Swift : The data couldn’t be read because it isn’t in the correct format

Question

I try to call the POST Api with Alamofire but it's showing me an error of incorrect format.

This is my JSON response:

[
  {
    "_source": {
      "nome": "LOTERIAS BELEM",
      "endereco": "R DO COMERCIO, 279",
      "uf": "AL",
      "cidade": "BELEM",
      "bairro": "CENTRO"
    },
    "_id": "010177175"
  },
  {
    "_source": {
      "nome": "Bel Loterias"
    },
    "_id": "80224903"
  },
  {
    "_source": {
      "nome": "BELLEZA LOTERIAS",
      "endereco": "R RIVADAVIA CORREA, 498",
      "uf": "RS",
      "cidade": "SANTANA DO LIVRAMENTO",
      "bairro": "CENTRO"
    },
    "_id": "180124986"
  }
]

---

class Album: Codable {
    var _source :  [_source]

}

class _source: Codable {
    var nome :  String
    var endereco : String
    var uf : String
    var cidade : String
    var bairro : String
}

var arrList = [Album]()

And this is how i try to Decoding with Alamofire.

func request() {

        let urlString = URL(string: "My Url")
      //  Alamofire.request(url!).responseJSON {(response) in

        Alamofire.request(urlString!, method: .post, parameters: ["name": "belem"],encoding: JSONEncoding.default, headers: nil).responseJSON {
            (response) in

            switch (response.result) {
            case .success:
                if let data = response.data {
                    do {
                        let response = try JSONDecoder().decode([Album].self, from: data)
                        DispatchQueue.main.async {
                             self.arrList = response
                        }
                    }
                    catch {
                        print(error.localizedDescription)
                    }
                }
            case .failure( let error):
                print(error)
            }
       }
 }

Solution 1

Just your Album model is incorrect.

struct Album: Codable {
    var source : Source
    var id     : String

    enum CodingKeys: String, CodingKey {
        case source = "_source"
        case id = "_id"
    }
}

struct Source: Codable {
    var nome     : String
    var endereco : String?
    var uf       : String?
    var cidade   : String?
    var bairro   : String?
}

If you don't want _id altogether then simply remove the related parts.
As for your Alamofire related code, that part is good.

---

Notable improvements:

• Have avoided underscored variable name in model by customizing CodingKeys for key mapping purpose
• Typenames should always start with a Capital letter (so _source is Source)
  • Similarly, variable names should always start with a lowercase letter
• Made some variables optional (based on your updated response)
  • Keeping a variable non-optional means it must be present in the response for the model to be created
  • Making a variable optional means that key may or may not be present in the response and it not being there won't prevent the model from being created

Solution 2

I would like to recommend you to use json4swift.com. You just have to copy your json and paste there. It will automatically create modal struct or class from your json.

Coming back to your question, Your class Album doesn't have array of [_source]. That's the reason you are getting following error "The data couldn’t be read because it isn’t in the correct format".

Try below given format of album class,

class Album: Codable
{ 
  var source: Source?
  var id: String?
}

Please try to avoid using underscore in Swift.

Comments

[vadian]

Never ever print error.localizedDescription when decoding JSON. Print error, it tells you exactly what's wrong. And stop using those ugly objective-c-ish underscore characters. Structs in Swift start with an uppercase letter!

[Krunal Nagvadia]

Ok i try this but keyNotFound(CodingKeys(stringValue: "_source", intValue: nil), Swift.DecodingError.Context(codingPath: [], debugDescription: "No value associated with key CodingKeys(stringValue: \"_source\", intValue: nil) (\"_source\").", underlyingError: nil)) Error is Showing

[staticVoidMan]

@KrunalNagvadia Share your json response. Seems "_source" is missing for some object. Anyways, share what logs with print(try? JSONSerialization.jsonObject(with: data, options: [])) in your alamofire request function

[Krunal Nagvadia]

[drive.google.com/file/d/1V25FAlCQRYNKVAp695SFOzQlLFO8AsIA/…

[staticVoidMan]

@KrunalNagvadia Hm... 7th object has only "nome" key and none of the rest. We'll have to make the rest optional in Source optional.

[staticVoidMan]

@KrunalNagvadia Check updated answer. Will add explanation in a short while.

[Krunal Nagvadia]

what change you make please explain

[staticVoidMan]

@KrunalNagvadia Check answer. The Source model has String? for all except nome. Meaning nome key will always be present in the response.

[Krunal Nagvadia]

Let us continue this discussion in chat.

[staticVoidMan]

@KrunalNagvadia I hope this answer has solved your problem. Kindly upvote/mark as accepted.

[Pedro Trujillo]

Thanks! you make me realize that all this time the problem was my model. :)