我从服务器返回了“几种”不同格式的 bool 值(对于相同的结构和字段)。我知道这很荒谬,但我需要找到一种方法来干净地处理它。
所以为了反序列化它,我做了类似的事情(示例程序):
import Foundation
struct Foo: Codable {
var isOpen: Bool?
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
isOpen = try container.decodeIfPresent(Bool.self, forKey: .isOpen)
}
enum CodingKeys: String, CodingKey {
case isOpen
}
}
//He sends any one of these..
let json1 = "{ \"isOpen\": \"true\" }"
let json2 = "{ \"isOpen\": \"false\" }"
let json3 = "{ \"isOpen\": true }"
let json4 = "{ \"isOpen\": false }"
let json5 = "{ \"isOpen\": null }"
let json6 = "{ \"isOpen\": \"null\" }"
let json7 = "{ \"isOpen\": \"<null>\" }"
//He doesn't send this one.. but I wouldn't be surprised if I got it so I added it for fun (serializing the below `json8` and `json9` is not required for an answer).. :)
let json8 = "{ \"isOpen\": 0 }"
let json9 = "{ \"isOpen\": 1 }"
let json = [json1, json2, json3, json4, json5, json6, json7, json8, json9]
for js in json {
if let rawData = js.data(using: .utf8) {
do {
let foo = try JSONDecoder().decode(Foo.self, from: rawData)
if let isOpen = foo.isOpen {
print("\(isOpen)\n\n")
} else {
print("State Unknown\n\n")
}
} catch {
print("\(error)\n\n")
}
}
}
现在,如果我使用 Swift Codable(我们所有的数据结构都已使用它),那么我们将得到类型不匹配并抛出错误/异常。我考虑过 try catch 每个案例并尝试使用不同类型的另一个解码但最终会像这样:
do {
isOpen = try container.decode(Bool.self, forKey: .isOpen)
}
catch {
do {
isOpen = try container.decode(Int.self, forKey: .isOpen) != 0
}
catch {
do {
isOpen = Bool(try container.decode(String.self, forKey: .isOpen))
}
catch {
do {
isOpen = try container.decodeIfPreset(Bool.self, forKey: .isOpen) ?? GiveUpAndAssignDefaultValueHere..
}
catch {
isOpen = nil //no idea..
}
}
}
}
然后这让我开始考虑先将它转换为字符串,然后尝试解析它,所以我最终得到了(至少比上面的更好):
do {
isOpen = try container.decode(Bool?.self, forKey: .isOpen)
}
catch {
do {
isOpen = Bool(try container.decode(String.self, forKey: .isOpen))
}
catch {
isOpen = try container.decode(Int.self, forKey: .isOpen) != 0
}
}
但肯定有更好的方法吗?有什么想法吗???
最佳答案
与其捕获
错误,不如有条件地绑定(bind)类型
struct Foo: Codable {
var isOpen: Bool?
init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
if let boolOpen = try? container.decode(Bool.self, forKey: .isOpen) {
isOpen = boolOpen
} else if let intOpen = try? container.decode(Int.self, forKey: .isOpen) {
isOpen = intOpen == 1
} else if let stringOpen = try? container.decode(String.self, forKey: .isOpen) {
switch stringOpen {
case "true", "1": isOpen = true
case "false", "0": isOpen = false
default : isOpen = nil
}
} else {
isOpen = nil
}
}
}
关于ios - Swift 解码具有多种不同格式的数据类型,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52489023/