You can now assign/unassign products to groups. Part of #1153 roadmap.

src/ifcblenderexport/blenderbim/bim/module/group/__init__.py

@@ -7,6 +7,8 @@ classes = (
     operator.AddGroup,
     operator.EditGroup,
     operator.RemoveGroup,
+    operator.AssignGroup,
+    operator.UnassignGroup,
     operator.EnableEditingGroup,
     operator.DisableEditingGroup,
     prop.Group,

src/ifcblenderexport/blenderbim/bim/module/group/assign_group.py

@@ -0,0 +1,28 @@
+import ifcopenshell
+from blenderbim.bim.module.owner.api import create_owner_history
+from blenderbim.bim.module.owner.api import update_owner_history
+
+
+class Usecase:
+    def __init__(self, file, settings=None):
+        self.file = file
+        self.settings = {
+            "product": None,
+            "group": None,
+        }
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        if not self.settings["group"].IsGroupedBy:
+            return self.file.create_entity("IfcRelAssignsToGroup", **{
+                "GlobalId": ifcopenshell.guid.new(),
+                "OwnerHistory": create_owner_history(),
+                "RelatedObjects": [self.settings["product"]],
+                "RelatingGroup": self.settings["group"]
+            })
+        rel = self.settings["group"].IsGroupedBy[0]
+        related_objects = set(rel.RelatedObjects) or set()
+        related_objects.add(self.settings["product"])
+        rel.RelatedObjects = list(related_objects)
+        update_owner_history(rel)

src/ifcblenderexport/blenderbim/bim/module/group/data.py

@@ -3,17 +3,24 @@ from blenderbim.bim.ifc import IfcStore
 
 class Data:
     is_loaded = False
+    products = {}
     groups = {}
 
     @classmethod
     def purge(cls):
         cls.is_loaded = False
+        cls.products = {}
         cls.groups = {}
 
     @classmethod
     def load(cls):
+        cls.products = {}
         cls.groups = {}
         for group in IfcStore.get_file().by_type("IfcGroup", include_subtypes=False):
+            if group.IsGroupedBy:
+                for rel in group.IsGroupedBy:
+                    for product in rel.RelatedObjects:
+                        cls.products.setdefault(product.id(), []).append(group.id())
             data = group.get_info()
             del data["OwnerHistory"]
             cls.groups[group.id()] = data

src/ifcblenderexport/blenderbim/bim/module/group/operator.py

@@ -2,6 +2,8 @@ import bpy
 import blenderbim.bim.module.group.add_group as add_group
 import blenderbim.bim.module.group.edit_group as edit_group
 import blenderbim.bim.module.group.remove_group as remove_group
+import blenderbim.bim.module.group.assign_group as assign_group
+import blenderbim.bim.module.group.unassign_group as unassign_group
 from blenderbim.bim.ifc import IfcStore
 from blenderbim.bim.module.group.data import Data
 
@@ -111,3 +113,37 @@ class DisableEditingGroup(bpy.types.Operator):
     def execute(self, context):
         context.scene.BIMGroupProperties.active_group_id = 0
         return {"FINISHED"}
+
+
+class AssignGroup(bpy.types.Operator):
+    bl_idname = "bim.assign_group"
+    bl_label = "Assign Group"
+    product: bpy.props.StringProperty()
+    group: bpy.props.IntProperty()
+
+    def execute(self, context):
+        product = bpy.data.objects.get(self.product) if self.product else context.active_object
+        self.file = IfcStore.get_file()
+        assign_group.Usecase(self.file, {
+            "product": self.file.by_id(product.BIMObjectProperties.ifc_definition_id),
+            "group": self.file.by_id(self.group)
+        }).execute()
+        Data.load()
+        return {"FINISHED"}
+
+
+class UnassignGroup(bpy.types.Operator):
+    bl_idname = "bim.unassign_group"
+    bl_label = "Unassign Group"
+    product: bpy.props.StringProperty()
+    group: bpy.props.IntProperty()
+
+    def execute(self, context):
+        product = bpy.data.objects.get(self.product) if self.product else context.active_object
+        self.file = IfcStore.get_file()
+        unassign_group.Usecase(self.file, {
+            "product": self.file.by_id(product.BIMObjectProperties.ifc_definition_id),
+            "group": self.file.by_id(self.group)
+        }).execute()
+        Data.load()
+        return {"FINISHED"}

src/ifcblenderexport/blenderbim/bim/module/group/ui.py

@@ -56,17 +56,17 @@ class BIM_UL_groups(UIList):
             row = layout.row(align=True)
             row.label(text=item.name)
 
-            #if context.active_object and isinstance(context.active_object.data, Mesh):
+            if context.active_object:
-            #    mprops = context.active_object.data.BIMMeshProperties
+                oprops = context.active_object.BIMObjectProperties
-            #    if (
+                if (
-            #        mprops.ifc_definition_id in Data.items
+                    oprops.ifc_definition_id in Data.products
-            #        and item.ifc_definition_id in Data.items[mprops.ifc_definition_id]
+                    and item.ifc_definition_id in Data.products[oprops.ifc_definition_id]
-            #    ):
+                ):
-            #        op = row.operator("bim.unassign_presentation_layer", text="", icon="KEYFRAME_HLT", emboss=False)
+                    op = row.operator("bim.unassign_group", text="", icon="KEYFRAME_HLT", emboss=False)
-            #        op.layer = item.ifc_definition_id
+                    op.group = item.ifc_definition_id
-            #    else:
+                else:
-            #        op = row.operator("bim.assign_presentation_layer", text="", icon="KEYFRAME", emboss=False)
+                    op = row.operator("bim.assign_group", text="", icon="KEYFRAME", emboss=False)
-            #        op.layer = item.ifc_definition_id
+                    op.group = item.ifc_definition_id
 
             if context.scene.BIMGroupProperties.active_group_id == item.ifc_definition_id:
                 row.operator("bim.edit_group", text="", icon="CHECKMARK")

src/ifcblenderexport/blenderbim/bim/module/group/unassign_group.py

@@ -0,0 +1,25 @@
+import ifcopenshell
+from blenderbim.bim.module.owner.api import update_owner_history
+
+
+class Usecase:
+    def __init__(self, file, settings=None):
+        self.file = file
+        self.settings = {
+            "product": None,
+            "group": None,
+        }
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        if not self.settings["group"].IsGroupedBy:
+            return
+        rel = self.settings["group"].IsGroupedBy[0]
+        related_objects = set(rel.RelatedObjects) or set()
+        related_objects.remove(self.settings["product"])
+        if len(related_objects):
+            rel.RelatedObjects = list(related_objects)
+            update_owner_history(rel)
+        else:
+            self.file.remove(rel)

src/ifcblenderexport/blenderbim/bim/module/layer/data.py

@@ -16,7 +16,7 @@ class Data:
         cls.layers = {}
 
     @classmethod
-    def load(cls, item_id=None):
+    def load(cls):
         cls._file = IfcStore.get_file()
         if not cls._file:
             return