How to convert dinamically Swift classes to JSON and vice-versa? - json

Question

In my new project that act like a RPC, in some moment i receive a JSON with function name and a list of parameters. Example:
{
"f": "sample.login",
"p": [
{"n": "param1", "v": "value1"},
{"n": "param2", "v": true},
{"n": "param3", "v": {"id": 1, "title": "title xyz"}}
[...] any amount of params [...]
]
}
In other moments, i need create the same structure and encode as JSON. Example:
public class Param: Codable {
public var n: String
public var v: Any?
init(n: String, v: Any?) {
self.n = n
self.v = v
}
}
struct Todo: Codable {
var id: Int64
var title: String
var data: [String: String]
var done: Bool
}
public class JsonSerializer: Serializer {
private var decoder = JSONDecoder()
private var encoder = JSONEncoder()
public func encodeRequest(functionName: String, params: [Param]) -> String {
do {
let request = JsonRequestData(f: functionName, p: params)
let data = try encoder.encode(request)
if let result = String(data: data, encoding: .utf8) {
return result
} else {
print("[JsonSerializer : encodeRequest] Error when try to encode data")
}
} catch let e {
print("[JsonSerializer : encodeRequest] Error when try to encode data: \(e.localizedDescription)")
}
return ""
}
struct JsonRequestData: Codable {
let f: String
var p: [Param]
init(f: String, p: [Param]) {
self.f = f
self.p = p
}
}
}
let todo = Todo(id: 1, title: "Title 1", data: [:], done: true)
let name = "sample.todo.single"
var params: [Param] = []
params.append(Param(n: "suffix", v: "%"))
params.append(Param(n: "p2", v: todo))
let s = JsonSerializer()
let json = s.encodeRequest(functionName: name, params: params)
print(json)
I made it work in C++ (nlohmann json) and Kotlin (with gson). Only left make it work in Swift.
I know of course Swift doesn't support encoding ANY type. And I'm aware of some limitations on this in Swift.
But I would like to find a plausible solution to my problem.
Even if the user has to implement a protocol on his side for his types, or enter his type in a list of known types or something.
The project is at this URL, if you want to see the codes in more depth:
https://github.com/xplpc/xplpc
Removing this lock, the code is practically ready.
I tried on Apple forums, search on Google and on iOS group inside Slack.

Answer 1

Thanks for answers.
But after try a lot, i decide to use AnyCodable project (https://github.com/Flight-School/AnyCodable) with my modifications (https://github.com/xplpc/xplpc/tree/main/swift/lib/Sources).
AnyCodable let me use all swift types and if i use these types on my class/struct it works without problems.
To use any custom type, only need add more lines on AnyEncodable and AnyDecodable class.
Thanks.