Action for header in UICollectionView IOS

Question

I have different number of headers in a collection in my code and when I click a header each header has different actions. If I select a cell, - (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath method is called. So, is there any delegate method which is called when any supplementary view is selected?

Answer 1

Here is @Geet's answer for Swift 5. There are only 9 simple steps using a delegation

// 1. create a protocol outside of your headerView class
protocol YourHeaderViewDelegate: class {

    // 2. create a function that will do something when the header is tapped
    func doSomething()
}

class YourHeaderView: UICollectionReusableView {

    // 3. inside the headerView set a property named delegate of type YourHeaderViewDelegate? and make sure it's **weak**
    weak var delegate: YourHeaderViewDelegate?

    override init(frame: CGRect) {
        super.init(frame: frame)

        // 4. add a tapGesture to your headerView
        let tapGesture = UITapGestureRecognizer(target: self, action: #selector(headerViewTapped))
        addGestureRecognizer(tapGesture)
    }

    // 5. inside the selector method for the tapGestureRecognizer call the property and then call the doSomething method
    @objc func headerViewTapped() {

        delegate?.doSomething()
    }
}

// 6. make sure the class with the headerView's collectionView conforms to YourHeaderViewDelegate
class ClassWithCollectionView: YourHeaderViewDelegate {

    // 7. inside the class with your collectionView when you create the headerView make to set the delegate as self
    func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
        let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: "headerViewId", for: indexPath) as! YourHeaderView
        
        // 8. *** set this to self ***
        headerView.delegate = self
        
        return headerView
    }

    // 9. since your class conforms to the YourHeaderViewDelegate method when you tap the headerView this function will get called
    func doSomething() {

        print("hello!")
    }
}