json - 使用 Codable 解析嵌套的 JSON

Question

所以我正在尝试使用 Swift 中的 Codable 解析看起来像这样的 JSON。

{
"abilities": [
    {
        "ability": {
            "name": "chlorophyll",
            "url": "https://pokeapi.co/api/v2/ability/34/"
        },
        "is_hidden": true,
        "slot": 3
    },
    {
        "ability": {
            "name": "overgrow",
            "url": "https://pokeapi.co/api/v2/ability/65/"
        },
        "is_hidden": false,
        "slot": 1
    }
],
"name": "SomeRandomName"
}

现在，当您尝试获取嵌套数据时，它会变得困惑。现在我正在尝试获取名称，这很容易。我也在尝试获取能力名称，这对我来说很复杂。经过一些研究，这就是我想出的。

class Pokemon: Codable {

struct Ability: Codable {
    var isHidden: Bool

    struct AbilityObject: Codable {
        var name: String
        var url: String
    }

    var ability: AbilityObject

    private enum CodingKeys: String, CodingKey {
        case isHidden = "is_hidden"
        case ability
    }
}

var name: String
var abilities: [Ability]
}

现在有没有更好的方法来做到这一点，或者我是否坚持这样做。

Answer 1

获取您的 JSON 响应并将其转储到 this site 中.

它会在没有 Codable 的情况下生成这些结构。添加 Codable 使它们看起来像这样:

struct Pokemon: Codable {
    let abilities: [AbilityElement]
    let name: String

    struct AbilityElement: Codable {
        let ability: Ability
        let isHidden: Bool
        let slot: Int

        struct Ability: Codable {
            let name: String
            let url: String
        }
    }
}

对于带有 snake_case 的键，您只需声明一个 JSONDecoder 并将 keyDecodingStrategy 指定为 .convertFromSnakeCase。如果您只是从 snake case 转换而来，则无需使用编码键。只有在重命名 key 时才需要它们。

如果您在其他情况下需要为响应创建自定义编码键或更改键名，this page应该会有所帮助。

你可以把它扔到 Playground 上玩:

let jsonResponse = """
{
    "abilities": [
    {
        "ability": {
        "name": "chlorophyll",
        "url": "https://pokeapi.co/api/v2/ability/34/"
    },
    "is_hidden": true,
    "slot": 3
    },
    {
    "ability": {
        "name": "overgrow",
        "url": "https://pokeapi.co/api/v2/ability/65/"
    },
    "is_hidden": false,
    "slot": 1
    }
    ],
    "name": "SomeRandomName"
}
"""

struct Pokemon: Codable {
    let abilities: [AbilityElement]
    let name: String

    struct AbilityElement: Codable {
        let ability: Ability
        let isHidden: Bool
        let slot: Int

        struct Ability: Codable {
            let name: String
            let url: String
        }
    }
}

var pokemon: Pokemon?

do {
    let jsonDecoder = JSONDecoder()
    jsonDecoder.keyDecodingStrategy = .convertFromSnakeCase
    if let data = jsonResponse.data(using: .utf8) {
        pokemon = try jsonDecoder.decode(Pokemon.self, from: data)
    }
} catch {
    print("Something went horribly wrong:", error.localizedDescription)
}

print(pokemon)