Cannot cast/decode data from server into Swift data model? - ios

Question

I need to cast the below response from my server as [UserResult] but I cannot get it to work??
What am I doing wrong?
func userSearch(keyword: String, completion: #escaping (Result<[UserResult], ResponseError>) -> Void ) {
socket.emit("userSearch", keyword)
socket.on("userFound") { ( data, ack) in
print(data) // prints below NSArray
if !data.isEmpty {
if let response = data as? [UserResult] {
print("USERS \(response)") // WILL NOT WORK?
completion(.success(response))
}
} else {
completion(.failure(.badRequest("No users found")))
}
}
}
Data from server
[<__NSArrayM 0x60000040e5b0>(
{
profileUrl = "www.address1.com";
username = chrissmith;
},
{
profileUrl = "www.address2.com";
username = johnsmith;
},
{
profileUrl = "www.address3.com";
username = alicesmith;
}
)
]
UserResult Model
struct UserResult: Decodable {
let username: String
let profileUrl: String
}

Answer 1

Well you are using Socket.IO library and specifically method
socket.on(clientEvent: .connect) {data, ack in
...
}
defined as
#discardableResult
open func on(clientEvent event: SocketClientEvent, callback: #escaping NormalCallback) -> UUID
using typealias:
public typealias NormalCallback = ([Any], SocketAckEmitter) -> ()
So basically at the and you are being returned data of type [Any] according to documentation.
Since you do not know what is inside your data it is better for you to unwrap objects in your array one by one (instead casting it directly to [UserResult]) and try to find out what Type there are by comparing to some set of known types as some of answers from this question suggest.
I would start with verifying the data structure with example code below , and only move on with casting to various type afterwards:
Lets assume example data1 is your data:
let dict1 = ["profileUrl":"www.address1.com","username":"chrissmith"]
let data1: NSArray = [dict1]
//printed data1:
// (
// {
// profileUrl = "www.address1.com";
// username = chrissmith;
// }
// )
if data1[0] as? [String:String] != nil {
print("We found out that first object is dictionary of [String:String]!")
}
else if data1[0] as? Dictionary<NSObject, AnyObject> != nil {
print("We found out that first object is dictionary of mixed values!")
} else {
print("We found out that first object has different data structure")
}
Hopefully this answer was at least a little bit helpfull, even though not providing direct easy solution for your problem.