Add the block closure to the UIButton.

UIButton+ActionBlock.swift

/// Block for addTarget
extension UIControl {
    
    public typealias UIControlActionBlock = (_ sender: UIControl) -> Void

    public class UIControlClosureWrapper {
        let owner: UIControl
        let actionBlock: UIControlActionBlock
        let event: UIControlEvents
        
        init(owner: UIControl,
             block: @escaping UIControlActionBlock,
             event: UIControlEvents) {
            self.owner = owner
            self.actionBlock = block
            self.event = event
            objc_setAssociatedObject(owner,
                                     &ActionBlockKey,
                                     self,
                                     .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
        
        @objc func fire() {
            actionBlock(owner)
        }
        
        @objc func fireOnce() {
            actionBlock(owner)
            owner.removeActionBlock()
        }
    }
    
    @discardableResult
    public func addActionBlock(fireOnce: Bool = false,
                               for event: UIControlEvents = .touchUpInside,
                               _ block: @escaping UIControlActionBlock) -> UIControl.UIControlClosureWrapper {
        let w = UIControlClosureWrapper(owner: self, block: block, event: event)
        let selector = fireOnce ? #selector(UIControlClosureWrapper.fireOnce) : #selector(UIControlClosureWrapper.fire)
        addTarget(w, action: selector, for: event)
        return w
    }
    
    public func removeActionBlock(wrapper: UIControl.UIControlClosureWrapper? = nil) {
        var w: UIControl.UIControlClosureWrapper
        if wrapper == nil {
            guard let associatedWrapper = objc_getAssociatedObject(self, &ActionBlockKey) as? UIControlClosureWrapper else { print("⚠️ UIControl -> removeActionBlock -> Can't remove action block."); return }
            w = associatedWrapper
        } else {
            w = wrapper!
        }
        
        self.removeTarget(w, action: #selector(UIControlClosureWrapper.fire), for: w.event)
        self.removeTarget(w, action: #selector(UIControlClosureWrapper.fireOnce), for: w.event)
        
        objc_removeAssociatedObjects(w)
    }
}



// or 



// MARK: - Tappabale
private var kButtonBlockAssociationKey: UInt8 = 0
public extension UIButton {
    class ClosureWrapper {
        var closure: VoidCompletion?

        init(_ closure: VoidCompletion?) {
            self.closure = closure
        }
    }

    internal var tapButtonBlock: VoidCompletion? {
        get {
            if let cw = objc_getAssociatedObject(self,
                                                 &kButtonBlockAssociationKey) as? ClosureWrapper {
                return cw.closure
            }
            return nil
        }
        set(newValue) {
            objc_setAssociatedObject(self,
                                     &kButtonBlockAssociationKey,
                                     ClosureWrapper(newValue),
                                     objc_AssociationPolicy.OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }

    /** Links UIButton tap (TouchUpInside) event to a block.

     Example Usage:

     ```
     button.tap {
     // do something
     }
     ```

     Or
     ```
     button.tap(doSomething)

     // later
     func doSomething() {
     // ...
     }
     ```

     - Returns: Itself for chaining purposes

     */
    @discardableResult
    func didTap(_ block:@escaping () -> Void) -> UIButton {
        addTarget(self, action: #selector(UIButton.tapped), for: .touchUpInside)
        tapButtonBlock = block
        return self
    }

    /** */
    @objc func tapped() {
        tapButtonBlock?()
    }
}