Swift: Help For Json parsing codeable/decodable - swift

Question

I am new to iOS, and want to parse the JSON using Decodable but cant get through this, how should I work this out?
The view controller where I am trying to parse the data
class ViewController: UIViewController {
var servers = [Server]()
let apiUrl = "https://someurl/api/dashboard"
override func viewDidLoad() {
super.viewDidLoad()
guard let url = URL(string: self.apiUrl) else { return }
getDataFrom(url)
}
fileprivate func getDataFrom(_ url: URL) {
URLSession.shared.dataTask(with: url){ (data, response, error) in
guard let data = data else { return }
do {
let apiResponse = try JSONDecoder().decode(Server.self, from: data)
print(apiResponse)
} catch let jsonError {
print(jsonError)
}
}.resume()
}
}
The Server.swift file where I am confirming to the decodable protocol
struct Server: Decodable {
let current_page: Int
let data: [ServerData]
let first_page_url: String
}
struct ServerData: Decodable {
let hostname: String
let ipaddress: String
let customer: [Customer]
let latest_value: [LatestValue]
}
struct Customer: Decodable {
let name: String
let contact_person :String
let email: String
}
struct LatestValue: Decodable {
let systemuptime: String
let memtotal: Float
let memfree: Double
let loadaverage: Float
}
No value associated with key CodingKeys I get this error,
The response from the server
{
"servers": {
"current_page": 1,
"data": [
{
"hostname": "johndoes",
"ipaddress": "10.0.2.99",
"id": 7,
"latest_value_id": 1130238,
"customers": [
{
"name": "Jane Doe",
"contact_person": "John Doe",
"id": 2,
"email": "john.#example.com",
"pivot": {
"server_id": 7,
"customer_id": 2
}
}
],
"latest_value": {
"id": 1130238,
"server_id": 7,
"systemuptime": "80days:10hours:23minutes",
"memtotal": 3.7,
"memfree": 1.6400000000000001,
"loadaverage": 2.25,
"disktotal": {
"dev-mapper-centos-root_disktotal": "38",
"dev-mapper-proquote-xfs-lvm_disktotal": "200"
},
"diskused": "{\"dev-mapper-centos-root_diskused\":\"16\",\"dev-mapper-proquote-xfs-lvm_diskused\":\"188\"}",
"custom_field": "[]",
"additional_attributes": {
"fathom": {
"name": "fathom",
"status": 1
},
"trenddb": {
"name": "trenddb",
"status": 1
},
"trendwi": {
"name": "trendwi",
"status": 1
},
"appsrv": {
"name": "appsrv",
"status": 1
}
},
"created_at": "2019-06-15 02:25:02",
"updated_at": "2019-06-15 02:25:02"
}
}
]
},
"message": "Success"
}

Answer 1

You seem to have few different errors in your data structure.
First of all, you are trying to decode Server while your json has servers inside a dict {"servers": ... }, So use a parent root object for it.
Your latest_value inside ServerData is defined as array, while it should be LatestValue struct not [LatestValue].
There is no first_page_url element in your json, but your Server struct has the property, make it optional, so that JSONDecoder decodes it only if it is present.
Here is your refined data models.
struct Response: Decodable {
let servers: Server
}
struct Server: Decodable {
let current_page: Int
let data: [ServerData]
let first_page_url: String?
}
struct ServerData: Decodable {
let hostname: String
let ipaddress: String
let customers: [Customer]
let latest_value: LatestValue
}
struct Customer: Decodable {
let name: String
let contact_person :String
let email: String
}
struct LatestValue: Decodable {
let systemuptime: String
let memtotal: Float
let memfree: Double
let loadaverage: Float
}
And decode Response instead of decoding Server, like so,
do {
let apiResponse = try JSONDecoder().decode(Response.self, from: data)
let server = apiResponse.server // Here is your server struct.
print(server)
} catch let jsonError {
print(jsonError)
}