While getting JSON data from my API, I can't get it to decode properly.
[
{
"success": "true",
"message": "testtt"
}
]
This is what my API output looks like.
As we can see, my PHP outputs the values as an top level array.
How can I read out this information in Swift 4?
let json = try JSONDecoder().decode([API].self, from: data)
returns:
success: "true", message: "testtt"
This is what the struct looks like:
struct API: Decodable{
let success: String
let message: String
init(jsont: [String: Any]){
success = jsont["success"] as? String ?? ""
message = jsont["message"] as? String ?? ""
}
}
But then I don't know how to read out this data further.
Any ideas?
There is no need to creat a custom initialiser. You just use the Array type [API].self when decoding your json:
struct API: Decodable{
let success: String
let message: String
}
let dataJSON = Data("""
[
{
"success": "true",
"message": "testtt"
}
]
""".utf8)
do {
if let result = try JSONDecoder().decode([API].self, from: dataJSON).first {
print(result.success)
print(result.message)
}
} catch {
print(error)
}
If you want to access make one more struct like
struct data: Decodable{
let API: [API]
}
Then in your program you must decode like below above
let json = try JSONDecoder().decode(data.self, from: data)
and access to them
data.API[i].success
data.API[i].message
Related
I'm receiving response data from an API, when I'm trying to decode it by using json decoder, the nested json data won't be decoded because it returns null.
json data as follow:
{
"token": "string",
"details": {
"ID": "string",
"Name": "string",
"Message": null
}
}
Decoding model is:
struct response: Codable {
let token: String?
let usrData: userData?
}
struct userData:Codable{
let ID,Name,Message: String?
}
URLSession.shared.dataTask(with: request) { (data, response, error) in
guard let data = data, error == nil else {
completion(.failure(.custom(errorMessage: "Please check internet connection")))
return
}
guard let loginResponse = try? JSONDecoder().decode(response.self, from:data) else
{
completion(.failure(.invalidCredentials))
return
}
print(loginResponse.userData?.userID as Any) //returns nil
print(loginResponse.token) //token printed
guard let token = loginResponse.token else {
completion(.failure(.invalidCredentials))
return
}
completion(.success(token))
}.resume()
The token from the response will be successfully decoded, but the userData returns null.
Your model's property name and decoded json property name must be equal if your are not mapping , so change your struct with :
struct response: Codable {
let token: String?
let details: userDto?
}
That certainly can not work, first, in your response struct you have a let variable that says usrData that can not be identified as details. Second you write usrData: userDto what is userDto you clearly did a mistake or forgot to mention it. However, do it like that for example:
struct Response: Codable {
let token: String?
let details: UserData?
}
struct UserData: Codable {
let ID,Name,Message: String?
}
let filePath = Bundle.main.path(forResource:"test", ofType: "json")
let data = try Data(contentsOf: URL(fileURLWithPath: filePath!))
if let loginResponse = try? JSONDecoder().decode(Response.self, from: data) {
loginResponse
}
The example is not completely correct, because fileURLWithPath is deprecated but you should get the idea from it.
I also recommend following some basic roles, like writing Structs with an uppercase letter.
I am trying to get the title from json data but I am getting an error. Here is my model object
struct SpaceNewsModel: Identifiable, Codable {
var id = UUID()
let title: String
let url: String
let source: String
}
And when I get to this point in my networking, I get an error.
let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in
if error != nil {
print(error!)
} else {
let decoder = JSONDecoder()
if let safeData = data {
do {
let astroNews = try decoder.decode([SpaceNewsModel].self, from: safeData)
print(astroNews[0].title)
} catch {
print("DEBUG: Error getting news articles \(error.localizedDescription)")
}
}
let httpResponse = response as? HTTPURLResponse
// print(httpResponse)
}
})
task.resume()
}
My main problem is with the line print(astroNews[0].title I am not formatting it right and I don't know how to access this data whether in an array or otherwise.
Here is the returned JSON data after making the request on the website postman.
[
{
"title": "Wales' new £2bn space strategy hopes",
"url": "https://www.bbc.co.uk/news/uk-wales-60433763",
"source": "bbc"
},
{
"title": "Could Port Talbot become a centre of space tech? Video, 00:02:02Could Port Talbot become a centre of space tech?",
"url": "https://www.bbc.co.uk/news/uk-wales-60471170",
"source": "bbc"
}
]
Normally there would be a title for each that I can access but here it is just the data. So to summarize, how would I get the first or second title in this JSON data? Because astroNews[0].title does not work.
EDIT: I want to clarify that if I were to decode an empty struct, I would not get any errors.
struct EMPTYSTRUCT: Codable {
}
But as soon as I add any variable like let title: String I get an error. I believe something is wrong in the formatting of the JSON because usually the JSON would look something this
{
"coord": {
"lon": -95.3633,
"lat": 29.7633
}
}
where I could name the struct "coord" however no such names exist in the returned JSON I'm working with. Only the variable names. The confusion is how would I construct my SpaceNewModel file to work with the returned JSON with no apparent object name.
With reference to this answer.
Just change your structure to
struct SpaceNewsModel: Identifiable, Codable {
let id = UUID()
let title: String
let url: String
let source: String
}
This is not the solution but a workaround; if you want to solve the issue, refer to this answer
I am attempting to parse JSON with codable in Swift. I have successfully done this before, but I have a more complicated JSON object with some arrays and I am having trouble.
Here is my JSON:
{
"data": [ {
"type":"player",
"id":"account.7e5b92e6612440349afcc06b7c390114",
"attributes": {
"createdAt":"2018-04-06T04:59:40Z",
"name":"bob",
"patchVersion":"",
"shardId":"pc-na",
"stats":null,
"titleId":"bluehole-pubg",
"updatedAt":"2018-04-06T04:59:40Z"
},
"relationships": {
"assets": {
"data":[]
},
"matches": {
"data": [
{"type":"match","id":"3e2a197a-1453-4569-b35b-99e337dfabc5"},
{"type":"match","id":"15f41d2f-9da2-4b95-95ca-b85e297e14b7"},
{"type":"match","id":"a42c496c-ad92-4d3e-af1f-8eaa2e200c2b"}
{"type":"match","id":"b6e33df5-4754-49da-9a0f-144842bfc306"},
{"type":"match","id":"5b357cd1-35fe-4859-a2d7-48f263120bbd"},
{"type":"match","id":"99fc5f81-c24c-4c82-ae03-cd21c94469c0"},
{"type":"match","id":"1851c88e-6fed-48e8-be84-769f20f5ee6f"},
{"type":"match","id":"e16db7ea-520f-4db0-b45d-649264ac019c"},
{"type":"match","id":"6e61a7e7-dcf5-4df5-aa88-89eca8d12507"},
{"type":"match","id":"dcbf8863-9f7c-4fc9-b87d-93fe86babbc6"},
{"type":"match","id":"0ba20fbb-1eaf-4186-bad5-5e8382558564"},
{"type":"match","id":"8b104f3b-66d5-4d0a-9992-fe053ab4a6ca"},
{"type":"match","id":"79822ea7-f204-47f8-ae6a-7efaac7e9c90"},
{"type":"match","id":"1389913c-a742-434a-80c5-1373e115e3b6"}
]
}
},
"links": {
"schema":"",
"self":"https://api.playbattlegrounds.com/shards/pc-na/players/account.7e5b92e6612440349afcc06b7c390114"
}
}],
"links": {
"self":"https://api.playbattlegrounds.com/shards/pc-na/players?filter[playerNames]=dchilds64"
},
"meta":{}
}
Here are the models I am using:
public struct PlayerResponse: Codable {
let data: [Player]
}
For Player:
public struct Player: Codable {
let type: String
let id: String
let attributes: Attributes
let relationships: Relationships
}
For Attributes:
public struct Attributes: Codable {
let name: String
let patchVersion: String
let shardId: String
let titleId: String
let updatedAt: String
}
For Relationships:
public struct Relationships: Codable {
let matches: Matches
}
For Matches:
public struct Matches: Codable {
let data: [Match]
}
For Match:
public struct Match: Codable {
let type: String
let id: String
}
Decoding as:
let players = try decoder.decode([Player].self, from: jsonData)
I have this function which runs my network request:
func getPlayerData(for name: String, completion: ((Result<[Player]>) -> Void)?) {
var urlComponents = URLComponents()
urlComponents.scheme = "https"
urlComponents.host = "api.playbattlegrounds.com"
urlComponents.path = "/shards/\(regionShard.rawValue)/players"
let playerNameItem = URLQueryItem(name: "filter[playerNames]", value: "\(name)")
urlComponents.queryItems = [playerNameItem]
guard let url = urlComponents.url else { fatalError("Could not create URL from components") }
print(url)
var request = URLRequest(url: url)
request.httpMethod = "GET"
request.setValue("bearer \(apiKey)", forHTTPHeaderField: "Authorization")
request.setValue("application/vnd.api+json", forHTTPHeaderField: "Accept")
let config = URLSessionConfiguration.default
let session = URLSession(configuration: config)
let task = session.dataTask(with: request) { (responseData, response, responseError) in
DispatchQueue.main.async {
if let error = responseError {
completion?(.failure(error))
} else if let jsonData = responseData {
let decoder = JSONDecoder()
do {
let players = try decoder.decode([Player].self, from: jsonData)
completion?(.success(players))
} catch {
completion?(.failure(error))
}
} else {
let error = NSError(domain: "", code: 0, userInfo: [NSLocalizedDescriptionKey : "Data was not retrieved from request"]) as Error
completion?(.failure(error))
}
}
}
task.resume()
}
The problem I am facing is that I get this error when I try to run the network request:
I think there is an issue with my codable structs, but I'm not sure. Could someone point me in the right direction to look for my error?
I suggest you build this up from the ground, since the errors of JSONDecoder (as with any compiler) get worse the more involved your structures are. Let's see how far we get:
Your Match struct is pretty sound:
public struct Match: Codable {
let type: String
let id: String
}
let decoder = JSONDecoder()
let mData = """
{"type":"match","id":"3e2a197a-1453-4569-b35b-99e337dfabc5"}
""".data(using:.utf8)!
let match = try! decoder.decode(Match.self, from:mData)
print(match)
No unexpected problems here. Shortening Matches a bit you already get your first error, rather an unexpected one
public struct Matches: Codable {
let data: [Match]
}
let mtchsData = """
{
"data": [
{"type":"match","id":"3e2a197a-1453-4569-b35b-99e337dfabc5"},
{"type":"match","id":"15f41d2f-9da2-4b95-95ca-b85e297e14b7"},
{"type":"match","id":"a42c496c-ad92-4d3e-af1f-8eaa2e200c2b"}
{"type":"match","id":"b6e33df5-4754-49da-9a0f-144842bfc306"},
{"type":"match","id":"5b357cd1-35fe-4859-a2d7-48f263120bbd"}
]
}
""".data(using:.utf8)!
do {
let mtches = try decoder.decode(Matches.self, from:mtchsData)
print(mtches)
} catch {
print(error)
}
will print the following error:
"dataCorrupted(Swift.DecodingError.Context(codingPath: [],
debugDescription: "The given data was not valid JSON.",
underlyingError: Optional(Error Domain=NSCocoaErrorDomain Code=3840
"Badly formed array around character 233."
UserInfo={NSDebugDescription=Badly
formed array around character 233.})))\n"
This is a trivial error, you are missing a comma on line 3 of the data Array. Adding that all will go well, but if it comes like this from your service you will have to fix it first.
I guess you get the idea and know your way about building up the structure successively. On the top level you will notice that your top level structure goes beyond an array of Player, it is actually a Dictionary with "data" as its sole key as you modelled correctly in PlayerResponse as #AnkitJayaswal pointed out already. That makes two errors already, those are the ones I managed to spot easily, but as I suggested before you should continue the build up of tests, that way you will know that the "lower" levels parse correctly and can concentrate on the problem at hand.
All of the above works easily in a Playground and there is no need to actually call the WebService in the process. Of course you will have to import Cocoa, but you already knew that. Anyway it always helps to reduce the level of complexity by splitting up your problem into smaller parts.
As I can see your whole player response is in key data. And your parsing player info with Player codable struct directly rather than data key which is used in PlayerResponse codable struct.
To resolve this update your code as:
let players = try decoder.decode(PlayerResponse.self, from: jsonData)
Hope this will solve your problem.
I receive from a post request, this JSON:
"clinic_info": {
"city": "Querétaro",
"state": "Querétaro",
"country": "México",
"phone": null,
"ext": null,
"coords": "20.6046089,-100.37826050000001",
"location": "Querétaro"
}
But when it is empty the JSON is:
"clinic_info": []
This produces an error: Expected to decode Dictionary but found an array instead.
This is happening because decoder want dictionary and your JSON is array
Need to check before decoding that JSON response is dictionary or Array and do decoding accordingly.
If you find Dictionary then do like this
let myData = try JSONDecoder().decode(YourModel.self, from: jsonData)
If you find Array then do like this
let myData = try JSONDecoder().decode([YourModel].self, from: jsonData)
You can do it using try, throw like that
import Foundation
struct ClinicData: Codable {
let clinicInfo: ClinicInfo?
enum CodingKeys: String, CodingKey {
case clinicInfo = "clinic_info"
}
}
struct ClinicInfo: Codable {
let city, state, country: String
let coords, location: String
}
// MARK: Convenience initializers
extension ClinicData {
init(data: Data) throws {
self = try JSONDecoder().decode(ClinicData.self, from: data)
}
init(_ json: String, using encoding: String.Encoding = .utf8) throws {
guard let data = json.data(using: encoding) else {
throw NSError(domain: "JSONDecoding", code: 0, userInfo: nil)
}
try self.init(data: data)
}
func jsonData() throws -> Data {
return try JSONEncoder().encode(self)
}
func jsonString(encoding: String.Encoding = .utf8) throws -> String? {
return String(data: try self.jsonData(), encoding: encoding)
}
}
**get clinicInfo**
if let clinicData = try? ClinicData.init(data: Data()), let clinicInfo =
clinicData.clinicInfo{
}
The service that provides those JSON responses replies with:
"clinic_info": { ... }
Where ... is a valid JSON object.
But when it is empty, you are saying it looks like this:
"clinic_info": []
Notice the [] that say this is an empty array of objects.
You might want to change the service response (if possible), since it looks inconsistent to me having it return an object when it has valid data, and an array when there is no valid data.
The error message you are getting is clear:
Expected to decode Dictionary but found an array instead.
It expected an object {}, but found an array [].
The Array class has a method for this.
Using typeof will always return "object".
The code below shows how to use the isArray() method in the Array class.
const obj = {
_array: [],
_object: {}
}
console.log(Array.isArray(obj._array)); // true
console.log(Array.isArray(obj._object)); // false
I got this JSON object which I sent from my server to my Swift application.
{
"625289": {
"id": 1,
"subject": "Hello World"
},
"625277": {
"id": 2,
"subject":"Bye World!"
}
}
So i tried to get the subject for each result ("625289" and "625277") by doing as below in my Swift class:
struct Resultat : Decodable {
let subject: String
}
var result = [Resultat]()
let urlll = URL(string:"http://localhost:8888/api/pouet.php")
URLSession.shared.dataTask(with: urlll!) { (data, response, error) in
do {
print("coucoulol")
//print(response)
self.result = try JSONDecoder().decode([Resultat].self, from: data!)
print(self.result)
for eachTicket in self.result {
print(eachTicket.subject)
}
} catch {
print("error"+error.localizedDescription)
}
}.resume()
However, when I tried to execute the code, it says "The data couldn’t be read because it isn’t in the correct format." From what I understand, the loop for in the code is suffice to get the values in the arrays or maybe I'm wrong. Any help is appreciated, thanks.
The root object is a dictionary. You can decode the object to [String:Resultat]. The dictionary contains also dictionaries. An array is not involved.
struct Resultat : Decodable {
let subject: String
let id : Int
}
...
let result = try JSONDecoder().decode([String:Resultat].self, from: data!)
for (key, value) in result {
print(key, value.subject)
}
You can try using SwiftyJSON below
$0.0 = Key
$0.1 = value
let data = JSON(result)
data.dictionaryValue.forEach({
print($0.1)
})