ios swift json data to dictionary - ios

Question

I have following format of data from a php script
{"Response":"OK","Data":{"ID":"1","data1":"sample1"}}
I need to extract data1 using http in swift, below is the code, but the code is not working as expected, that is if let data = dict?["Data"] as? [[String:Any]] { not giving any return.
fetchDataFromDB { (dict, error) in
if(dict?["Response"] as! String == "OK"){
var dd = dict?["Data"] as? [String:Any]
if let data = dict?["Data"] as? [[String:Any]] {
for d in data {
if let data1 = d["data1"] as? String {
self.data1 = data1
}
}
}
}
The function fetchDataFromDB
func fetchDataFromDB(completion: #escaping ([String:Any]?, Error?) -> Void) {
let url = URL(string: "http://test.com/get__details.php")!
let task = URLSession.shared.dataTask(with: url) { (data, response, error) in
guard let data = data else { return }
do {
if let array = try JSONSerialization.jsonObject(with: data, options: .allowFragments) as? [String:Any]{
completion(array, nil)
}
} catch {
print(error)
completion(nil, error)
}
}
task.resume()
}

Answer 1

The (unused) line above is correct, it's a dictionary. And handle the error
fetchDataFromDB { (dict, error) in
if let error = error { print(error); return }
if let dict?["Response"] as? String == "OK",
let data = dict?["Data"] as? [String:Any],
let data1 = data["data1"] as? String {
self.data1 = data1
}
}
And as the expected type of the root object is a dictionary name it accordingly
if let dictionary = try JSONSerialization...
Consider to use Codable to parse the JSON

Answer 2

Best practice is to use Codable considering the json example that you gave your class should look like:
import Foundation
// MARK: - ResponseDB
struct ResponseDB: Codable {
let response: String
let data: DataClass
enum CodingKeys: String, CodingKey {
case response = "Response"
case data = "Data"
}
}
// MARK: - DataClass
struct DataClass: Codable {
let id, data1: String
enum CodingKeys: String, CodingKey {
case id = "ID"
case data1
}
}
In order to decode the response to your class add this code to your class or a custom class:
// MARK: - Helper functions for creating encoders and decoders
func newJSONDecoder() -> JSONDecoder {
let decoder = JSONDecoder()
if #available(iOS 10.0, OSX 10.12, tvOS 10.0, watchOS 3.0, *) {
decoder.dateDecodingStrategy = .iso8601
}
return decoder
}
func newJSONEncoder() -> JSONEncoder {
let encoder = JSONEncoder()
if #available(iOS 10.0, OSX 10.12, tvOS 10.0, watchOS 3.0, *) {
encoder.dateEncodingStrategy = .iso8601
}
return encoder
}
// MARK: - URLSession response handlers
extension URLSession {
fileprivate func codableTask<T: Codable>(with url: URL, completionHandler: #escaping (T?, URLResponse?, Error?) -> Void) -> URLSessionDataTask {
return self.dataTask(with: url) { data, response, error in
guard let data = data, error == nil else {
completionHandler(nil, response, error)
return
}
completionHandler(try? newJSONDecoder().decode(T.self, from: data), response, nil)
}
}
func responseDBTask(with url: URL, completionHandler: #escaping (ResponseDB?, URLResponse?, Error?) -> Void) -> URLSessionDataTask {
return self.codableTask(with: url, completionHandler: completionHandler)
}
}
To read value from url:
let task = URLSession.shared.responseDBTask(with: YOUR_URL_HERE) { responseDB, response, error in
if let responseDB = responseDB {
if responseDB.response == "OK" {
self.data1 = responseDB.data.data1
}
}
}
task.resume()