What is CollectionViewShelfLayout?

CollectionViewShelfLayout is a UICollectionViewLayout subclass displays its items as rows of items similar to the App Store Feature tab without a nested UITableView/UICollectionView hack. You can use a single data source for all of your contents. Each section displays its items in a row. CollectionViewShelfLayout supports collection view’s header view and footer view similar to table view’s tableHeaderView and tableFooterView also sections’ header and footer views too.