UIView-Encapsulated-Layout-Width / Height Constrained to Zero

Question

There are a number of stack overflow questions about auto-layout of UITableView cells and section headers / footers that concern the UIView-Encapsulated-Layou

Answer 1

UIView doesn't have the intrinsic size hence width and height constraints needed. UIView-Encapsulated-Layout-Width and UIView-Encapsulated-Layout-Height are created by UICollectionView / UITableView initially. And later on sets the constraint constant based to the sizeForItem or heightForRowAtIndexPath delegate method. To ensure that UICollectionViewCell / UITableViewCell created in cellForItem / cellForRow method will be having the exact size.