How to limit function to once in every x SWIFT - json

Question

so I have made a comments option on my app which lets the users comment something on posts. It is directly referenced and sends info from the string to the api endpoint. That works, now I was wondering if there was a way to limit the number of essentially requests to the API so users can send comments once every minute per say
TextField("Comment...", text: $comment) { editingChanged in
} onCommit: {
validate()
showsAlert = !isValid
if isValid{
viewModel.sendComment(nickname: nickname, body: comment) {
self.comment = ""
}
}
}
}
.padding()
.frame(width: UIScreen.main.bounds.width, height: 80)
.ignoresSafeArea(.keyboard, edges: .bottom)
It would help me reduce spam on the comments and would be a life saver

Answer 1

You can create a simple Swift class to control the time.
public class Time_Control:Thread{
var wait_time:Int //In seconds
public var can_send:Bool = true
init(_ wait_time:Int) {
self.wait_time = wait_time
}
public override func start() {
super.start()
self.can_send = false
Thread.self.sleep(forTimeInterval: TimeInterval(self.wait_time))
self.can_send = true
}
}
Then you can use this object in any part of your code to control time between events. For this, first have a variable to store the object of the class Time_Control, for example, var control:Time_Control = Time_Control(0). After that, each time you want to control the time of something just do the following:
func send_message(){
if control.can_send{
//Start the time controller with 60 seconds
control = Time_Control(60)
control.start()
//Let the user send message
//... your code
}else{
//Don't let the user send message
//...
}
}
When the user interacts with your UI, you can call the function send_message(). It will allow the user to send a message every 60 seconds.

Answer 2

In Swift you can get the Unix timestamp of the current moment using:
let currentUnixTimestamp = Date().timeIntervalSince1970
Unix time simply counts the seconds that have elapsed since 1 Jan, 1970 00:00:00 UTC. See Wikipedia to learn more.
Using this, you could create a field in which you save the current timestamp every time a comment is sent and then check the current time against the saved timestamp. If your viewModel is of a class type, which I assume it is, it is the perfect place to put this code. It might look like this:
class ViewModel {
// How many seconds to wait before the user can comment again
private static let cooldownInSeconds = 60
private var lastSendTimestamp: Int? = nil
func sendComment(nickname: String, body: String) {
let currentTime = Date().timeIntervalSince1970
if currentTime >= (lastSendTimestamp ?? Int.min) + ViewModel.cooldownInSeconds {
lastSendTimestamp = currentTime
// Send comment here
} else {
// Cannot send comment because cooldown has not run out
}
}
}
Note that putting the variable in structs (like your View) will not work well, due to their immutable nature.