Swift Codable: encode structure with dynamic keys

Question

I want to have the following JSON structure (fake example):

{
    "Admin" : 
    {
        "name" : "John",
        "age" : "42"
    },
    "Sales" : 
    {
        "name" : "John",
        "age" : "42"
    },
    "CEO" : 
    {
        "name" : "Peter",
        "age" : "52",
        "salary" : "100000"
    },
    "Janitor" : 
    {
        "name" : "Matthew",
        "age" : "22"
    }
}

As you can see, the structure if determined, but the name of the structure is dynamic.

How can I convert this to a Swift Codable struct? Current try:

struct Positions: Codable
{
    var posDicts: [String: Position] = [:]
}

struct Position: Codable
{
    let name: String
    let age: Int
    let salary: Int?
}

However, this would give the following:

"posDicts" : {
    "Admin" : 
    {
        "name" : "John",
        "age" : "42"
    },
    "Sales" : 
    {
        "name" : "John",
        "age" : "42"
    },
    "CEO" : 
    {
        "name" : "Peter",
        "age" : "52",
        "salary" : "100000"
    },
    "Janitor" : 
    {
        "name" : "Matthew",
        "age" : "22"
    }
}

I don't want the "posDicts" in the JSON. What would be the best/simplest solution?

P.S.: related question regarding decodable Swift Codable with dynamic keys

This might help: https://stackoverflow.com/questions/50713638/swift-codable-with-dynamic-keys — emrepun, Dec 11 '18 at 17:40
@emrepun as you might have noticed, that is the exact same link I provide in my question. (iow: need more than that) — Freek Sanders, Dec 11 '18 at 17:54

vadian · Answer 1 · 2018-12-11T18:59:28.083

2

Rather than decoding

let result = try JSONDecoder().decode(Positions.self, from: data)

delete the Positions struct and decode

let result = try JSONDecoder().decode([String:Position].self, from: data)

To encode the dictionary accordingly declare it as

 var positions = [String:Position]()

edited Dec 11 '18 at 18:59

answered Dec 11 '18 at 17:59

vadian

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score 0 · Answer 2 · answered Dec 11 '18 at 18:13

The answer by Vadian is a good push in the right direction. The solution was to encode the dictionary instead of a struct containing a dictionary.

As the original question is about encoding, the following is a complete solution:

var positions: [String: Position] = [:]
let json = try? encoder.encode(positions)

score 0 · Answer 3 · answered Sep 24 '21 at 01:54

0

Encoding with dynamic keys seems like it's not supported at the moment.

I have used dictionary instead of encodable model that requires dynamic keys.

let dict = [dynamicKey: dynamicValue]
class MyModel: Encodable {
      someModelKey: dict
}

answered Sep 24 '21 at 01:54

Ali

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Swift Codable: encode structure with dynamic keys

3 Answers3

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