How to get json fields? - json

Question

I follow a lesson from one course
And I need to get json, but i want get another json than in a lesson.
So this is my json:
https://api.scryfall.com/cards/search?q=half
And code:
struct Card {
var cardId: String
var name: String
var imageUrl: String
var text: String
init?(dict: [String: AnyObject]){
guard let name = dict["name"] as? String,
let cardId = dict["cardId"] as? String,
let imageUrl = dict["imageUrl"] as? String,
let text = dict["text"] as? String else { return nil }
self.cardId = cardId
self.name = name
self.imageUrl = imageUrl
self.text = text
}
}
class CardNetworkService{
private init() {}
static func getCards(url: String, completion: #escaping(GetCardResponse) -> ()) {
guard let url = URL(string: url) else { return }
NetworkService.shared.getData(url: url) { (json) in
do {
print ("ok1")
let response = try GetCardResponse(json: json)
print ("ok2")
completion(response)
} catch {
print(error)
}
}
}
}
class NetworkService {
private init() {}
static let shared = NetworkService()
func getData(url: URL, completion: #escaping (Any) -> ()) {
let session = URLSession.shared
session.dataTask(with: url) { (data, response, error) in
guard let data = data else { return }
do {
let json = try JSONSerialization.jsonObject(with: data, options: [])
DispatchQueue.main.async {
completion(json)
}
print(json)
} catch {
print(error)
}
}.resume()
}
}
struct GetCardResponse{
let cards: [Card]
init(json: Any) throws {
guard let array = json as? [[String: AnyObject]] else { throw NetworkError.failInternetError }
var cards = [Card]()
for dictionary in array {
guard let card = Card(dict: dictionary) else { continue }
cards.append(card)
}
self.cards = cards
}
}
Problem in struct GetCardResponse and [[String: AnyObject]] because I dont know how to parse this type of json. I tried to change them in the likeness of json. But I dont really understand how it works and in which part of code i need to put json["data"] or something like this... Help pls. I just want get json fields tcgplayer_id, name, art_crop

Answer 1

As of your code, you can parse the required details as:
struct Card {
var cardId: String = ""
var name: String = ""
var imageUrl: String = ""
var text: String = ""
init(dict: [String: Any]) {
if let obj = dict["name"] {
self.name = "\(obj)"
}
if let obj = dict["tcgplayer_id"] {
self.cardId = "\(obj)"
}
if let obj = dict["image_uris"] as? [String:Any], let url = obj["art_crop"] {
self.imageUrl = "\(url)"
}
if let obj = dict["oracle_text"] {
self.text = "\(obj)"
}
}
static func models(array: [[String:Any]]) -> [Card] {
return array.map { Card(dict: $0) }
}
}
class CardNetworkService{
private init() {}
static func getCards(url: String, completion: #escaping([Card]?) -> ()) {
guard let url = URL(string: url) else { return }
NetworkService.shared.getData(url: url) { (json) in
print ("ok1")
if let jData = json as? [String:Any], let data = jData["data"] as? [[String:Any]] {
let response = Card.models(array: data)
completion(response)
}
completion(nil)
}
}
}
class NetworkService {
private init() {}
static let shared = NetworkService()
func getData(url: URL, completion: #escaping (Any) -> ()) {
let session = URLSession.shared
session.dataTask(with: url) { (data, response, error) in
guard let data = data else { return }
do {
let json = try JSONSerialization.jsonObject(with: data, options: [])
DispatchQueue.main.async {
completion(json)
}
} catch {
print(error)
}
}.resume()
}
}
CardNetworkService.getCards(url: "https://api.scryfall.com/cards/search?q=half") { (res) in
print(res ?? [])
}
Just paste this code in playground and it'll work.
Happy Coding :)

Answer 2

You are wrong get entry of data field.
First you need get data field in json. And parse to deeper.
Try use the code.
struct GetCardResponse{
let cards: [Card]
init(json: Any) throws {
guard let jsonObject = json as? [String: Any], let data = jsonObject["data"] as? [[String:AnyObject]] else { throw NetworkError.failInternetError }
var cards = [Card]()
for dictionary in data {
guard let card = Card(dict: dictionary) else { continue }
cards.append(card)
}
self.cards = cards
}
}
UPDATE:
init function in Card has something wrong. In your json cardId is not found
Card class maybe like this because cardId, imageUrl, text maybe not found. It is optional
struct Card {
var cardId: String?
var name: String
var imageUrl: String?
var text: String?
init?(dict: [String: AnyObject]){
guard let name = dict["name"] as? String else { return nil }
self.cardId = dict["cardId"] as? String
self.name = name
self.imageUrl = dict["imageUrl"] as? String
self.text = dict["text"] as? String
}
}

Answer 3

Try using Codable to parse the JSON data like so,
Create the models like,
struct Root: Decodable {
let cards: [Card]
enum CodingKeys: String, CodingKey {
case cards = "data"
}
}
struct Card: Decodable {
let tcgplayerId: Int
let name: String
let artCrop: String
}
Now parse your JSON data using,
if let data = data {
do {
let decoder = JSONDecoder()
decoder.keyDecodingStrategy = .convertFromSnakeCase
let response = try JSONDecoder().decode(Root.self, from: data)
print(response)
} catch {
print(error)
}
}
You can access the properties in cards of response like so,
response.cards.first?.tcgplayerId