How to use PUT request in Alamofire

Question

I am new in swift and I am also trying to use Alamofire to call data from API. I am quite puzzled on how I will use the PUT Request to update data. I've read some solutions here in SO but I don't know how I will apply on my app. I am creating an Event App, the scenario should be, when the participant clicked the Check In Button, it will update the registered_flag to true meaning the participant will marked as Registered and the button will be changed to Check Out. I really don't know if my API Service is correct or not. Hope you could help me. Thank you so much.

JSON of the Event Participant Where in the registered_flag should be updated once checkInOutButton

{
    "event_name": "Q & A",
    "event_participants": [
        {
            "participant_id": "70984656-92bc-4c36-9314-2c741f068523",
            "employee_number": null,
            "last_name": "Surname",
            "first_name": "FirstName",
            "middle_name": null,
            "display_name": "Surname, FirstName ",
            "department_name": "Medical Informatics",
            "position_name": "Application Developer",
            "registered_flag": true,
            "registered_datetime": "2018-09-13T08:54:40.150",
            "registration_type": 1,
            "delete_flag": false,
            "manual_reg_flag": false,
            "out_flag": false,
            "out_datetime": null,
            "classification": 6,
            "others": "Guest"
          }
        }

JSON to update for check in

{
   "registered_flag": true,
   "registration_type": 1
}

updateType

enum UpdateParticipantType: String {

case checkIn = "Check In"
case checkOut = "Check Out"
}

APIService for UpdateParticipant

 func updateParticipant(updateType: UpdateParticipantType,
                       participantID: String,
                       successBlock: @escaping ([Attendee]) -> Void,
                       failureBlock: @escaping (Error) -> Void)

{

   let updateParticipantURL = URL(string: "\(REGISTER_PARTICIPANT_URL)/\(updateType)/\(participantID)")

    Alamofire.request(updateParticipantURL!, method: .put).responseJSON { (response) in
        print(response)

        if let error = response.error
        {
            failureBlock(error)
            print(error)
            return
        }

        if let jsonArray = response.result.value as? [[String : Any]] {
            for anItem in jsonArray {
                if let eventparticipants = anItem["event_participants"] as? [[String : Any]] {
                    var extractedAttendees = [Attendee]()
                    for participants in eventparticipants{
                        let success = Attendee.init(JSON: participants)
                        extractedAttendees.append(success!)
                    }
                    successBlock(extractedAttendees)
                }
            }
        }
    }
}

Answer 1

As per Alamofire documentation:

let parameters: Parameters = [
    "foo": "bar",
    "baz": ["a", 1],
    "qux": [
        "x": 1,
        "y": 2,
        "z": 3
    ]
 ]

Alamofire.request("https://httpbin.org/post", method: .post, parameters: parameters)

For a given json

 {
    "registered_flag": true,
    "registration_type": 1
 }

let parameters: Parameters = [
     "registered_flag": true
     "registration_type": 1
 ]