如何为Imgur JSON创建模型对象| Swift

Question

Imgur图片搜索响应有如下结构(简化):

{ "data": [  {"title" : "Kittens",
"images" : [ { "title" : "",
"descripton" : "",
"nsfw" : "",
"link" : "https://i.imgur.com/L1olKr1.jpg"
}, { "title" : "",
"descripton" : "",
"nsfw" : "",
"link" : "https://i.imgur.com/L1olKr1.jpg" }]
},{"title" : "Kittens",
"images" : [ { "title" : "",
"descripton" : "",
"nsfw" : "",
"link" : "https://i.imgur.com/L1olKr1.jpg"
}, { "title" : "",
"descripton" : "",
"nsfw" : "",
"link" : "https://i.imgur.com/L1olKr1.jpg" }]
}]
}

目标是为它创建一个模型。我的尝试:

struct RawServerResponse: Decodable {

// MARK: - ImageCategoy
struct ImageCategory: Codable {
let title: String
let images: [Image]
}
// MARK: - Image
struct Image: Codable {
let title, descripton, nsfw: String
let link: String
}

let data: [ImageCategory]
}
// We need to be getting an array of [ImageModel] as a result of decoding.
// Flattens nested json model to get data that only we need:
struct ImageModel: Decodable {
let title: String
let description: String
let nsfw: String
let link: String

init(from decoder: Decoder) throws {
let rawResponse = try RawServerResponse(from: decoder)

title = rawResponse.data.first!.title
description = rawResponse.data.first!.images.first!.descripton
nsfw = rawResponse.data.first!.images.first!.nsfw
link = rawResponse.data.first!.images.first!.link

}

调用不起作用:

let decodedImageModel : ImageModel = try JSONDecoder().decode(ImageModel.self, from: data)

我需要得到一个数组[ImageModel]。请告诉我是否有更简单的方法从imgur响应中获取图像。

---

更新1:最终答案包含了@Gereon的回应。注意:json中的一些值最终是null而不是string。要处理这种情况，需要添加'init'方法，为不存在的值提供空字符串:

import Foundation
struct ImgurResponse: Codable {
let data: [ImageData]
}
struct ImageData: Codable {
let title: String
let images: [Image]
}
struct Image: Codable {
let title, description, nsfw: String
let link: String

enum CodingKeys: String, CodingKey {
case title
case description
case nsfw
case link
}

init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
title = try container.decodeIfPresent(String.self, forKey: .title) ?? ""
description = try container.decodeIfPresent(String.self, forKey: .description) ?? ""
nsfw = try container.decodeIfPresent(String.self, forKey: .nsfw) ?? ""
link = try container.decodeIfPresent(String.self, forKey: .link) ?? ""
}
}

---

更新2:

或者，正如@Gereon所建议的，你可以将相应的属性标记为Optional，例如let link: String?这允许您摆脱手动CodingKeys和init实现。

Answer 1

不需要创建一个重复的ImageModel结构体，您可以直接从API响应中提取所需的信息:

struct ImgurResponse: Codable {
let data: [ImageData]
}
struct ImageData: Codable {
let title: String
let images: [Image]
}
struct Image: Codable {
let title, descripton, nsfw: String
let link: String
}
let response = try JSONDecoder().decode(ImgurResponse.self, from: data)
let images = response.data.flatMap { $0.images.compactMap { $0 }} // [Image]

Answer 2

Model

struct RawServerResponse: Decodable {

// MARK: - ImageCategoy
struct ImageCategory: Codable {
let title: String
let images: [Image]
}

// MARK: - Image
struct Image: Codable {
let title, descripton, nsfw: String
let link: String
}

let data: [ImageCategory]
}

// We need to be getting an array of [ImageModel] as a result of decoding.

// Flattens nested json model to get data that only we need:
struct ImageModel: Decodable {
let title: String
let description: String
let nsfw: String
let link: String


init(title: String, desc: String, nsfw: String, link: String) {
self.title = title
self.description = desc
self.nsfw = nsfw
self.link = link
}
}

struct ImageModels: Decodable {
let arrObj:[ImageModel]

init(from decoder: Decoder) throws {
let rawResponse = try RawServerResponse(from: decoder)
arrObj  = rawResponse.data.compactMap{ ImageModel(title: $0.title, desc: $0.images.first!.descripton, nsfw: $0.images.first!.nsfw, link: $0.images.first!.link)}
/*var arr: [ImageModel] = []
for imagecat in rawResponse.data{
let model = ImageModel(title: imagecat.title, desc: imagecat.images.first!.descripton, nsfw: imagecat.images.first!.nsfw, link: imagecat.images.first!.link)
arr.append(model)
}

arrObj = arr*/
}
}

解析

do{
let serverData = try Data(contentsOf: data)
let decodedImageModel : ImageModels = try JSONDecoder().decode(ImageModels.self, from: serverData)
print("Response Success: (decodedImageModel)")
}catch{
print("Error Data: (error.localizedDescription)")
}