Completion Block seemingly being ignored - ios

Question

So I have a function with a completion block that handles animation and a function calling that function. During the function call the completion block is seemingly skipped over because no print lines are printed. I have tried putting the code to be executed into the main queue but it has not yielded any results. Here is how I'm calling the function:
runAnimations(past.count, currentIteration: 0, animationsArray: past, completion: {
finished in
var randomr = self.randomInRange(0,hi: 3)
println("sell")
past.append(randomr)
for i in past123{
if(past.count >= 10){
}
else{
// have tried with and without dispatch_async.. neither print little did I know
dispatch_async(dispatch_get_main_queue()) {
println("little did I know")
self.incrementGame(past)
}
}
}
})
I know it is not an issue with the past.count if statement because the sell print line is not executed either. A breakpoint at the function call simply shows it skipping over however I am aware this is due to it being in an async thread.
Here is the code for runAnimations function:
func runAnimations(numberToIterate:Int, currentIteration:Int, animationsArray : [Int], completion: ((Bool) -> Void)?) {
UIView.animateWithDuration(1, animations: {
if(animationsArray[currentIteration] == 0){
self.label.text="circle!"
//self.label.alpha = 0.0
}
else if(animationsArray[currentIteration] == 1){
self.label.text="square!"
//self.label.alpha = 0.0
}
else if(animationsArray[currentIteration] == 2){
self.label.text="triangle!"
//self.label.alpha = 0.0
}
else if(animationsArray[currentIteration] == 3){
self.label.text="star!"
//self.label.alpha = 0.0
}
}, completion: {
finished in
println("BRO")
if(currentIteration+1>=numberToIterate){
self.label.alpha = 1.0
println("ook")
}
else{
println("okies")
self.runAnimations(numberToIterate, currentIteration: currentIteration+1, animationsArray: animationsArray, completion: { finished in
})
//self.runAnimations(numberToIterate, currentIteration: currentIteration+1, animationsArray: animationsArray)
}
})
The prints in runAnimation execute properly.

Answer 1

You actually have to call the completion block, which you haven't done by doing
completion(finished)
The completion block you defined can be seen as a separate method, which you need to call. In your case you have left your block as an optional so you must do optional checking as per the standard (completion != nil, etc)
This is a very "swift" guide on a completion block in swift, which is now called a closure. Take a look: here