How to create a collection of objects from a JSON - ios

Question

I'm learning Swift and want to make an app that will show the GPS coordinates of buses on a map. The bus lat and lon come from a JSON (excerpt below):
{
"result":[
{
"Lat":52.276408,
"Lon":21.167618,
"Time":"2018-08-24 11:50:05",
"Lines":"225",
"Brigade":"4"
},
{
"Lat":52.222656,
"Lon":21.102633,
"Time":"2018-08-24 11:51:03",
"Lines":"225",
"Brigade":"2"
},
{
"Lat":52.2100185,
"Lon":21.2054211,
"Time":"2018-08-24 11:51:08",
"Lines":"119",
"Brigade":"2"
},
{
"Lat":52.1676735,
"Lon":21.2222606,
"Time":"2018-08-24 11:51:07",
"Lines":"213",
"Brigade":"3"
}
]
}
I was thinking of creating a Bus class
class Bus {
var latitude : Double = 1.11
var longitude : Double = 2.22
var lines : Int = 0
init (lat: Double, lon: Double, line: Int) {
latitude = lat
longitude = lon
lines = line
}
}
But I'm trying to figure out how to create a collection of these bus objects from the JSON, which (in full) contains around 1000 objects (amount varies throughout the day).
Could someone point me in the right direction? I don't need the fully-coded solution, just some pointers on how should I approach this.
I will most likely be using the SwiftyJSON CocoaPod for JSON parsing, together with Alamofire for getting it.
Thank you!

Answer 1

you can use Below Codable class as Larme said in the comments.
import Foundation
class MyModelClass: Codable {
let result: [Result]
init(result: [Result]) {
self.result = result
}
}
class Result: Codable {
let lat, lon: Double
let time, lines, brigade: String
enum CodingKeys: String, CodingKey {
case lat = "Lat"
case lon = "Lon"
case time = "Time"
case lines = "Lines"
case brigade = "Brigade"
}
init(lat: Double, lon: Double, time: String, lines: String, brigade: String) {
self.lat = lat
self.lon = lon
self.time = time
self.lines = lines
self.brigade = brigade
}
}
If you wanted to use ObjectMapper then you can use below class
import Foundation
import ObjectMapper
class MyModelClass: Mappable {
var result: [Result]?
required init?(map: Map){
}
func mapping(map: Map) {
result <- map["result"]
}
}
class Result: Mappable {
var lat: NSNumber?
var lon: NSNumber?
var time: String?
var lines: String?
var brigade: String?
required init?(map: Map){
}
func mapping(map: Map) {
lat <- map["Lat"]
lon <- map["Lon"]
time <- map["Time"]
lines <- map["Lines"]
brigade <- map["Brigade"]
}
}

Answer 2

write List model like this
class BusListModel {
var list = [Bus]()
var longitude : Double = 2.22
var lines : Int = 0
init (With dict:[String:Any]) {
if let result = dict["result"] as? [[String:Any]]{
for busDetail in result{
let model = Bus(lat: **valueHere**, lon: **valueHere**, line: **valueHere**)
list.append(model)
}
}
}
}

Answer 3

Thank you all for the answers, especially #dahiya_boy
I customised the code posted by #dahiya_boy and ended up with exactly what I need.
Below is the code. I created a jsonString for example purposes.
import Foundation
class MyModelClass: Codable {
let busArray: [Bus]
enum CodingKeys: String, CodingKey {
case busArray = "result"
}
init(busArray: [Bus]) {
self.busArray = busArray
}
}
class Bus: Codable {
let lat, lon: Double
let time, lines, brigade: String
enum CodingKeys: String, CodingKey {
case lat = "Lat"
case lon = "Lon"
case time = "Time"
case lines = "Lines"
case brigade = "Brigade"
}
init(lat: Double, lon: Double, time: String, lines: String, brigade: String) {
self.lat = lat
self.lon = lon
self.time = time
self.lines = lines
self.brigade = brigade
}
}
var jsonString = """
{
"result":[
{
"Lat":52.276408,
"Lon":21.167618,
"Time":"2018-08-24 11:50:05",
"Lines":"225",
"Brigade":"4"
},
{
"Lat":52.222656,
"Lon":21.102633,
"Time":"2018-08-24 11:51:03",
"Lines":"225",
"Brigade":"2"
},
{
"Lat":52.2100185,
"Lon":21.2054211,
"Time":"2018-08-24 11:51:08",
"Lines":"119",
"Brigade":"2"
},
{
"Lat":52.1676735,
"Lon":21.2222606,
"Time":"2018-08-24 11:51:07",
"Lines":"213",
"Brigade":"3"
}
]
}
"""
if let jsonData = jsonString.data(using: .utf8) {
let decodedJSON = try! JSONDecoder().decode(MyModelClass.self, from: jsonData)
print("Latitude: \(decodedJSON.busArray[0].lat), Longitude: \(decodedJSON.busArray[0].lon), Line: \(decodedJSON.busArray[0].lines)")
}
This prints the following console output:
Latitude: 52.276408, Longitude: 21.167618, Line: 225