add type check error logic. expand to replacement to the rest of parent molecules. lift full tree replacement to the template.

MVMCoreUI.xcodeproj/project.pbxproj

@@ -168,6 +168,7 @@
 		526A265E240D200500B0D828 /* ListTwoColumnCompareChanges.swift in Sources */ = {isa = PBXBuildFile; fileRef = 526A265D240D200500B0D828 /* ListTwoColumnCompareChanges.swift */; };
 		52B201D224081CFB00D2011E /* ListLeftVariableRadioButtonAndPaymentMethod.swift in Sources */ = {isa = PBXBuildFile; fileRef = 52B201D024081CFB00D2011E /* ListLeftVariableRadioButtonAndPaymentMethod.swift */; };
 		52B201D324081CFB00D2011E /* ListLeftVariableRadioButtonAndPaymentMethodModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 52B201D124081CFB00D2011E /* ListLeftVariableRadioButtonAndPaymentMethodModel.swift */; };
+		5823ADF62AB0F7BA006045A7 /* ReplacementMoleculeBehavior.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5823ADF52AB0F7BA006045A7 /* ReplacementMoleculeBehavior.swift */; };
 		8D070BB0241B56530099AC56 /* ListRightVariableTotalDataModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8D070BAF241B56530099AC56 /* ListRightVariableTotalDataModel.swift */; };
 		8D070BB2241B56AD0099AC56 /* ListRightVariableTotalData.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8D070BB1241B56AD0099AC56 /* ListRightVariableTotalData.swift */; };
 		8D084AD02410BF4800951227 /* ListOneColumnFullWidthTextBodyTextModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 8D084ACF2410BF4800951227 /* ListOneColumnFullWidthTextBodyTextModel.swift */; };
@@ -754,6 +755,7 @@
 		526A265D240D200500B0D828 /* ListTwoColumnCompareChanges.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ListTwoColumnCompareChanges.swift; sourceTree = "<group>"; };
 		52B201D024081CFB00D2011E /* ListLeftVariableRadioButtonAndPaymentMethod.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ListLeftVariableRadioButtonAndPaymentMethod.swift; sourceTree = "<group>"; };
 		52B201D124081CFB00D2011E /* ListLeftVariableRadioButtonAndPaymentMethodModel.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = ListLeftVariableRadioButtonAndPaymentMethodModel.swift; sourceTree = "<group>"; };
+		5823ADF52AB0F7BA006045A7 /* ReplacementMoleculeBehavior.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ReplacementMoleculeBehavior.swift; sourceTree = "<group>"; };
 		8D070BAF241B56530099AC56 /* ListRightVariableTotalDataModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ListRightVariableTotalDataModel.swift; sourceTree = "<group>"; };
 		8D070BB1241B56AD0099AC56 /* ListRightVariableTotalData.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ListRightVariableTotalData.swift; sourceTree = "<group>"; };
 		8D084ACF2410BF4800951227 /* ListOneColumnFullWidthTextBodyTextModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ListOneColumnFullWidthTextBodyTextModel.swift; sourceTree = "<group>"; };
@@ -1390,6 +1392,7 @@
 				D23A900826125FFB007E14CE /* GetContactBehavior.swift */,
 				D270E5662642F77300CDBED2 /* AddRemoveMoleculeBehavior.swift */,
 				22B678F829E7944E00CF4196 /* GetNotificationAuthStatusBehavior.swift */,
+				5823ADF52AB0F7BA006045A7 /* ReplacementMoleculeBehavior.swift */,
 			);
 			path = Behaviors;
 			sourceTree = "<group>";
@@ -2752,6 +2755,7 @@
 				525239C02407BCFF00454969 /* ListTwoColumnPriceDetailsModel.swift in Sources */,
 				D2E2A99A23D8D6B4000B42E6 /* HeadlineBodyButtonModel.swift in Sources */,
 				D202AFE6242A6A9C00E5BEDF /* UICollectionViewScrollPosition+Extension.swift in Sources */,
+				5823ADF62AB0F7BA006045A7 /* ReplacementMoleculeBehavior.swift in Sources */,
 				D20F3B44252E00E4004B3F56 /* PageProtocol.swift in Sources */,
 				AA37CBD3251907200027344C /* StarsModel.swift in Sources */,
 				8D084AD22410BF7600951227 /* ListOneColumnFullWidthTextBodyText.swift in Sources */,

MVMCoreUI/Atomic/Molecules/DesignedComponents/Headers/H1/HeadersH1ButtonModel.swift

@@ -20,6 +20,11 @@ public class HeadersH1ButtonModel: HeaderModel, MoleculeModelProtocol, ParentMol
         [headlineBody, buttons]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool {
+        return try replaceChildMolecule(at: &headlineBody, with: molecule)
+        || replaceChildMolecule(at: &buttons, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/Headers/H1/HeadersH1LandingPageHeaderModel.swift

@@ -24,6 +24,15 @@ public class HeadersH1LandingPageHeaderModel: HeaderModel, MoleculeModelProtocol
         [headline, headline2, subHeadline, body, link, buttons]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool {
+        return try replaceChildMolecule(at: &headline, with: molecule)
+        || replaceChildMolecule(at: &headline2, with: molecule)
+        || replaceChildMolecule(at: &subHeadline, with: molecule)
+        || replaceChildMolecule(at: &body, with: molecule)
+        || replaceChildMolecule(at: &link, with: molecule)
+        || replaceChildMolecule(at: &buttons, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/Headers/H1/HeadersH1NoButtonsBodyTextModel.swift

@@ -20,6 +20,10 @@ public class HeadersH1NoButtonsBodyTextModel: HeaderModel, MoleculeModelProtocol
         [headlineBody]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headlineBody, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/Headers/H2/HeadersH2ButtonsModel.swift

@@ -22,6 +22,11 @@ public class HeadersH2ButtonsModel: HeaderModel, MoleculeModelProtocol, ParentMo
         [headlineBody, buttons]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headlineBody, with: molecule)
+        || replaceChildMolecule(at: &buttons, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/Headers/H2/HeadersH2CaretLinkModel.swift

@@ -19,6 +19,11 @@ public class HeadersH2CaretLinkModel: HeaderModel, MoleculeModelProtocol, Parent
         [headlineBody, caretLink]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headlineBody, with: molecule)
+        || replaceChildMolecule(at: &caretLink, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/Headers/H2/HeadersH2LinkModel.swift

@@ -21,6 +21,11 @@ public class HeadersH2LinkModel: HeaderModel, MoleculeModelProtocol, ParentMolec
         [headlineBody, link]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headlineBody, with: molecule)
+        || replaceChildMolecule(at: &link, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/Headers/H2/HeadersH2NoButtonsBodyTextModel.swift

@@ -21,6 +21,10 @@ public class HeadersH2NoButtonsBodyTextModel: HeaderModel, MoleculeModelProtocol
         [headlineBody]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headlineBody, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/Headers/H2/HeadersH2PricingTwoRowsModel.swift

@@ -25,6 +25,17 @@ public class HeadersH2PricingTwoRowsModel: HeaderModel, MoleculeModelProtocol, P
         [headline, body, subBody, body2, subBody2, body3, subBody3].compactMap({$0})
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headline, with: molecule)
+        || replaceChildMolecule(at: &body, with: molecule)
+        || replaceChildMolecule(at: &subBody, with: molecule)
+        || replaceChildMolecule(at: &body2, with: molecule)
+        || replaceChildMolecule(at: &body2, with: molecule)
+        || replaceChildMolecule(at: &subBody2, with: molecule)
+        || replaceChildMolecule(at: &body3, with: molecule)
+        || replaceChildMolecule(at: &subBody3, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/Headers/H2/HeadersH2TinyButtonModel.swift

@@ -22,6 +22,11 @@ public class HeadersH2TinyButtonModel: HeaderModel, MoleculeModelProtocol, Paren
         [headlineBody, button]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headlineBody, with: molecule)
+        || replaceChildMolecule(at: &button, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/List/LeftVariable/ListLeftVariableCheckboxBodyTextModel.swift

@@ -20,6 +20,11 @@ open class ListLeftVariableCheckboxBodyTextModel: ListItemModel, MoleculeModelPr
          [checkbox, headlineBody]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &checkbox, with: molecule)
+        || replaceChildMolecule(at: &headlineBody, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/List/LeftVariable/ListLeftVariableIconAllTextLinksModel.swift

@@ -20,6 +20,11 @@ public class ListLeftVariableIconAllTextLinksModel: ListItemModel, MoleculeModel
         return [image, eyebrowHeadlineBodyLink]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &image, with: molecule)
+        || replaceChildMolecule(at: &eyebrowHeadlineBodyLink, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Method
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/List/LeftVariable/ListLeftVariableIconWithRightCaretAllTextLinksModel.swift

@@ -21,6 +21,12 @@ public class ListLeftVariableIconWithRightCaretAllTextLinksModel: ListItemModel,
         return [image, eyebrowHeadlineBodyLink, rightLabel]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &image, with: molecule)
+        || replaceChildMolecule(at: &eyebrowHeadlineBodyLink, with: molecule)
+        || replaceChildMolecule(at: &rightLabel, with: molecule)
+    }
+    
     //-----------------------------------------------------
     // MARK: - Methods
     //-----------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/List/LeftVariable/ListLeftVariableIconWithRightCaretBodyTextModel.swift

@@ -21,6 +21,12 @@ public class ListLeftVariableIconWithRightCaretBodyTextModel: ListItemModel, Par
         [image, headlineBody, rightLabel]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &image, with: molecule)
+        || replaceChildMolecule(at: &headlineBody, with: molecule)
+        || replaceChildMolecule(at: &rightLabel, with: molecule)
+    }
+    
     //-----------------------------------------------------
     // MARK: - Methods
     //-----------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/List/LeftVariable/ListLeftVariableIconWithRightCaretModel.swift

@@ -21,6 +21,12 @@ public class ListLeftVariableIconWithRightCaretModel: ListItemModel, ParentMolec
         return [image, leftLabel, rightLabel]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &image, with: molecule)
+        || replaceChildMolecule(at: &leftLabel, with: molecule)
+        || replaceChildMolecule(at: &rightLabel, with: molecule)
+    }
+    
     //-----------------------------------------------------
     // MARK: - Methods
     //-----------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/List/LeftVariable/ListLeftVariableRadioButtonBodyTextModel.swift

@@ -20,9 +20,9 @@ open class ListLeftVariableRadioButtonBodyTextModel: ListItemModel, ParentMolecu
         [radioButton, headlineBody]
     }
     
-    public func replaceChildMolecule(with replacementMolecule: MoleculeModelProtocol) -> Bool {
-        return replace(childMolecule: &radioButton, with: replacementMolecule)
-            || replace(childMolecule: &headlineBody, with: replacementMolecule)
+    public func replaceChildMolecule(with replacementMolecule: MoleculeModelProtocol) throws -> Bool {
+        return try replaceChildMolecule(at: &radioButton, with: replacementMolecule)
+        || replaceChildMolecule(at: &headlineBody, with: replacementMolecule)
     }
     
     //-----------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/List/OneColumn/ListOneColumnFullWidthTextBodyTextModel.swift

@@ -39,6 +39,10 @@ public class ListOneColumnFullWidthTextBodyTextModel: ListItemModel, MoleculeMod
         return [headlineBody]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headlineBody, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Keys
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/List/RightVariable/ListRightVariableButtonAllTextAndLinksModel.swift

@@ -40,6 +40,11 @@ public class ListRightVariableButtonAllTextAndLinksModel: ListItemModel, Molecul
         return [button, eyebrowHeadlineBodyLink]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &button, with: molecule)
+        || replaceChildMolecule(at: &eyebrowHeadlineBodyLink, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Keys
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/List/RightVariable/ListRightVariableRightCaretAlltextAndLinksModel.swift

@@ -20,6 +20,11 @@ public class ListRightVariableRightCaretAllTextAndLinksModel: ListItemModel, Par
         [rightLabel, eyebrowHeadlineBodyLink]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &rightLabel, with: molecule)
+        || replaceChildMolecule(at: &eyebrowHeadlineBodyLink, with: molecule)
+    }
+    
     //-----------------------------------------------------
     // MARK: - Methods
     //-----------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/LockUps/TitleLockupModel.swift

@@ -64,6 +64,12 @@ public class TitleLockupModel: MoleculeModelProtocol, ParentMoleculeModelProtoco
         [eyebrow, title, subTitle].compactMap { (molecule: MoleculeModelProtocol?) in molecule }
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &eyebrow, with: molecule)
+        || replaceChildMolecule(at: &title, with: molecule)
+        || replaceChildMolecule(at: &subTitle, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/SectionDividers/OneColumn/ListOneColumnFullWidthTextDividerSubsectionModel.swift

@@ -22,6 +22,11 @@ public class ListOneColumnFullWidthTextDividerSubsectionModel: ListItemModel, Mo
         [headline, body].compactMap({$0})
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headline, with: molecule)
+        || replaceChildMolecule(at: &body, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/SectionDividers/OneColumn/ListOneColumnTextWithWhitespaceDividerShortModel.swift

@@ -22,6 +22,11 @@ public class ListOneColumnTextWithWhitespaceDividerShortModel: ListItemModel, Mo
         [headline, body].compactMap({$0})
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headline, with: molecule)
+        || replaceChildMolecule(at: &body, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/DesignedComponents/SectionDividers/OneColumn/ListOneColumnTextWithWhitespaceDividerTallModel.swift

@@ -22,6 +22,11 @@ public class ListOneColumnTextWithWhitespaceDividerTallModel: ListItemModel, Mol
         [headline, body].compactMap({$0})
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &headline, with: molecule)
+        || replaceChildMolecule(at: &body, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/HorizontalCombinationViews/TwoButtonViewModel.swift

@@ -24,6 +24,11 @@ public class TwoButtonViewModel: ParentMoleculeModelProtocol {
         return [primaryButton, secondaryButton].compactMap { $0 }
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &primaryButton, with: molecule)
+        || replaceChildMolecule(at: &secondaryButton, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Keys
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/LeftRightViews/CornerLabelsModel.swift

@@ -18,10 +18,19 @@ public class CornerLabelsModel: ParentMoleculeModelProtocol {
     public var bottomLeftLabel: LabelModel?
     public var bottomRightLabel: LabelModel?
     public var molecule: MoleculeModelProtocol?
+    
     public var children: [MoleculeModelProtocol] {
         [molecule, topLeftLabel, topRightLabel, bottomLeftLabel, bottomRightLabel].compactMap { $0 }
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &self.molecule, with: molecule)
+        || replaceChildMolecule(at: &topLeftLabel, with: molecule)
+        || replaceChildMolecule(at: &topRightLabel, with: molecule)
+        || replaceChildMolecule(at: &bottomLeftLabel, with: molecule)
+        || replaceChildMolecule(at: &bottomRightLabel, with: molecule)
+    }
+    
     public init(with molecule: MoleculeModelProtocol?) {
         self.molecule = molecule
     }

MVMCoreUI/Atomic/Molecules/OtherContainers/MoleculeContainerModel.swift

@@ -20,6 +20,10 @@ open class MoleculeContainerModel: ContainerModel, MoleculeContainerModelProtoco
         return [molecule]
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &self.molecule, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Codec
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/OtherContainers/MoleculeContainerProtocol.swift

@@ -16,5 +16,9 @@ public extension MoleculeContainerModelProtocol {
     var children: [MoleculeModelProtocol] {
         return [molecule]
     }
+    
+    func replaceMolecule(with replacementMolecule: MoleculeModelProtocol) throws -> Bool {
+        return try replaceChildMolecule(at: &molecule, with: replacementMolecule)
+    }
 
 }

MVMCoreUI/Atomic/Molecules/VerticalCombinationViews/EyebrowHeadlineBodyLinkModel.swift

@@ -25,6 +25,13 @@ public class EyebrowHeadlineBodyLinkModel: MoleculeModelProtocol, ParentMolecule
         [eyebrow, headline, body, link].compactMap { (molecule: MoleculeModelProtocol?) in molecule }
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(at: &eyebrow, with: molecule)
+        || replaceChildMolecule(at: &headline, with: molecule)
+        || replaceChildMolecule(at: &body, with: molecule)
+        || replaceChildMolecule(at: &link, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Molecules/VerticalCombinationViews/HeadlineBodyModel.swift

@@ -24,9 +24,9 @@
         [headline, body].compactMap { $0 }
     }
     
-    public func replaceChildMolecule(with replacementMolecule: MoleculeModelProtocol) -> Bool {
-        return replace(childMolecule:&headline, with: replacementMolecule)
-        || replace(childMolecule:&body, with: replacementMolecule)
+    public func replaceChildMolecule(with replacementMolecule: MoleculeModelProtocol) throws -> Bool {
+        return try replaceChildMolecule(at:&headline, with: replacementMolecule)
+        || replaceChildMolecule(at:&body, with: replacementMolecule)
     }
     
     //--------------------------------------------------

MVMCoreUI/Atomic/Organisms/Carousel/CarouselModel.swift

@@ -180,4 +180,8 @@ extension CarouselModel {
         return molecules
     }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(in: &molecules, with: molecule)
+    }
+    
 }

MVMCoreUI/Atomic/Organisms/StackModel.swift

@@ -21,22 +21,6 @@
     public var spacing: CGFloat = Padding.Four
     public var useStackSpacingBeforeFirstItem = false
     
-    public var children: [MoleculeModelProtocol] {
-        return molecules
-    }
-    
-    public func replaceChildMolecule(with replacementMolecule: MoleculeModelProtocol) -> Bool {
-        // IDEALLY:
-        //return replace(inChildMolecules: &molecules, with: replacementMolecule)
-        
-        guard let replacementMolecule = replacementMolecule as? StackItemModelProtocol & MoleculeModelProtocol else { return false }
-        guard let matchingIndex = molecules.firstIndex(where: { molecule in
-            molecule.id == replacementMolecule.id
-        }) else { return false }
-        molecules[matchingIndex] = replacementMolecule
-        return true
-    }
-    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Organisms/StackModelProtocol.swift

@@ -19,4 +19,8 @@ extension StackModelProtocol {
     
     public var children: [MoleculeModelProtocol] { return molecules }
     
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool  {
+        return try replaceChildMolecule(in: &molecules, with: molecule)
+    }
+    
 }

MVMCoreUI/Atomic/Protocols/ModelProtocols/ParentMoleculeModelProtocol.swift

@@ -8,11 +8,44 @@
 
 import Foundation
 
-public protocol ParentMoleculeModelProtocol: MoleculeModelProtocol, AnyObject {
+public protocol ParentModelProtocol: MoleculeTreeTraversalProtocol, AnyObject {
     
     var children: [MoleculeModelProtocol] { get }
     
-    func replaceChildMolecule(with molecule: MoleculeModelProtocol) -> Bool
+    func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool
+}
+
+public extension ParentModelProtocol {
+    /// Top level test to replace child molecules. Each parent molecule should attempt to replace.
+    func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool { return false }
+    
+    /// Helper function for replacing molecules.
+    func replaceChildMolecule<T>(at childMolecule: inout T, with replacementMolecule: MoleculeModelProtocol) throws -> Bool {
+        guard let childIdMolecule = childMolecule as? MoleculeModelProtocol else { return false }
+        if childIdMolecule.id == replacementMolecule.id {
+            guard let replacementMolecule = replacementMolecule as? T else {
+                throw MolecularError.error("Molecular replacement '\(replacementMolecule.id)' does not type match \(type(of: T.self)) of \(type(of: self))")
+            }
+            childMolecule = replacementMolecule
+            return true
+        }
+        return false
+    }
+    
+    func replaceChildMolecule<T>(in molecules: inout [T], with replacementMolecule: MoleculeModelProtocol) throws -> Bool {
+        guard let moleculeIdModels = molecules as? [MoleculeModelProtocol], let matchingIndex = moleculeIdModels.firstIndex(where: {
+            $0.id == replacementMolecule.id
+        }) else { return false }
+        guard let replacementMolecule = replacementMolecule as? T else {
+            throw MolecularError.error("Molecular replacement '\(replacementMolecule.id)' does not type match \(type(of: T.self)) of \(type(of: self))")
+        }
+        molecules[matchingIndex] = replacementMolecule
+        return true
+    }
+}
+
+public protocol ParentMoleculeModelProtocol: ParentModelProtocol, MoleculeModelProtocol {
+    
 }
 
 public extension ParentMoleculeModelProtocol {
@@ -56,33 +89,4 @@ public extension ParentMoleculeModelProtocol {
         }
         // if options == .leafOnly don't call on self.
     }
-    
-    /// Top level test to replace child molecules. Each parent molecule should attempt to replace.
-    func replaceChildMolecule(with molecule: MoleculeModelProtocol) -> Bool { return false }
-    
-    /// Helper function for replacing molecules.
-    func replace<T: MoleculeModelProtocol>(childMolecule: inout T?, with replacementMolecule: MoleculeModelProtocol) -> Bool {
-        if childMolecule != nil, childMolecule?.id == replacementMolecule.id, let newHeadline = replacementMolecule as? T {
-            childMolecule = newHeadline
-            return true
-        }
-        return false
-    }
-    
-    func replace<T: MoleculeModelProtocol>(childMolecule: inout T, with replacementMolecule: MoleculeModelProtocol) -> Bool {
-        if childMolecule.id == replacementMolecule.id, let newHeadline = replacementMolecule as? T {
-            childMolecule = newHeadline
-            return true
-        }
-        return false
-    }
-    
-    func replace<T>(inChildMolecules molecules: inout [T], with replacementMolecule: MoleculeModelProtocol) -> Bool where T: MoleculeModelProtocol {
-        guard let replacementMolecule = replacementMolecule as? T else { return false }
-        guard let matchingIndex = molecules.firstIndex(where: { molecule in
-            molecule.id == replacementMolecule.id
-        }) else { return false }
-        molecules[matchingIndex] = replacementMolecule
-        return true
-    }
 }

MVMCoreUI/Atomic/Protocols/ModelProtocols/TemplateModelProtocol.swift

@@ -7,13 +7,17 @@
 //
 
 
-public protocol TemplateModelProtocol: PageModelProtocol, ModelProtocol, MoleculeTreeTraversalProtocol {
+public protocol TemplateModelProtocol: PageModelProtocol, ModelProtocol, MoleculeTreeTraversalProtocol, ParentModelProtocol {
     var template: String { get }
     var rootMolecules: [MoleculeModelProtocol] { get }
 }
 
 public extension TemplateModelProtocol {
     
+    var children: [MoleculeModelProtocol] {
+        return rootMolecules
+    }
+    
     var template: String {
         get { return Self.identifier }
     }
@@ -33,4 +37,28 @@ public extension TemplateModelProtocol {
     func depthFirstTraverse(options: TreeTraversalOptions, depth: Int, onVisit: (Int, MoleculeModelProtocol, inout Bool) -> Void) {
         return rootMolecules.depthFirstTraverse(options: options, depth: depth, onVisit: onVisit)
     }
+    
+    func replaceMolecule(with replacementMolecule: MoleculeModelProtocol) throws -> Bool {
+        // Attempt root level replacement on the template model first.
+        if try self.replaceChildMolecule(with: replacementMolecule) {
+            return true
+        }
+        
+        var didReplaceMolecule = false
+        var possibleError: Error?
+        // Dive into each root thereafter.
+        depthFirstTraverse(options: .parentFirst, depth: 0) { depth, molecule, stop in
+            guard let parentMolecule = molecule as? ParentMoleculeModelProtocol else { return }
+            do {
+                didReplaceMolecule =  try parentMolecule.replaceChildMolecule(with: replacementMolecule)
+            } catch {
+                possibleError = error
+            }
+            stop = didReplaceMolecule || possibleError != nil
+        }
+        if let error = possibleError {
+            throw error
+        }
+        return didReplaceMolecule
+    }
 }

MVMCoreUI/Atomic/Protocols/MoleculeDelegateProtocol.swift

@@ -9,6 +9,8 @@
 
 public protocol MoleculeDelegateProtocol: AnyObject {
     
+    func getTemplateModel() -> TemplateModelProtocol?
+    
     func getRootMolecules() -> [MoleculeModelProtocol]
     
     /// returns a module for the corresponding module name.
@@ -22,6 +24,10 @@ public protocol MoleculeDelegateProtocol: AnyObject {
 
 extension MoleculeDelegateProtocol {
     
+    public func getRootMolecules() -> [MoleculeModelProtocol] {
+        getTemplateModel()?.rootMolecules ?? []
+    }
+    
     public func moleculeLayoutUpdated(_ molecule: MoleculeViewProtocol) { }
 
     public func getModuleWithName(_ moleculeName: String) -> MoleculeModelProtocol? {
@@ -42,6 +48,11 @@ extension MoleculeDelegateProtocol {
 }
 
 extension MoleculeDelegateProtocol where Self: TemplateProtocol {
+    
+    public func getTemplateModel() -> TemplateModelProtocol? {
+        return templateModel
+    }
+    
     public func getRootMolecules() -> [MoleculeModelProtocol] {
         templateModel?.rootMolecules ?? []
     }

MVMCoreUI/Atomic/Protocols/MoleculeTreeTraversalProtocol.swift

@@ -38,7 +38,7 @@ public extension MoleculeTreeTraversalProtocol {
     
     func printMolecules(options: TreeTraversalOptions = .parentFirst) {
         depthFirstTraverse(options: options, depth: 1) { depth, molecule, stop in
-            print("\(String(repeating: ">>", count: depth)) \"\(molecule.moleculeName)\" [\(molecule)]")
+            print("\(String(repeating: ">>", count: depth)) \"\(molecule.moleculeName)\" [\(molecule): \(molecule.id)]")
         }
     }
     
@@ -50,14 +50,4 @@ public extension MoleculeTreeTraversalProtocol {
             return accumulator
         }
     }
-    
-    func replaceMolecule(with replacementMolecule: MoleculeModelProtocol) -> Bool {
-        var didReplaceMolecule = false
-        depthFirstTraverse(options: .parentFirst, depth: 0) { depth, molecule, stop in
-            guard let parentMolecule = molecule as? ParentMoleculeModelProtocol else { return }
-            didReplaceMolecule = parentMolecule.replaceChildMolecule(with: replacementMolecule)
-            stop = didReplaceMolecule
-        }
-        return didReplaceMolecule
-    }
 }

MVMCoreUI/Atomic/Templates/BaseTemplateModel.swift

@@ -32,7 +32,11 @@ import Foundation
     public var tabBarIndex: Int?
     
     public var shouldMaskScreenWhileRecording: Bool?
-
+    
+    public func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool {
+        return try replaceChildMolecule(at: &navigationBar, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Initializer
     //--------------------------------------------------

MVMCoreUI/Atomic/Templates/CollectionTemplateModel.swift

@@ -22,6 +22,11 @@
         }
         return super.rootMolecules
     }
+    
+    public override func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool {
+        return try super.replaceChildMolecule(with: molecule)
+        || (molecules != nil && replaceChildMolecule(in: &(molecules!), with: molecule))
+    }
 
     //--------------------------------------------------
     // MARK: - Initializer

MVMCoreUI/Atomic/Templates/ListPageTemplateModel.swift

@@ -26,6 +26,12 @@
         return super.rootMolecules
     }
     
+    public override func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool {
+        return try super.replaceChildMolecule(with: molecule)
+        || (molecules != nil && replaceChildMolecule(in: &(molecules!), with: molecule))
+        || replaceChildMolecule(at: &line, with: molecule)
+    }
+    
     /// This template requires content.
     func validateModelHasContent() throws {
         if header == nil,

MVMCoreUI/Atomic/Templates/StackPageTemplateModel.swift

@@ -16,7 +16,13 @@
     public var moleculeStack: StackModel
     
     public override var rootMolecules: [MoleculeModelProtocol] {
-        [navigationBar, header, moleculeStack, footer].compactMap { $0 }
+        super.rootMolecules + [moleculeStack]
+    }
+    
+    public override func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool {
+        return try super.replaceChildMolecule(with: molecule)
+        || replaceChildMolecule(at: &navigationBar, with: molecule)
+        || replaceChildMolecule(at: &moleculeStack, with: molecule)
     }
     
     //--------------------------------------------------

MVMCoreUI/Atomic/Templates/ThreeLayerModelBase.swift

@@ -21,6 +21,12 @@
         [navigationBar, header, footer].compactMap { $0 }
     }
     
+    public override func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool {
+        return try super.replaceChildMolecule(with: molecule)
+        || replaceChildMolecule(at: &header, with: molecule)
+        || replaceChildMolecule(at: &footer, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Init
     //--------------------------------------------------

MVMCoreUI/Atomic/Templates/ThreeLayerPageTemplateModel.swift

@@ -22,6 +22,11 @@
         return super.rootMolecules
     }
     
+    public override func replaceChildMolecule(with molecule: MoleculeModelProtocol) throws -> Bool {
+        return try super.replaceChildMolecule(with: molecule)
+        || replaceChildMolecule(at: &middle, with: molecule)
+    }
+    
     //--------------------------------------------------
     // MARK: - Init
     //--------------------------------------------------

MVMCoreUI/BaseControllers/ViewController.swift

@@ -513,9 +513,9 @@ import MVMCore
     // MARK: - MoleculeDelegateProtocol
     //--------------------------------------------------
     
-    open func getRootMolecules() -> [MoleculeModelProtocol] {
-        model?.rootMolecules ?? []
-    }
+    open func getTemplateModel() -> TemplateModelProtocol? { model }
+    
+    open func getRootMolecules() -> [MoleculeModelProtocol] { model?.rootMolecules ?? [] }
     
     // Needed otherwise when subclassed, the extension gets called.
     open func moleculeLayoutUpdated(_ molecule: MoleculeViewProtocol) { }

MVMCoreUI/Behaviors/ReplacementMoleculeBehavior.swift

@@ -9,27 +9,35 @@
 import Foundation
 import MVMCore
 
-public class ReplacableMoleculeBehaviorModel: PageBehaviorModelProtocol {
+public class ReplaceableMoleculeBehaviorModel: PageBehaviorModelProtocol {
     public class var identifier: String { "replaceMoleculeBehavior" }
     public var shouldAllowMultipleInstances: Bool { true }
     public var moleculeIds: [String]
 }
 
-public class ReplacableMoleculeBehavior: PageMoleculeTransformationBehavior {
+public class ReplaceableMoleculeBehavior: PageMoleculeTransformationBehavior {
     var moleculeIds: [String]
     
     public required init(model: PageBehaviorModelProtocol, delegateObject: MVMCoreUIDelegateObject?) {
-        moleculeIds = (model as! ReplacableMoleculeBehaviorModel).moleculeIds
+        moleculeIds = (model as! ReplaceableMoleculeBehaviorModel).moleculeIds
     }
     
     public func onPageNew(rootMolecules: [MoleculeModelProtocol], _ delegateObject: MVMCoreUIDelegateObject?) {
-        var shouldRefreshUI = false
+        
+        guard let templateModel = delegateObject?.moleculeDelegate?.getTemplateModel() else { return }
+        
+        templateModel.printMolecules()
+        
         for moleculeId in moleculeIds {
             guard let replacementModel = delegateObject?.moleculeDelegate?.getModuleWithName(moleculeId) else { continue }
-            let didReplace = rootMolecules.contains(where: { model in
-                return model.replaceMolecule(with: replacementModel)
-            })
-            shouldRefreshUI = shouldRefreshUI || didReplace
+            do {
+                let didReplace = try templateModel.replaceMolecule(with: replacementModel)
+                if !didReplace {
+                    MVMCoreLoggingHandler.addError(toLog: MVMCoreErrorObject(title: nil, messageToLog: "Failed to find '\(moleculeId)' in the current screen.", code: ErrorCode.viewControllerProcessingJSON.rawValue, domain: ErrorDomainSystem, location: String(describing: type(of: self)))!)
+                }
+            } catch {
+                MVMCoreLoggingHandler.addError(toLog: MVMCoreErrorObject.createErrorObject(for: error, location: String(describing: type(of: self)))!)
+            }
         }
     }
     

MVMCoreUI/OtherHandlers/CoreUIModelMapping.swift

@@ -227,7 +227,7 @@ open class CoreUIModelMapping: ModelMapping {
         ModelRegistry.register(handler: PageGetContactBehavior.self, for: PageGetContactBehaviorModel.self)
         ModelRegistry.register(handler: AddRemoveMoleculesBehavior.self, for: AddRemoveMoleculesBehaviorModel.self)
         ModelRegistry.register(handler: GetNotificationAuthStatusBehavior.self, for: GetNotificationAuthStatusBehaviorModel.self)
-        ModelRegistry.register(handler: ReplacableMoleculeBehavior.self, for: ReplacableMoleculeBehaviorModel.self)
+        ModelRegistry.register(handler: ReplaceableMoleculeBehavior.self, for: ReplaceableMoleculeBehaviorModel.self)
     }
 
     open override class func registerActions() {