Firestore 自定义文档数据映射答案

【问题标题】：Firestore custom document data mappingFirestore 自定义文档数据映射
【发布时间】：2022-01-12 19:08:30
【问题描述】：

我在 Firestore 中有以下数据结构。我很难将它映射到我的 ios 应用程序。我正在使用斯威夫特。任何人都可以提供可编码的结构或其他东西吗？

struct CartModel: Codable {

    let cart: [CartItemModel]
   
    enum CodingKeys: String, CodingKey {
        case cart
    }    
}

extension CartModel{
    static var dummyCartData : CartModel {
        .init(cart: [CartItemModel.dummyCartData])
    }
}


struct CartItemModel: Codable {
    let brand: String
    let itemDescription: String
    let image: String
    let selection: [UserSelection]
    let title:String    
   
    enum CodingKeys: String, CodingKey {
        
        case brand
        case itemDescription = "description"
        case image
        case selection
        case title

    }
}


extension CartItemModel{
    static var dummyCartData : CartItemModel {

        .init(brand: "gucci",
              itemDescription: "adidas",
              image: "yeezy",
              selection: [UserSelection.dummyData],
              title: "123")
    }
}


struct UserSelection: Codable, Equatable{
    var size :String
    var count : Int

    enum CodingKeys: String, CodingKey {
        case size = "size"
        case count
    }

}

extension UserSelection{

    static var dummyData : UserSelection {

        .init(size: "XS11", count: 20)
    }
}


    docRef.getDocument { (snapshot, error) in
        if error != nil {
            return
        }

        if let snapshot = snapshot, snapshot.exists {
            print(snapshot.data())
        let products = try! snapshot.data(as: CartModel.self)
            print(products)
       
        }
    }

Firestore 返回

Optional(["cart": <__NSArrayM 0x600002979380>(
{
    brand = Nike;
    description = "Find the Jordan Point Lane at . ";
    image = "https://static.nike.com/a/images/t_default/f105dd55-53d0-4a50-b43a-55bd9231c658/jordan-point-lane-mens-shoes-PPMHdC.png";
    selection =     {
        count = 1;
        size = "";
    };
    title = "Jordan Point Lane Men's Shoes";
}
)
])

致命错误：“试试！”表达式意外引发错误：Swift.DecodingError.typeMismatch(Swift.Array, Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "cart", intValue: nil),

_FirestoreKey(stringValue: "Index 0", intValue: 0), CodingKeys(stringValue: "selection", intValue: nil)], debugDescription: "Not an array", underlyingError: nil))

致命错误：“试试！”表达式意外引发错误：Swift.DecodingError.typeMismatch(Swift.Array, Swift.DecodingError.Context(codingPath: [CodingKeys(stringValue: "cart", intValue: nil), _FirestoreKey(stringValue: "Index 0", intValue: 0 ), CodingKeys(stringValue: "selection", intValue: nil)], debugDescription: "Not an array", underlyingError: nil))

【问题讨论】：

标签： ios swift iphone google-cloud-firestore mapping

【解决方案1】：

正如错误所说，selection 不是 Firestore 文档中的数组，但您已将其定义为模型中的数组。

将let selection: [UserSelection] 更改为let selection: UserSelection

【讨论】：