From 2dee4d3ac92fef4268ae313ad06b283a68e548d2 Mon Sep 17 00:00:00 2001
From: sconel <sconel@amazon.com>
Date: Wed, 9 Jun 2021 17:37:41 -0700
Subject: [PATCH] Add support to export nested container entities. Resolves
 missing parents in spawnables

---
 .../AzToolsFramework/Prefab/Instance/Instance.cpp        | 5 +++--
 .../AzToolsFramework/Prefab/Instance/Instance.h          | 9 ++++++++-
 .../AzToolsFramework/Prefab/Spawnable/SpawnableUtils.cpp | 6 +-----
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.cpp b/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.cpp
index 766a293b4a..83a76aeb01 100644
--- a/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.cpp
+++ b/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.cpp
@@ -187,13 +187,14 @@ namespace AzToolsFramework
             return removedEntity;
         }
 
-        void Instance::DetachNestedEntities(const AZStd::function<void(AZStd::unique_ptr<AZ::Entity>)>& callback)
+        void Instance::DetachAllEntitiesInHierarchy(const AZStd::function<void(AZStd::unique_ptr<AZ::Entity>)>& callback)
         {
+            callback(AZStd::move(DetachContainerEntity()));
             DetachEntities(callback);
 
             for (const auto& [instanceAlias, instance] : m_nestedInstances)
             {
-                instance->DetachNestedEntities(callback);
+                instance->DetachAllEntitiesInHierarchy(callback);
             }
         }
 
diff --git a/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.h b/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.h
index d14203e2e5..bba20cbe8a 100644
--- a/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.h
+++ b/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Instance/Instance.h
@@ -87,7 +87,14 @@ namespace AzToolsFramework
             bool AddEntity(AZ::Entity& entity, EntityAlias entityAlias);
             AZStd::unique_ptr<AZ::Entity> DetachEntity(const AZ::EntityId& entityId);
             void DetachEntities(const AZStd::function<void(AZStd::unique_ptr<AZ::Entity>)>& callback);
-            void DetachNestedEntities(const AZStd::function<void(AZStd::unique_ptr<AZ::Entity>)>& callback);
+
+            /**
+            * Detaches all entities in the instance hierarchy, including; all direct and nested entities, all container entities.
+            * Note that without container entities the hierarchy that remains cannot be used further without restoring new ones
+            * @param callback A user provided callback that can be used to capture ownership and manipulate the detached entities.
+            */
+            void DetachAllEntitiesInHierarchy(const AZStd::function<void(AZStd::unique_ptr<AZ::Entity>)>& callback);
+
             void RemoveNestedEntities(const AZStd::function<bool(const AZStd::unique_ptr<AZ::Entity>&)>& filter);
 
             void Reset();
diff --git a/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Spawnable/SpawnableUtils.cpp b/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Spawnable/SpawnableUtils.cpp
index 3c91f99b05..241d2a3bd5 100644
--- a/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Spawnable/SpawnableUtils.cpp
+++ b/Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Spawnable/SpawnableUtils.cpp
@@ -38,11 +38,7 @@ namespace AzToolsFramework::Prefab::SpawnableUtils
                                                                               // going to be used to create clones of the entities.
         {
             AzFramework::Spawnable::EntityList& entities = spawnable.GetEntities();
-            if (instance.HasContainerEntity())
-            {
-                entities.emplace_back(AZStd::move(instance.DetachContainerEntity()));
-            }
-            instance.DetachNestedEntities(
+            instance.DetachAllEntitiesInHierarchy(
                 [&entities](AZStd::unique_ptr<AZ::Entity> entity)
                 {
                     entities.emplace_back(AZStd::move(entity));