Now it's possible to see the selected object related cost items and related quantities in qto n-panel

src/blenderbim/blenderbim/bim/module/qto/ui.py

@@ -16,10 +16,11 @@
 # You should have received a copy of the GNU General Public License
 # along with BlenderBIM Add-on.  If not, see <http://www.gnu.org/licenses/>.
 
-from bpy.types import Panel
+import bpy
+from blenderbim.bim.module.qto.data import QtoData
 
 
-class BIM_PT_qto_utilities(Panel):
+class BIM_PT_qto_utilities(bpy.types.Panel):
     bl_idname = "BIM_PT_qto_utilities"
     bl_label = "Quantity Take-off"
     bl_options = {"DEFAULT_CLOSED"}
@@ -28,6 +29,9 @@ class BIM_PT_qto_utilities(Panel):
     bl_category = "BlenderBIM"
 
     def draw(self, context):
+        if not QtoData.is_loaded:
+            QtoData.load()
+
         layout = self.layout
         props = context.scene.BIMQtoProperties
 
@@ -57,3 +61,28 @@ class BIM_PT_qto_utilities(Panel):
 
         row = layout.row(align=True)
         row.operator("bim.calculate_all_quantities", icon="MOD_EDGESPLIT")
+
+        if context.selected_objects:
+            row = layout.row(align=True)
+            row.label(text=f"Relating Cost Item:")
+
+            if QtoData.data['has_cost_item']:
+                for relating_cost_item in QtoData.data['relating_cost_items']:
+                    row.label(text=f"\n")
+                    row = layout.row(align=True)
+                    row.label(text=f"Cost item name:")
+                    row.label(text=f"{relating_cost_item['cost_item_name']}")
+                    row = layout.row(align=True)
+                    row.label(text=f"Quantity name:")
+                    row.label(text=f"{relating_cost_item['quantity_name']}")
+                    row = layout.row(align=True)
+                    row.label(text=f"Quantity value:")
+                    row.label(text=f"{relating_cost_item['quantity_value']}")
+                    row = layout.row(align=True)
+                    row.label(text=f"Quantity type:")
+                    row.label(text=f"{relating_cost_item['quantity_type']}")
+                    row = layout.row(align=True)
+            else:
+                row = layout.row(align=True)
+                row.label(text = f"No cost item related")
+

src/blenderbim/blenderbim/core/tool.py

@@ -518,6 +518,7 @@ class Qto:
     def add_product_base_qto(cls, product): pass
     def get_new_calculated_quantity(cls, qto_name, quantity_name, object): pass
     def get_new_guessed_quantity(cls, object, qto_name, quantity_name, ): pass
+    def get_related_cost_item_quantities(cls, product): pass
 
 
 @interface

src/blenderbim/blenderbim/tool/qto.py

@@ -127,3 +127,54 @@ class Qto(blenderbim.core.tool.Qto):
             ):
                 continue
             return rel.RelatingPropertyDefinition
+
+    @classmethod
+    def get_related_cost_item_quantities(cls, product):
+        """_summary_: Returns the related cost item and related quantities of the product
+
+        :param ifc-instance product: ifc instance
+        :type product: ifcopenshell.entity_instance.entity_instance
+
+        :return list of dictionaries in the form [
+        {
+        "cost_item_id" : XX,
+        "cost_item_name" : XX,
+        "quantity_id" : XX,
+        "quantity_name" : XX,
+        "quantity_value" : XX,
+        "quantity_type" : XX
+        }]
+        :rtype list
+
+        Example:
+
+        .. code::Python
+        import blenderbim.tool as tool
+
+        relating_cost_items = tool.Qto.relating_cost_items(my_beautiful_wall)
+        for relating_cost_item in relating_cost_items:
+            print(f"RELATING COST ITEM NAME: {relating_cost_item["cost_item_name"]}")
+            print(f"RELATING COST QUANTITY NAME: {relating_cost_item["quantity_name"]}")
+            ...
+        """
+        quantities = cls.get_base_qto(product).Quantities
+        model = tool.Ifc.get()
+        cost_items = model.by_type("IfcCostItem")
+        result = []
+
+        for cost_item in cost_items:
+            cost_item_quantities = cost_item.CostQuantities if cost_item.CostQuantities is not None else []
+            for cost_item_quantity in cost_item_quantities:
+                for quantity in quantities:
+                    if quantity == cost_item_quantity:
+                        result.append(
+                            {
+                                "cost_item_id" : cost_item.id(),
+                                "cost_item_name" : cost_item.Name,
+                                "quantity_id" : quantity.id(),
+                                "quantity_name" : quantity.Name,
+                                "quantity_value" : quantity[3],
+                                "quantity_type" : quantity.is_a(),
+                            }
+                        )
+        return result

src/blenderbim/test/tool/test_qto.py

@@ -142,3 +142,19 @@ class TestGetBaseQto(test.bim.bootstrap.NewFile):
         product = tool.Ifc.get_entity(wall_obj)
         assert not subject.get_base_qto(product) == True
 
+class TestGetRelatedCostItemQuantities(test.bim.bootstrap.NewFile):
+    def test_run(self):
+        ifc = ifcopenshell.file()
+        tool.Ifc.set(ifc)
+        wall = ifc.createIfcWall()
+        product = tool.Ifc.get_entity(wall)
+        schedule = ifcopenshell.api.run("cost.add_cost_schedule", ifc)
+        item = ifcopenshell.api.run("cost.add_cost_item", ifc, cost_schedule=schedule)
+        ifcopenshell.api.run("cost.edit_cost_item", ifc, cost_item=item, attributes={"Name": "Foo"})
+        qto = ifcopenshell.api.run("pset.add_qto", ifc, product=wall, name="Qto_WallBaseQuantities")
+        ifcopenshell.api.run("pset.edit_qto", ifc, qto=qto, properties={"NetVolume": 42.0})
+        ifcopenshell.api.run("cost.assign_cost_item_quantity", ifc, cost_item=item, products=[wall], prop_name="NetVolume")
+        assert subject.get_related_cost_item_quantities(wall)[0]['cost_item_name'] == "Foo"
+        assert subject.get_related_cost_item_quantities(wall)[0]['quantity_name'] == "NetVolume"
+        assert subject.get_related_cost_item_quantities(wall)[0]['quantity_value'] == 42
+        assert subject.get_related_cost_item_quantities(wall)[0]['quantity_type'] == "IfcQuantityVolume"