Trouble delaying function with variables passed to it in swift 4

Question

I'm very new to swift and am having trouble with calling this function again on the 6th line after a delay, Xcode is telling me that

Argument of '#selector' does not refer to an '@objc' method, property, or initializer

I know what the problem is and have tried searching around but haven't been able to make anything work.

@objc func attemptToIdentify(_ user: String) {
    if manager.status == .connected {
        socket.emit("identify", user) //This functions correctly
    } else {
        print(manager.status, "... will attempt subscription in 1 second")
        self.perform(#selector(attemptToIdentify(user)), with: nil, afterDelay: 1)
    }
}

Using matt's suggestions I changed line 6 to 'self.perform(#selector(attemptToIdentify), with: user, afterDelay: 1)' and everything is working now — b.stevens.photo, Oct 18 '18 at 21:30
Great but I would still suggest that using `perform:with:afterDelay:` at all is a bad idea. There is a Swift way to do a delay and that's not it. — matt, Oct 18 '18 at 21:34

score 2 · Accepted Answer · answered Oct 18 '18 at 21:24

2

The problem is that attemptToIdentify(user) is a call. This is not the place for a call; you need a selector, i.e. the name of a function. So just put attemptToIdentify. If you need to pass something, you can pass it in the with parameter.

Even better, don't use perform:afterDelay: at all. If the idea is to add a delay to a call, just use asyncAfter (or my delay encapsulation of it).

answered Oct 18 '18 at 21:24

matt

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I see. Updated the code using your suggestions and it works now, thank you! – b.stevens.photo Oct 18 '18 at 21:29

Trouble delaying function with variables passed to it in swift 4

1 Answers1