CODEWITHSUNDEEP
iosjsonswiftparsing
George Heints
George Heints

Reputation: 1443

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

I am developing a project to learn how to parse JSON. I am trying to parse JSON to a struct. I am trying to do it using the code that comes next but I am getting the following error:

Err The data couldn’t be read because it isn’t in the correct format.

What am I doing wrong? Also I tried to use Alamofire but I didn't find way to parse it to struct.

func getData(){
    let gitUrl = URL(string: "http://95.46.99.250:9095/api/v1/institution-categories")
    URLSession.shared.dataTask(with: gitUrl!) { (data, response
        , error) in
        let data = data
        print(data)
        do {
            let decoder = JSONDecoder()
            let gitData = try decoder.decode([Root].self, from: data!)

        } catch let err {
            print("\nErr", err.localizedDescription)
        }
        }.resume()
}

Struct

struct Root: Codable {
    let  data: [InnerItem]
}
struct InnerItem:Codable {
    let  id: Int?
    let  image: String?
    let  name: String?

    private enum CodingKeys : String, CodingKey {
        case id = "id", image = "image", name = "name"
    }
}

JSON

{
"data": [
    {
        "id": 1,
        "name": "Пабы и бары",
        "image": "http://95.46.99.250:9095/storage/photos/[email protected]"
    },
    {
        "id": 2,
        "name": "Кафе",
        "image": "http://95.46.99.250:9095/storage/photos/[email protected]"
    },
    {
        "id": 3,
        "name": "Ночной клуб",
        "image": "http://95.46.99.250:9095/storage/photos/0201f7523bc2028f174710b51379e432.png"
    },
    {
        "id": 4,
        "name": "Ресторан",
        "image": "http://95.46.99.250:9095/storage/photos/[email protected]"
    },
    {
        "id": 5,
        "name": "Караоке-клуб",
        "image": "http://95.46.99.250:9095/storage/photos/microphone.png"
    },
    {
        "id": 6,
        "name": "Суши-бар",
        "image": "http://95.46.99.250:9095/storage/photos/sushi.png"
    },
    {
        "id": 7,
        "name": "Пиццерии",
        "image": "http://95.46.99.250:9095/storage/photos/pizza.png"
    },
    {
        "id": 8,
        "name": "Кальянная",
        "image": "http://95.46.99.250:9095/storage/photos/c111d1e5ad6b90b61ac36836d220ebba.png"
    },
    {
        "id": 9,
        "name": "Общая",
        "image": "http://95.46.99.250:9095/storage/photos/Group [email protected]"
    }
]
}

Upvotes: 50

Views: 80016

Answers (3)

Mojtaba Hosseini
Mojtaba Hosseini

Reputation: 119108

💡 Troubleshoot coding/decoding errors

When working with codables, instead of printing .localizedDescription, try to print out the error itself! so the compiler describes where the issue exactly is!

do {
    let decoder = JSONDecoder()
    let decoded = try decoder.decode([Root].self, from: data!)
} catch {
    // print(error.localizedDescription) // <- ⚠️ Don't use this!

    print(String(describing: error)) // <- ✅ Use this for debuging!
}

✅ In your case

it will point out that:

  • Decoder tried to decode the root object to an Array but found a Dictionary instead.

So you follow the issue and see that you should replace:

decoder.decode([Root].self, from: data!)

with:

decoder.decode(Root.self, from: data!)

Upvotes: 124

Dave Levy
Dave Levy

Reputation: 1172

For me, the issue with "The data couldn’t be read because it isn’t in the correct format." was something to do with the specific XLSX file I was trying to use. I created a new XLSX file in Excel, and added it to my project and that worked! Then I just pasted the data I needed from the file that was giving me the error into the newly created XLSX file and it parsed!

    static func load() {
    
    guard let filePath = Bundle.main.path(forResource: "test", ofType: "xlsx", inDirectory: nil) else {
        fatalError("XLSX file not exist")
    }
    
    let file = XLSXFile(filepath: filePath)
    
    do {
                   
        let parseBooks = try? file?.parseWorkbooks()
        
        for eachBook in parseBooks! {
            
            for (name, path) in try file!.parseWorksheetPathsAndNames(workbook: eachBook) {
    
                let worksheet = try file!.parseWorksheet(at: path)
                let sharedStrings = try file!.parseSharedStrings()
                print(sharedStrings)
    
            }
        }
    } catch {
        print("Error: \(error.localizedDescription)")
    }
  }

Upvotes: -3

Ratul Sharker
Ratul Sharker

Reputation: 8013

Try this

let gitData = try decoder.decode(Root.self, from: data!)

Traverse through your data

for singleData in gitData.data where (singleData.name ?? "") == "Cafe" {
    print(singleData.image)
}

Upvotes: 9

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