ScopedJsonDecoder

Based on https://github.com/aunnnn/NestedDecodable, this package allows you to select specific keys to decode from json, regardless of the nesting.

Installation SPM: https://github.com/Nevwild/ScopedJsonDecoder

Usage: For the following JSON:

let testJSON = """
{
"HappyPath":
{
    "firstKey": "a",
    "secondKey": "b",
    "thirdKey": "c"
},
"SnakeCamelMix":
{
    "camelKey": "e",
    "snake_key": "f",
    "double_snake_key": "g"
},
"outerContainer":
{
    "nestedContainer":
    {
        "firstKey": "nested a",
        "secondKey": "nested b",
        "thirdKey": "nested c",
        "innerNestedContainer":
        {
            "camelKey": "inner e",
            "snake_key": "inner f",
            "double_snake_key": "inner g"
        }
    }
}
}
"""
  .data(using: .utf16)!

You can decode to the HappyPath struct

struct HappyPath: Codable {
    let firstKey: String
    let secondKey: String
    let thirdKey: String
}

Using the following method on JSONDecoder():

JSONDecoder().decode(HappyPath.self, scopedToKey: "HappyPath", from: testJson)

The same decode() method is available direcly on Data types, so you could achieve the same result with:

testJson.decode(HappyPath.self, scopedToKey: "HappyPath")

If you wanted to decode structs from snake case (or even mixed with camel case):

struct SnakeCamelMix: Codable {
    let camelKey: String
    let snakeKey: String
    let doubleSnakeKey: String
}

Add a .convertFromSnakeCase after your scoped key:

try testJson.decode(SnakeCamelMix.self, scopedToKey: "SnakeCamelMix", .convertFromSnakeCase)

And if you wanted to get the innerNested SnakeCamelMix in the json, seperate the keys using periods, and put the resulting string into the scopedToKey parameter:

try testJson.decode(SnakeCamelMix.self, scopedToKey: "outerContainer.nestedContainer.innerNestedContainer", .convertFromSnakeCase)