Decoding/parsing specific JSON with Swift - ios

Question

I am having a lot of trouble trying to decode this JSON with Swift 4.
{
"Items": [
{
"id": 1525680450507,
"animal": "bee",
"type": "insect",
"diet": [
"a",
"b",
"c"
]
}
],
"Count": 1,
"ScannedCount": 5
}
Here's where I try to decode
let decoder = JSONDecoder()
let data = try decoder.decode([Animal].self, from: data)
I have created a struct like this
struct Animal: Codable {
var id: Int
var animal: String
var type: String
var diet: [String]
}
let decoder = JSONDecoder()
let data = try decoder.decode(ItemsResponse.self, from: data)
This doesn't work. I get an error that says
"Expected to decode Array<\Any> but found a dictionary instead."
So I thought maybe I needed something like this
struct ItemsResponse: Codable {
var Items: [Animal]
var Count: Int
var ScannedCount: Int
}
But this doesn't work either. Now I get
"Expected to decode Array<\Any> but found a string/data instead."
How do I make a struct that will decode this JSON?

Answer 1

let data = try decoder.decode([Animal].self, from: data)
[Animal].self is not correct you can use it like this :
struct DataJson: Codable {
let items: [Item]
let count, scannedCount: Int
enum CodingKeys: String, CodingKey {
case items = "Items"
case count = "Count"
case scannedCount = "ScannedCount"
}
}
struct Item: Codable {
let id: Int
let animal, type: String
let diet: [String]
}
// MARK: Convenience initializers
extension DataJson {
init(data: Data) throws {
self = try JSONDecoder().decode(DataJson.self, from: 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)
}
}
extension Item {
init(data: Data) throws {
self = try JSONDecoder().decode(Item.self, from: 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)
}
}

Answer 2

Try this:
import Foundation
let json = """
{
"Items": [
{
"id": 1525680450507,
"animal": "bee",
"type": "insect",
"diet": [
"a",
"b",
"c"
]
}
],
"Count": 1,
"ScannedCount": 5
}
"""
struct Animal: Codable {
var id: Int
var animal: String
var type: String
var diet: [String]
}
struct ItemsResponse: Codable {
var Items: [Animal]
var Count: Int
var ScannedCount: Int
}
let data = try! JSONDecoder().decode(ItemsResponse.self, from: json.data(using: .utf8)!)
Of course, you should properly handle the possible failures (i.e. don't do try!, and don't force-unwrapp the json.data()! part)
But the code above works and hopefully answers your question.