Python API: Add functions to ensure and clear IDProperties

This adds id_properties_clear() and id_properties_ensure() functions
to RNA structs. This is meant as an initial change based on discussion
in review of D9697. However, they may be useful in other situations.

The change requires refactoring the internal idproperties callback to
return a pointer to the IDProperty pointer, which actually turns out
to be quite a nice cleanup.

An id_properties attribute could be added in the future potentially.

Differential Revision: https://developer.blender.org/D11908

1 files changed, 2 insertions, 8 deletions

diff --git a/source/blender/makesrna/intern/rna_pose.c b/source/blender/makesrna/intern/rna_pose.c
index bb4939a010b..ee509fa92d4 100644
--- a/source/blender/makesrna/intern/rna_pose.c
+++ b/source/blender/makesrna/intern/rna_pose.c
@@ -224,16 +224,10 @@ static void rna_BoneGroup_name_set(PointerRNA *ptr, const char *value)
                  sizeof(agrp->name));
 }
 
-static IDProperty *rna_PoseBone_idprops(PointerRNA *ptr, bool create)
+static IDProperty **rna_PoseBone_idprops(PointerRNA *ptr)
 {
   bPoseChannel *pchan = ptr->data;
-
-  if (create && !pchan->prop) {
-    IDPropertyTemplate val = {0};
-    pchan->prop = IDP_New(IDP_GROUP, &val, "RNA_PoseBone group");
-  }
-
-  return pchan->prop;
+  return &pchan->prop;
 }
 
 static void rna_Pose_ik_solver_set(struct PointerRNA *ptr, int value)