How to parse JSON using Alamofire 4.7 in Swift 4 - ios

Question

I know this question was asked before, but answers were in Swift 3 and using older versions of Alamofire.
Problem: Can't figure out how to retrieve data from JSON response, mainly api_key.
Here is code for my response:
Alamofire.request(serverLink!, headers: headers).responseJSON{ response in
if response.value != nil {
//Some code to get api_key
print(response)
} else {
print("error")
}
When I print(response) I get the following:
SUCCESS: {
user = {
"api_key" = 9a13f31770b80767a57d753961acbd3a18eb1370;
"created_on" = "2010-09-30T12:57:42Z";
firstname = Paul;
id = 4;
"last_login_on" = "2018-03-27T10:15:10+03:00";
lastname = Smith;
login = admin;
mail = "admin#demo.com";
status = 1;
};
}
What I need to get is
"api_key" = 9a13f31770b80767a57d753961acbd3a18eb1370;
It could be in form of array, dict or just string containing:
9a13f31770b807...
Could someone please explain to me how to get(decode) it from this request?
EDIT
print(response.result.value):
RESPONSE: Optional({ user = { "api_key" = 9a13f31770b80767a57d753961acbd3a18eb1370; "created_on" = "2010-09-30T12:57:42Z"; firstname = Paul; id = 4; "last_login_on" = "2018-03-27T11:10:25+03:00"; lastname = Smith; login = admin; mail = "admin#demo.com"; status = 1; }; })

Answer 1

As per the docs, this is how you access the serialised JSON response:
if let json = response.result.value as? [String: Any] {
print("JSON: \(json)") // serialized json response
}
To access api_key you just need to unwrap the success and user dictionaries first and then you can access the api_key property in the user dictionary.
guard let user = json["user"] as? [String: Any],
let apiKey = user["api_key"] as? String else {
print("Failed to parse JSON")
return
}
print(apiKey)

Answer 2

When you get the response you can. use Mapper class of ObjectMapper library.
Create Model Class
import Foundation
import ObjectMapper
public final class LoginModel: Mappable, NSCoding {
// MARK: Declaration for string constants to be used to decode and also serialize.
private struct SerializationKeys {
static let status = "status"
static let login = "login"
static let firstname = "firstname"
static let id = "id"
static let lastname = "lastname"
static let mail = "mail"
static let apiKey = "api_key"
static let createdOn = "created_on"
static let lastLoginOn = "last_login_on"
}
// MARK: Properties
public var status: Int?
public var login: String?
public var firstname: String?
public var id: Int?
public var lastname: String?
public var mail: String?
public var apiKey: String?
public var createdOn: String?
public var lastLoginOn: String?
// MARK: ObjectMapper Initializers
/// Map a JSON object to this class using ObjectMapper.
///
/// - parameter map: A mapping from ObjectMapper.
public required init?(map: Map){
}
/// Map a JSON object to this class using ObjectMapper.
///
/// - parameter map: A mapping from ObjectMapper.
public func mapping(map: Map) {
status <- map[SerializationKeys.status]
login <- map[SerializationKeys.login]
firstname <- map[SerializationKeys.firstname]
id <- map[SerializationKeys.id]
lastname <- map[SerializationKeys.lastname]
mail <- map[SerializationKeys.mail]
apiKey <- map[SerializationKeys.apiKey]
createdOn <- map[SerializationKeys.createdOn]
lastLoginOn <- map[SerializationKeys.lastLoginOn]
}
/// Generates description of the object in the form of a NSDictionary.
///
/// - returns: A Key value pair containing all valid values in the object.
public func dictionaryRepresentation() -> [String: Any] {
var dictionary: [String: Any] = [:]
if let value = status { dictionary[SerializationKeys.status] = value }
if let value = login { dictionary[SerializationKeys.login] = value }
if let value = firstname { dictionary[SerializationKeys.firstname] = value }
if let value = id { dictionary[SerializationKeys.id] = value }
if let value = lastname { dictionary[SerializationKeys.lastname] = value }
if let value = mail { dictionary[SerializationKeys.mail] = value }
if let value = apiKey { dictionary[SerializationKeys.apiKey] = value }
if let value = createdOn { dictionary[SerializationKeys.createdOn] = value }
if let value = lastLoginOn { dictionary[SerializationKeys.lastLoginOn] = value }
return dictionary
}
// MARK: NSCoding Protocol
required public init(coder aDecoder: NSCoder) {
self.status = aDecoder.decodeObject(forKey: SerializationKeys.status) as? Int
self.login = aDecoder.decodeObject(forKey: SerializationKeys.login) as? String
self.firstname = aDecoder.decodeObject(forKey: SerializationKeys.firstname) as? String
self.id = aDecoder.decodeObject(forKey: SerializationKeys.id) as? Int
self.lastname = aDecoder.decodeObject(forKey: SerializationKeys.lastname) as? String
self.mail = aDecoder.decodeObject(forKey: SerializationKeys.mail) as? String
self.apiKey = aDecoder.decodeObject(forKey: SerializationKeys.apiKey) as? String
self.createdOn = aDecoder.decodeObject(forKey: SerializationKeys.createdOn) as? String
self.lastLoginOn = aDecoder.decodeObject(forKey: SerializationKeys.lastLoginOn) as? String
}
public func encode(with aCoder: NSCoder) {
aCoder.encode(status, forKey: SerializationKeys.status)
aCoder.encode(login, forKey: SerializationKeys.login)
aCoder.encode(firstname, forKey: SerializationKeys.firstname)
aCoder.encode(id, forKey: SerializationKeys.id)
aCoder.encode(lastname, forKey: SerializationKeys.lastname)
aCoder.encode(mail, forKey: SerializationKeys.mail)
aCoder.encode(apiKey, forKey: SerializationKeys.apiKey)
aCoder.encode(createdOn, forKey: SerializationKeys.createdOn)
aCoder.encode(lastLoginOn, forKey: SerializationKeys.lastLoginOn)
}
}
User this model class to map your response...
Alamofire.request(serverLink!, headers: headers).responseJSON{ response in
if let responseData = Mapper< LoginModel>().map(JSONObject: response.result.value) {
print(responseData.apiKey)
} else {
print("Fail to map data")
}
}