store canonical link mappings in its own class, not in a component

Signed-off-by: Ashton Larkin <[email protected]>

Author: adlarkin

include/ignition/gazebo/components/ReferenceModels.hh

@@ -59,7 +59,6 @@
 #include "ignition/gazebo/components/ParentEntity.hh"
 #include "ignition/gazebo/components/Physics.hh"
 #include "ignition/gazebo/components/Pose.hh"
-#include "ignition/gazebo/components/ReferenceModels.hh"
 #include "ignition/gazebo/components/RgbdCamera.hh"
 #include "ignition/gazebo/components/Scene.hh"
 #include "ignition/gazebo/components/SelfCollide.hh"
@@ -404,11 +403,8 @@ Entity SdfEntityCreator::CreateEntities(const sdf::Model *_model,
         canonicalLinkPair.second, modelEntity, *this->dataPtr->ecm);
     if (kNullEntity != canonicalLinkEntity)
     {
-      // Map this canonical link to the model. Since a link may be the
-      // canonical link for multiple models (example: nested models), create
-      // a component that completes this mapping if it doesn't already exist.
-      this->dataPtr->ecm->ComponentDefault<components::ReferenceModels>(
-          canonicalLinkEntity)->Data().AddModel(modelEntity);
+      this->dataPtr->ecm->CreateComponent(
+          modelEntity, components::ModelCanonicalLink(canonicalLinkEntity));
     }
     else
     {