update to make collection less restrictive

MVMCoreUI/Atomic/Molecules/Items/CollectionItemModelProtocol.swift

@@ -8,6 +8,6 @@
 
 import Foundation
 
-public protocol CollectionItemModelProtocol: ContainerModelProtocol {
+public protocol CollectionItemModelProtocol {
     
 }

MVMCoreUI/Atomic/Molecules/Items/MoleculeCollectionItemModel.swift

@@ -9,7 +9,7 @@
 import Foundation
 
 
-@objcMembers open class MoleculeCollectionItemModel: CollectionItemModelProtocol, MoleculeModelProtocol {
+@objcMembers open class MoleculeCollectionItemModel: CollectionItemModelProtocol, ContainerModelProtocol, MoleculeModelProtocol {
     open class var identifier: String {
         return "collectionItem"
     }

MVMCoreUI/BaseClasses/CollectionViewCell.swift

@@ -8,6 +8,7 @@
 
 import Foundation
 
+/// A base collection view cell with basic mvm functionality.
 open class CollectionViewCell: UICollectionViewCell, MoleculeViewProtocol, MVMCoreViewProtocol {
 
     // Convenience helpers
@@ -44,7 +45,9 @@ open class CollectionViewCell: UICollectionViewCell, MoleculeViewProtocol, MVMCo
     }
     
     open func updateView(_ size: CGFloat) {
-        containerHelper.updateViewMargins(contentView, model: model, size: size)
+        if let model = model as? ContainerModelProtocol {
+            containerHelper.updateViewMargins(contentView, model: model, size: size)
+        }
         (molecule as? MVMCoreViewProtocol)?.updateView(size)
     }
     
@@ -63,7 +66,9 @@ open class CollectionViewCell: UICollectionViewCell, MoleculeViewProtocol, MVMCo
         }
         
         // align if needed.
-        containerHelper.set(with: model, for: molecule as? MVMCoreUIViewConstrainingProtocol)
+        if let model = model as? ContainerModelProtocol {
+            containerHelper.set(with: model, for: molecule as? MVMCoreUIViewConstrainingProtocol)
+        }
     }
     
     /// Convenience function. Adds the molecule to the view.

MVMCoreUI/BaseControllers/ProgrammaticCollectionViewController.swift

@@ -8,6 +8,7 @@
 
 import Foundation
 
+/// A base view controller with a collection view.
 @objc open class ProgrammaticCollectionViewController: ScrollingViewController {
     
     public var collectionView: UICollectionView?

MVMCoreUI/BaseControllers/ThreeLayerCollectionViewController.swift

@@ -181,35 +181,30 @@ import Foundation
     open func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForHeaderInSection section: Int) -> CGSize {
         guard let _ = topView,
             section == 0 else { return .zero }
+        
+        // Calculate the height of the header since apple doesn't support autolayout. Width is fixed, height is tall as content.
         let header = headerView ?? self.collectionView(collectionView, viewForSupplementaryElementOfKind: UICollectionView.elementKindSectionHeader, at: IndexPath(row: 0, section: section))
-
+        return header.systemLayoutSizeFitting(CGSize(width: collectionView.frame.width, height: UIView.layoutFittingExpandedSize.height), withHorizontalFittingPriority: .required, verticalFittingPriority: .fittingSizeLevel)
-        // Use this view to calculate the optimal size based on the collection view's width
-        return header.systemLayoutSizeFitting(CGSize(width: collectionView.frame.width, height: UIView.layoutFittingExpandedSize.height),
-                                 withHorizontalFittingPriority: .required, // Width is fixed
-                                       verticalFittingPriority: .fittingSizeLevel) // Height can be as large as needed
     }
     
     open func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, referenceSizeForFooterInSection section: Int) -> CGSize {
         guard let _ = bottomView,
             section == numberOfSections(in: collectionView) - 1 else { return .zero }
+        
+        // Calculate the height of the footr since apple doesn't support autolayout. Width is fixed, height is tall as content.
         let footer = footerView ?? self.collectionView(collectionView, viewForSupplementaryElementOfKind: UICollectionView.elementKindSectionFooter, at: IndexPath(row: 0, section: section))
-
+        return footer.systemLayoutSizeFitting(CGSize(width: collectionView.frame.width, height: UIView.layoutFittingExpandedSize.height), withHorizontalFittingPriority: .required, verticalFittingPriority: .fittingSizeLevel)
-        // Use this view to calculate the optimal size based on the collection view's width
-        let size = footer.systemLayoutSizeFitting(CGSize(width: collectionView.frame.width, height: UIView.layoutFittingExpandedSize.height),
-        withHorizontalFittingPriority: .required, // Width is fixed
-              verticalFittingPriority: .fittingSizeLevel) // Height can be as large as needed
-        return size
     }
     
     open func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath: IndexPath) -> UICollectionReusableView {
-        if kind == UICollectionView.elementKindSectionFooter {
+        if kind == UICollectionView.elementKindSectionFooter,
-           let footerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: footerID, for: indexPath) as! ContainerCollectionReusableView
+            let footerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: footerID, for: indexPath) as? ContainerCollectionReusableView {
             footerView.addAndContain(view: bottomView!)
             footerView.topConstraint?.constant = spaceAboveBottomView() ?? 0
             self.footerView = footerView
             return footerView
-        } else if kind == UICollectionView.elementKindSectionHeader {
+        } else if kind == UICollectionView.elementKindSectionHeader,
-            let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: headerID, for: indexPath) as! ContainerCollectionReusableView
+            let headerView = collectionView.dequeueReusableSupplementaryView(ofKind: kind, withReuseIdentifier: headerID, for: indexPath) as? ContainerCollectionReusableView {
             headerView.addAndContain(view: topView!)
             headerView.bottomConstraint?.constant = spaceBelowTopView() ?? 0
             self.headerView = headerView