Qfyilyi

I'm making a basic IOS app, based on the "App development with Swift" book from Apple. My app uses the Marvel API. I'm trying to reach the name and the description of the heroes.

The connection with the API works completely and has been tested multiple times. The problem hasn't anything do to with this.

My problem is the fact that the JSON result is 3 times nested, I have no idea how to reach this in Swift 4.

Here is an example of the JSON result of 1 hero. All Heroes can be found in the "result"

The JSON structure can be found here

My code has a fatal error:

Swift.DecodingError.keyNotFound(CodingKeys(stringValue: "results", intValue: nil)

let jsonDecoder = JSONDecoder()

    let task = URLSession.shared.dataTask(with: url) { (data,

        response, error) in

        try! jsonDecoder.decode(CharactersContainer.self, 

from: data!) //error here

        if let data = data,

            let char = try? jsonDecoder.decode(CharactersContainer.self, from: data) {

            print(char.characters)

            print("succes")



        } else {

            print("failed")

        }

    }

Now here are my models:

import Foundation



struct Character: Codable {

    var name: String

    var description: String

    //var url: Image





    enum CodingKeys: String, CodingKey {

        case name

        case description

        //case url = "thumbnail"



    }

    init(from decoder: Decoder) throws {

        let valueContainer = try decoder.container(keyedBy: CharactersContainer.CodingKeys.self).nestedContainer(keyedBy: Characters.CodingKeys.self, forKey: .characters).nestedContainer(keyedBy: Character.CodingKeys.self, forKey: .characters)

        if let name = try valueContainer.decodeIfPresent(String.self, forKey: CodingKeys.name) {

            self.name = name

        } else {

            self.name = ""

        }

        if let description = try valueContainer.decodeIfPresent(String.self, forKey: CodingKeys.description) {

            self.description = description

        } else {

            self.description = ""

        }



       // self.url = try valueContainer.decode(URL.self, forKey: CodingKeys.url)



    }

}







struct Characters : Decodable{

    var characters : [Character]

    enum CodingKeys: String, CodingKey {

        case characters = "data"

    }

}



struct CharactersContainer : Decodable {

    var characters : Characters

    //var total: Int

    enum CodingKeys: String, CodingKey {

        case characters = "results"

        //case total

    }

}

I have no idea what I did wrong, since I saw some examples who did the exact same thing.

Thanks for checking in!

In the JSON, data contains the results key. The way your keys are set up, it's expecting results to contain a data key.

CharactersContainer.CodingKeys.characters should probably be "data"

Characters.CodingKeys.characters should probably be "results"

Edit:

There's another issue in Character. It is trying to get a contain keyed by CharactersContainer.CodingKeys.self but it should probably be Character.CodingKeys.self