How to read local JSON file and output JSON in swift? - json

Question

import Foundation
class ReadLocalJSON {
static func readJSONFromFile(fileName: String) -> JSON
{
var json: JSON
if let path = Bundle.main.path(forResource: fileName, ofType: "json") {
do {
let fileUrl = URL(fileURLWithPath: path)
let data = try Data(contentsOf: fileUrl, options: .mappedIfSafe)
json = try? JSONSerialization.jsonObject(with: data)
} catch {
print("Something goes wrong when reading local json file.")
}
}
return json
}
}
I try to read the local json file and output json. But the line json = try? JSONSerialization.jsonObject(with: data) gives an error saying Cannot assign value of type 'Any?' to type 'JSON'.
My json data looks like
{
"leagues":
[
{ "name": "Hockey",
"image": "hockey",
"games":
[
{
"game_state": "Final",
"game_time": 1456662600,
"home_team_city": "Alberta",
"home_team_name": "Pigs",
"home_team_score": 1,
"home_team_logo": "pig",
"visit_team_city": "Montreal",
"visit_team_name": "Fishes",
"visit_team_score": 4,
"visit_team_logo": "fish"
}
]
}
]
}
When I change the output type to be Any? I print the output and it seems missing some elements.
{
leagues = (
{
games = (
{
"game_state" = Final;
"game_time" = 1456662600;
...
How can I fix it?

Answer 1

Check the solution below, I used Codable for the JSON decoding.
import Foundation
struct Sports: Codable {
let leagues: [League]
}
struct League: Codable {
let name, image: String
let games: [Game]
}
struct Game: Codable {
let gameState: String
let gameTime: Int
let homeTeamCity, homeTeamName: String
let homeTeamScore: Int
let homeTeamLogo, visitTeamCity, visitTeamName: String
let visitTeamScore: Int
let visitTeamLogo: String
enum CodingKeys: String, CodingKey {
case gameState = "game_state"
case gameTime = "game_time"
case homeTeamCity = "home_team_city"
case homeTeamName = "home_team_name"
case homeTeamScore = "home_team_score"
case homeTeamLogo = "home_team_logo"
case visitTeamCity = "visit_team_city"
case visitTeamName = "visit_team_name"
case visitTeamScore = "visit_team_score"
case visitTeamLogo = "visit_team_logo"
}
}
class ReadLocalJSON {
static func readJSONFromFile(fileName: String) -> Sports?
{
let path = Bundle.main.path(forResource: fileName, ofType: "json")
let url = URL(fileURLWithPath: path!)
let sportsData = try? Data(contentsOf: url)
guard
let data = sportsData
else { return nil }
do {
let result = try JSONDecoder().decode(Sports.self, from: data)
print(result)
return result
} catch let error {
print("Failed to Decode Object", error)
return nil
}
}
}
ReadLocalJSON.readJSONFromFile(fileName: "test")

Answer 2

Step 1:- first make a modal class in your project
struct Welcome: Codable {
let leagues: [League]?
}
// MARK: - League
struct League: Codable {
let name, image: String?
let games: [Game]?
}
// MARK: - Game
struct Game: Codable {
let gameState: String?
let gameTime: Int?
let homeTeamCity, homeTeamName: String?
let homeTeamScore: Int?
let homeTeamLogo, visitTeamCity, visitTeamName: String?
let visitTeamScore: Int?
let visitTeamLogo: String?
enum CodingKeys: String, CodingKey {
case gameState = "game_state"
case gameTime = "game_time"
case homeTeamCity = "home_team_city"
case homeTeamName = "home_team_name"
case homeTeamScore = "home_team_score"
case homeTeamLogo = "home_team_logo"
case visitTeamCity = "visit_team_city"
case visitTeamName = "visit_team_name"
case visitTeamScore = "visit_team_score"
case visitTeamLogo = "visit_team_logo"
}
}
Step 2 : - After getting response write this line,
let decoder = JSONDecoder()
let obj = try! decoder.decode(Welcome.self, from: jsonData!)
IF you have still problem let me know