Swift 5 中的 JSON 对象

Question

我正在尝试访问下面的 json api 中的数据

"Products": [
            {
                "ProductName": "GR",
                "ShortDescription": "General service epoxy mortar system that utilizes recycled glass and rapidly renewable soy based components.",
                "PDSOverride": [
                    {
                        "FileName": "EcoLab Netherlands",
                        "FileUrl": "http://test.stonhard.com/media/2264/eco-lab-netherlands-usa-version.pdf"
                    },
                    {
                        "FileName": "General Dynamics.pdf",
                        "FileUrl": "http://test.stonhard.com/media/2060/general-dynamics.pdf"
                    }
                ]
            }
        ]

我在下面这样的结构中对此进行建模

struct Solutions: Codable, Identifiable {
    let id = UUID()
    let SectionTitle: String
    let SectionImage: String
    let ProductLines: [ProductLine]
}

struct ProductLine: Codable {
    let System: String
    let Products: [Product]
}

struct Product: Codable {
    let ProductName: String
    let ShortDescription: String
    let PDSOverride: [PDSOverride]
}

struct PDSOverride: Codable {
    let FileName: String
    let FileUrl: String
}

struct SdsPdf: Codable {
    let FileName: String
    let FileUrl: String
}

struct GuideSpecPdf: Codable {
    let FileName: String
    let FileUrl: String
}   

当我尝试访问数据时，我收到一条错误消息，指出无法读取数据，因为它的格式不正确。我知道这是我的模型的问题，因为当我注释掉 PDSOverride、SdsPdf 和 GuideSpecPdf 时它可以工作，但显然我无权访问这些数据。如何对我的结构进行建模以便提取数据？

Answer 1

问题不在于您的模型，您的 JSON 格式错误，正如编译器所说，您的 JSON 需要如下所示：

[
    { 
        "Products": [
            {
                "ProductName": "GR",
                "ShortDescription": "General service epoxy mortar system that utilizes recycled glass and rapidly renewable soy based components.",
                "PDSOverride": [
                    {
                        "FileName": "EcoLab Netherlands",
                        "FileUrl": "http://test.stonhard.com/media/2264/eco-lab-netherlands-usa-version.pdf"
                    },
                    {
                        "FileName": "General Dynamics.pdf",
                        "FileUrl": "http://test.stonhard.com/media/2060/general-dynamics.pdf"
                    }
                ]
            }
        ]
    }
]

另外，模型也可以这样做，推荐你用Quicktype (https://app.quicktype.io) 在线版不错，有桌面版：

// MARK: - PurpleProduct
struct PurpleProduct: Codable {
    let products: [ProductProduct]

    enum CodingKeys: String, CodingKey {
        case products = "Products"
    }
}

// MARK: - ProductProduct
struct ProductProduct: Codable {
    let productName, shortDescription: String
    let pdsOverride: [PDSOverride]

    enum CodingKeys: String, CodingKey {
        case productName = "ProductName"
        case shortDescription = "ShortDescription"
        case pdsOverride = "PDSOverride"
    }
}

// MARK: - PDSOverride
struct PDSOverride: Codable {
    let fileName: String
    let fileURL: String

    enum CodingKeys: String, CodingKey {
        case fileName = "FileName"
        case fileURL = "FileUrl"
    }
}

typealias Products = [PurpleProduct]

要解码你可以使用 JSONDecoder，我也建议你在这个页面检查你的 json：https://jsonformatter.curiousconcept.com

Answer 2

假设您的 JSON 只缺少右大括号，您可以像这样解析它：

struct Entry: Codable {
    let products: [Product]

    enum CodingKeys: String, CodingKey {
        case products = "Products"
    }
}

struct Product: Codable {
    let productName, shortDescription: String
    let pdsOverride: [PDSOverride]

    enum CodingKeys: String, CodingKey {
        case productName = "ProductName"
        case shortDescription = "ShortDescription"
        case pdsOverride = "PDSOverride"
    }
}

struct PDSOverride: Codable {
    let fileName: String
    let fileURL: String

    enum CodingKeys: String, CodingKey {
        case fileName = "FileName"
        case fileURL = "FileUrl"
    }
}

do {
    let entries = try JSONDecoder().decode([Entry].self, from: data)
} catch {
    print(error)
}