container, dictionary: dict)
        } else {
            var container = encoder.singleValueContainer()
            try JSONAny.encode(to: &container, value: self.value)
        }
    }
}

Answer 1

我可能会使用不同的模型，因为您当前的模型不支持与 JSON:

相同的格式


struct Forecast: Codable {
    let altimeter: String
    let clouds: [Cloud]
    let flightRules: String
    let other: [JSONAny]
    let sanitized: String
    let visibility, windDirection: Visibility

    enum CodingKeys: String, CodingKey {
        case altimeter, clouds
        case flightRules = "flight_rules"
        case other, sanitized, visibility
        case windDirection = "wind_direction"
    }
}

// MARK: - Cloud
struct Cloud: Codable {
    let repr, type: String
    let altitude: Int
}

// MARK: - Visibility
struct Visibility: Codable {
    let repr: String
    let value: Int?
    let spoken: String
}

这样你就可以使用：

if let cloud = forecast.clouds.first() {
    let repr = cloud.repr
    .. Your logic 
}

我的模型中可能缺少一些东西，但你应该有一个想法

在字典中解码字典 - JSON/Swift

Decoding a Dictionary Inside a Dictionary - JSON/Swift

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