How to create a closure inside a closure? [duplicate] - ios

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Calling Swift Closure Inside Closure
(4 answers)
Closed 4 years ago.
I am trying to create a function in Swift so I can make a repeating animation (I know you can use .repeat, but I do not want to use that). In my completion closure, I am getting an error. Here is my code so far:
import UIKit
var withDurationVar:TimeInterval = 0
var optionsVar:UIViewAnimationOptions?
var iterateVar = 0
var animationsVar:(() -> ()?)?
var completionVar:(() -> ()?)?
var numberOfIterations = 0
func repeatingAnimation(withDuration:TimeInterval, options:UIViewAnimationOptions, iterate:Int, animations:#escaping () -> (), completion:#escaping () -> ()) {
withDurationVar = withDuration
optionsVar = options
iterateVar = iterate
animationsVar = animations
completionVar = completion
}
func animationRepeat() {
UIView.animate(withDuration: withDurationVar, delay: 0, options: optionsVar!, animations: animationsVar as! () -> Void, completion: { (Finished) in
// Increase number of iterations
numberOfIterations += 1
// If it has not yet done every iteration needed
if numberOfIterations != iterateVar {
// Repeat animation
animationRepeat()
}
else {
completionVar // Where I get an error. 'Expression resolves to an unused I-value'
}
})
}
I can do this however:
func animationRepeat() {
UIView.animate(withDuration: withDurationVar, delay: 0, options: optionsVar!, animations: animationsVar as! () -> Void, completion: completionVar)
}
So how can I have the completion from my repeatingAnimation function into the completion of animationRepeat with the rest of the code as well? Thanks!

Answer 1

I have updated my code if anyone want to use it as a repeating animation function :)
import UIKit
// Make some variables to be accessed across the file
var withDurationVar:TimeInterval = 0
var optionsVar:UIViewAnimationOptions?
var iterateVar = 0
var animationsVar:(() -> ()?)?
var completionVar:(() -> ()?)?
var numberOfIterations = 0
// The function to call
func repeatingAnimation(withDuration:TimeInterval, options:UIViewAnimationOptions, iterate:Int, animations:#escaping () -> (), completion:#escaping () -> ()) {
// Set the global variables from the parameters
withDurationVar = withDuration
optionsVar = options
iterateVar = iterate
animationsVar = animations
completionVar = completion
// Has not started repeating yet
numberOfIterations = 0
// Start repeat
animationRepeatForFunction()
}
// The function which is ONLY called by the repeatingAnimation or itself, not the user
func animationRepeatForFunction() {
UIView.animate(withDuration: withDurationVar, delay: 0, options: optionsVar!, animations: {animationsVar?()}, completion: { (Finished) in
// Increase number of iterations
numberOfIterations += 1
// If it has not yet done every iteration needed
if numberOfIterations < iterateVar {
// Repeat animation
animationRepeatForFunction()
}
else {
// Perform what the user wanted to do after the repeating animation
completionVar?()
}
})
}
Call the function using repeatingAnimation(...)
The .repeat function can only really be used for infinite loops, which do not need to be stopped. In my case, I wanted to repeat a finite amount of times (terminates), so I made this custom function which can have its own .swift file.