Address comments

Signed-off-by: Nate Koenig <[email protected]>

include/ignition/gazebo/components/Recreate.hh

@@ -29,7 +29,15 @@ namespace gazebo
 inline namespace IGNITION_GAZEBO_VERSION_NAMESPACE {
 namespace components
 {
-  /// \brief A component that identifies an entity needs to be recreated
+  /// \brief A component that identifies an entity needs to be recreated.
+  /// Currently, only Models will be processed for recreation by the
+  /// SimulationRunner in the ProcessRecreateEntitiesRemove and
+  /// ProcessRecreateEntitiesCreate functions.
+  ///
+  /// The GUI ModelEditor contains example code on how to use this
+  /// component. For example, the ModelEditor allows a user to add a link to an
+  /// existing model. The existing model is tagged with this component so
+  /// that it can be recreated by the server.
   using Recreate = Component<NoData, class RecreateTag>;
   IGN_GAZEBO_REGISTER_COMPONENT("ign_gazebo_components.Recreate", Recreate)
 }

src/SimulationRunner.cc

@@ -1312,27 +1312,47 @@ void SimulationRunner::ProcessRecreateEntitiesCreate()
   IGN_PROFILE("SimulationRunner::ProcessRecreateEntitiesCreate");
 
   // clone the original entities
-  std::set<Entity> entitiesToRemoveRecreateComp;
   for (auto & ent : this->entitiesToRecreate)
   {
     auto nameComp = this->entityCompMgr.Component<components::Name>(ent);
     auto parentComp =
         this->entityCompMgr.Component<components::ParentEntity>(ent);
-    // set allowRenaming to false so the entities keep their original name
-    Entity clonedEntity = this->entityCompMgr.Clone(ent,
-       parentComp->Data(), nameComp->Data(), false);
-    entitiesToRemoveRecreateComp.insert(clonedEntity);
-    entitiesToRemoveRecreateComp.insert(ent);
-  }
+    if (nameComp  && parentComp)
+    {
+      // set allowRenaming to false so the entities keep their original name
+      Entity clonedEntity = this->entityCompMgr.Clone(ent,
+         parentComp->Data(), nameComp->Data(), false);
 
-  // remove the Recreate component so they do not get recreated again in the
-  // next iteration
-  for (auto &ent : entitiesToRemoveRecreateComp)
-  {
-    if (!this->entityCompMgr.RemoveComponent<components::Recreate>(ent))
+      // remove the Recreate component so they do not get recreated again in the
+      // next iteration
+      if (!this->entityCompMgr.RemoveComponent<components::Recreate>(ent))
+      {
+        ignerr << "Failed to remove Recreate component from entity["
+          << ent << "]" << std::endl;
+      }
+
+      if (!this->entityCompMgr.RemoveComponent<components::Recreate>(
+            clonedEntity))
+      {
+        ignerr << "Failed to remove Recreate component from entity["
+          << clonedEntity << "]" << std::endl;
+      }
+    }
+    else
     {
-      ignerr << "Failed to remove Recreate component from entity["
-        << ent << "]" << std::endl;
+      if (!nameComp)
+      {
+        ignerr << "Missing name component for entity[" << ent << "]. "
+          << "The entity will not be cloned during the recreation process."
+          << std::endl;
+      }
+
+      if (!parentComp)
+      {
+        ignerr << "Missing parent component for entity[" << ent << "]. "
+          << "The entity will not be cloned during the recreation process."
+          << std::endl;
+      }
     }
   }