Spawnable validation (#613)

* Add validation of spawnable asset before spawn service response

Signed-off-by: Artur Kamieniecki <[email protected]>

Gems/ROS2/Code/Source/Spawner/ROS2SpawnerComponent.cpp

@@ -134,6 +134,32 @@ namespace ROS2
         }
 
         auto spawnable = m_controller.GetSpawnables().find(spawnableName);
+
+        if (spawnable->second->IsLoading())
+        {
+            // This is an Editor only situation. All assets during game mode are fully loaded.
+            response.success = false;
+            response.status_message = "Asset for spawnable " + request->name + " has not yet loaded.";
+            service_handle->send_response(*header, response);
+            return;
+        }
+
+        if (spawnable->second->IsError())
+        {
+            response.success = false;
+            response.status_message = "Spawnable " + request->name + " loaded with an error.";
+            service_handle->send_response(*header, response);
+            return;
+        }
+
+        if (!m_tickets.contains(spawnableName))
+        {
+            // if a ticket for this spawnable was not created but the spawnable name is correct, create the ticket and then use it to
+            // spawn an entity
+            auto spawnable = m_controller.GetSpawnables().find(spawnableName);
+            m_tickets.emplace(spawnable->first, AzFramework::EntitySpawnTicket(spawnable->second));
+        }
+
         auto spawnableTicket = AzFramework::EntitySpawnTicket(spawnable->second);
         auto ticketId = spawnableTicket.GetId();
         AZStd::string ticketName = spawnable->first + "_" + AZStd::to_string(ticketId);