How to use Decodable in Swift? - ios

Question

I am using a free dates API in my project. I am using Decodable to parse the JSON data.
Here I created my struct:-
struct jsonStruct: Decodable {
var message: Bool?
var data: [dateData]
}
struct dateData: Decodable {
var quarter: Int?
var day: String?
var month: String?
}
This is my code to use the decoder:-
let jsonUrlString = "https://api.lrs.org/random-date-generator?lim_quarters=40&source=api-docs"
guard let url = URL(string: jsonUrlString) else { return }
URLSession.shared.dataTask(with: url) { (data, reponse, err) in
guard let data = data else { return }
print(data)
do {
let jsonData = try JSONDecoder().decode([dateData].self, from: data)
print(jsonData)
}
catch let jsonerr {
print("error serrializing error",jsonerr)
}
}.resume()
But I am getting an error in my code. It goes in the catch block only and I am getting this error in my console:-
error serrializing error typeMismatch(Swift.Array, Swift.DecodingError.Context(codingPath: [], debugDescription: "Expected to decode Array but found a dictionary instead.", underlyingError: nil))
I don't understand what I am doing wrong in my code.
API Data:-
{
messages: false,
data: {
2018-01-02: {
quarter: 1,
day: "2",
month: "1",
db: "2018-01-02",
long: "Tuesday, January 2nd, 2018",
unix: 1514876400
},

Answer 1

struct Job: Decodable {
var title: String
var salary: Float
init(title: String, salary: Float) {
self.title = title
self.salary = salary
}
enum CodingKeys: String, CodingKey {
case title, salary
}
}
struct Person: Decodable {
var job: Job
var firstName: String
var lastName: String
var age: Int
init(job: Job, firstName: String, lastName: String, age: Int) {
self.job = job
self.firstName = firstName
self.lastName = lastName
self.age = age
}
enum CodingKeys: String, CodingKey {
case job = "job_information", firstName = "firstname", lastName =
"lastname", age
}
}
let rawData = """
{
"job_information": {
"title": "iOS Developer",
"salary": 5000
},
"firstname": "John",
"lastname": "Doe",
"age": 20
}
""".data(using: .utf8)!
let person = try JSONDecoder().decode(Person.self, from: rawData)
print(person.firstName) // John
print(person.lastName) // Doe
print(person.job.title) // iOS Developer

Answer 2

You need
struct Root: Codable {
let messages: Bool
let data: [String: Datum]
}
struct Datum: Codable {
let quarter: Int
let day, month, db, long: String
let unix: Int
}
let jsonData = try JSONDecoder().decode(Root.self, from: data)
print(jsonData.data.values)
As the root of the json is a dictionary not an array , also data is a dictionary
jsonData.data.forEach {
if $0 == " 2018-01-02" {
print($1.month)
}
}