How do you declare an optional closure as a property in Swift?
I am using this code:
var respondToButton:(sender: UIButton) -> Bool
but the compiler complains that the property is not initialized by the end of the initializer. I believe I can solve this issue by declaring the var as an optional, however, I can not find the correct syntax.
How do I declare this closure property as an optional?
I believe you just need to wrap the closure type in parenthesis, like so:
var respondToButton:((sender: UIButton) -> Bool)?
Alternatively if this is a closure type you're going to use often you can create a typealias to make it more readable:
typealias buttonResponder = (sender: UIButton) -> Bool
then in your class:
var respondToButton:buttonResponder?
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