Converting Codable/Encodable to JSON object swift

Question

Recently i incorporated Codable in a project and to get a JSON object from a type conforming to Encodable i came up with this extension,

extension Encodable {

    /// Converting object to postable JSON
    func toJSON(_ encoder: JSONEncoder = JSONEncoder()) -> [String: Any] {
        guard let data = try? encoder.encode(self),
              let object = try? JSONSerialization.jsonObject(with: data, options: .allowFragments),
              let json = object as? [String: Any] else { return [:] }
        return json
    }
}

This works well but could there be any better way to achieve the same?

Answer 1

My suggestion is to name the function toDictionary and hand over possible errors to the caller. A conditional downcast failure (type mismatch) is thrown wrapped in an typeMismatch de coding error.

extension Encodable {

    /// Converting object to postable dictionary
    func toDictionary(_ encoder: JSONEncoder = JSONEncoder()) throws -> [String: Any] {
        let data = try encoder.encode(self)
        let object = try JSONSerialization.jsonObject(with: data)
        guard let json = object as? [String: Any] else {
            let context = DecodingError.Context(codingPath: [], debugDescription: "Deserialized object is not a dictionary")
            throw DecodingError.typeMismatch(type(of: object), context)
        }
        return json
    }
}

Answer 2

Convert encodable object to JSON string using this extension:

extension Encodable {
    /// Converting object to postable JSON
    func toJSON(_ encoder: JSONEncoder = JSONEncoder()) throws -> NSString {
        let data = try encoder.encode(self)
        let result = String(decoding: data, as: UTF8.self)
        return NSString(string: result)
    }
}