SwiftUI - 如何使用動態密鑰訪問 API 響應數據？

Question

我在這里先向您的幫助表示感謝。
我第一次在 SwiftUI 中處理 API 調用。 我通過使用 structs/decodable 取回了一部分數據。 我使用枚舉來訪問每一層。 但是，我正在使用的 API 使用當前日期作為鍵，並且我正在努力在不使用字符串文字的情況下訪問該層數據。 有任何想法嗎？
這就是我所擁有的。

struct NEObjects: Decodable {
    let fromToday: [NEObject]
    
    enum CodingKeys: String, CodingKey {
        case  fromToday = "2021-02-16"
    }
}

我將當前日期存儲在用戶默認值中。 但是如果我做類似的事情

let date = UserDefaults.standard.string(forKey: "current_date")
case fromToday = date

然后我收到一條錯誤消息“枚舉大小寫的原始值必須是文字”
我不確定我還能如何訪問這一層，因為我是 swiftUI 的新手。
以下是完整數據 model 供參考：

import Foundation

let date = UserDefaults.standard.string(forKey: "current_date")

struct NEOData: Decodable  {
    let elementCount: Int
    let neObjects: NEObjects
    
    enum CodingKeys: String, CodingKey {
        case elementCount = "element_count"
        case neObjects = "near_earth_objects"
    }
}

struct NEObjects: Decodable {
    let fromToday: [NEObject]
    
    enum CodingKeys: String, CodingKey {
        case  fromToday = "2021-02-15"
    }
}

struct NEObject: Decodable {
    let name: String
    let absoluteMagnitude: Double
    let diameter: Diameter
    let isHazardous: Bool
    let closeApproachData: [CloseApproachData]
    let isSentry: Bool
    
    enum CodingKeys: String, CodingKey {
        case name = "name"
        case absoluteMagnitude = "absolute_magnitude_h"
        case diameter = "estimated_diameter"
        case isHazardous = "is_potentially_hazardous_asteroid"
        case closeApproachData = "close_approach_data"
        case isSentry = "is_sentry_object"
    }
}

struct Diameter: Decodable {
    let kilometers: Kilometers
    let meters: Meters
    let miles: Miles
    let feet: Feet
}

struct CloseApproachData: Decodable {
    let velocity: Velocity
    let missDistance: MissDistance
    let date: String
    
    enum CodingKeys: String, CodingKey {
        case velocity = "relative_velocity"
        case missDistance = "miss_distance"
        case date = "close_approach_date"
    }
}

struct Velocity: Decodable {
    let mph: String
    let kph: String
    
    enum CodingKeys: String, CodingKey {
        case mph = "miles_per_hour"
        case kph = "kilometers_per_hour"
    }
}

struct MissDistance: Decodable {
    let kilometers: String
    let miles: String
}

struct Kilometers: Decodable {
    let min: Double
    let max: Double
    
    enum CodingKeys: String, CodingKey {
        case min = "estimated_diameter_min"
        case max = "estimated_diameter_max"
    }
}

struct Meters: Decodable {
    let min: Double
    let max: Double
    
    enum CodingKeys: String, CodingKey {
        case min = "estimated_diameter_min"
        case max = "estimated_diameter_max"
    }
}

struct Miles: Decodable {
    let min: Double
    let max: Double
    
    enum CodingKeys: String, CodingKey {
        case min = "estimated_diameter_min"
        case max = "estimated_diameter_max"
    }
}

struct Feet: Decodable {
    let min: Double
    let max: Double
    
    enum CodingKeys: String, CodingKey {
        case min = "estimated_diameter_min"
        case max = "estimated_diameter_max"
    }
}

Answer 1

沒有看到 JSON，我只是猜測你希望你的NEObjects結構看起來像這樣：

struct NEObjects: Decodable {
    let objectsByDay : [String : NEObject]    
}

這將解碼 JSON，如下所示：

{
   "2021-02-16" : [
       { ... a bunch of your custom objects ... }
   ]
}

Answer 2

最終結果：我有一個不必要的額外層。 在執行約翰的建議后。

Model

import Foundation

struct NEOData: Decodable  {
    let elementCount: Int
    let neObjects: [String : [NEObject]]
    
    enum CodingKeys: String, CodingKey {
        case elementCount = "element_count"
        case neObjects = "near_earth_objects"
    }
}

struct NEObject: Decodable {
    let name: String
    let absoluteMagnitude: Double
    let diameter: Diameter
    let isHazardous: Bool
    let closeApproachData: [CloseApproachData]
    let isSentry: Bool
    
    enum CodingKeys: String, CodingKey {
        case name = "name"
        case absoluteMagnitude = "absolute_magnitude_h"
        case diameter = "estimated_diameter"
        case isHazardous = "is_potentially_hazardous_asteroid"
        case closeApproachData = "close_approach_data"
        case isSentry = "is_sentry_object"
    }
}

struct Diameter: Decodable {
    let kilometers: Kilometers
    let meters: Meters
    let miles: Miles
    let feet: Feet
}

struct CloseApproachData: Decodable {
    let velocity: Velocity
    let missDistance: MissDistance
    let date: String
    
    enum CodingKeys: String, CodingKey {
        case velocity = "relative_velocity"
        case missDistance = "miss_distance"
        case date = "close_approach_date"
    }
}

struct Velocity: Decodable {
    let mph: String
    let kph: String
    
    enum CodingKeys: String, CodingKey {
        case mph = "miles_per_hour"
        case kph = "kilometers_per_hour"
    }
}

struct MissDistance: Decodable {
    let kilometers: String
    let miles: String
}

struct Kilometers: Decodable {
    let min: Double
    let max: Double
    
    enum CodingKeys: String, CodingKey {
        case min = "estimated_diameter_min"
        case max = "estimated_diameter_max"
    }
}

struct Meters: Decodable {
    let min: Double
    let max: Double
    
    enum CodingKeys: String, CodingKey {
        case min = "estimated_diameter_min"
        case max = "estimated_diameter_max"
    }
}

struct Miles: Decodable {
    let min: Double
    let max: Double
    
    enum CodingKeys: String, CodingKey {
        case min = "estimated_diameter_min"
        case max = "estimated_diameter_max"
    }
}

struct Feet: Decodable {
    let min: Double
    let max: Double
    
    enum CodingKeys: String, CodingKey {
        case min = "estimated_diameter_min"
        case max = "estimated_diameter_max"
    }
}