Swift 4 JSON Decodable with multidimensional and multitype array

Question

{
"values":[
[1,1,7,"Azuan Child","Anak Azuan","12345","ACTIVE","Morning",7,12,"2017-11-09 19:45:00"],
[28,1,0,"Azuan Child2","Amran","123456","ACTIVE","Evening",1,29,"2017-11-09 19:45:00"]
]
}

Ok, this is my json format that i received from the server

Right now i want to decode it into my struct but still have no luck on it.

struct ChildrenTable: Decodable {
    var values: [[String]]?
}

And my caller method on URLSession look like this

URLSession.shared.dataTask(with: request) { (data, response, err) in
        guard let data = data else { return }

        let dataAsString = String(data: data, encoding: .utf8)
        print(dataAsString)

        do {
            let children  = try
                JSONDecoder().decode(ChildrenTable.self, from: data)
                print (children)
        } catch let jsonErr {
            print ("Error serializing json: ", jsonErr)
        }
    }.resume()

And the error that i got are

Error serializing json:  
typeMismatch(Swift.String, Swift.DecodingError.Context(codingPath: [Vito_Parent.ChildrenTable.(CodingKeys in _1B826CD7D9609504747BED0EC0B7D3B5).values, Foundation.(_JSONKey in _12768CA107A31EF2DCE034FD75B541C9)(stringValue: "Index 0", intValue: Optional(0)), 
Foundation.(_JSONKey in _12768CA107A31EF2DCE034FD75B541C9)(stringValue: "Index 0", intValue: Optional(0))], 
debugDescription: "Expected to decode String but found a number instead.", underlyingError: nil))

I know there's an int in the array and i only cast String for the values var values: [[String]]? ( the reason why this error popup), but i simply cannot use any multidimensional array or tuples in my structs since it follow the protocol of Decodable.

I also cannot convert the data into dictionary since it will throw error "Expected to decode Dictionary but found array instead"

Any ideas on solving this problem? i tried casting string type on data but still no luck...

p/s: if all the json format are in string type, there would be no problem, but i dont have the permission on changing that since i call it from API.

Answer 1

As you said, your json array is multi-type but you are trying to decode all into String. Default conformance of String to Decodable does not allow that. The only solution comes into my mind is to introduce new type.

struct IntegerOrString: Decodable {
    var value: Any

    init(from decoder: Decoder) throws {
        if let int = try? Int(from: decoder) {
            value = int
            return
        }

        value = try String(from: decoder)
    }
}

struct ChildrenTable: Decodable {
    var values: [[IntegerOrString]]?
}

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