New feature to manipulate cost item quantities

src/ifcopenshell-python/ifcopenshell/api/cost/add_cost_item_quantity.py

@@ -0,0 +1,18 @@
+import ifcopenshell.api
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {"cost_item": None, "ifc_class": "IfcQuantityCount"}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        quantity = self.file.create_entity(self.settings["ifc_class"], Name="Unnamed")
+        quantity[3] = 0.0
+        cost_item = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcCostItem")
+        quantities = list(self.settings["cost_item"].CostQuantities or [])
+        quantities.append(quantity)
+        self.settings["cost_item"].CostQuantities = quantities
+        return quantity

src/ifcopenshell-python/ifcopenshell/api/cost/data.py

@@ -5,17 +5,20 @@ class Data:
     is_loaded = False
     cost_schedules = {}
     cost_items = {}
+    physical_quantities = {}
 
     @classmethod
     def purge(cls):
         cls.is_loaded = False
         cls.cost_schedules = {}
         cls.cost_items = {}
+        cls.physical_quantities = {}
 
     @classmethod
     def load(cls, file):
         cls.cost_schedules = {}
         cls.cost_items = {}
+        cls.physical_quantities = {}
 
         for cost_schedule in file.by_type("IfcCostSchedule"):
             data = cost_schedule.get_info()
@@ -36,7 +39,6 @@ class Data:
             data = cost_item.get_info()
             del data["OwnerHistory"]
             del data["CostValues"]
-            del data["CostQuantities"]
             data["RelatedObjects"] = []
             data["Controls"] = []
             for rel in cost_item.IsNestedBy:
@@ -44,4 +46,16 @@ class Data:
             for rel in cost_item.Controls:
                 [data["Controls"].append(o.id()) for o in rel.RelatedObjects or []]
             cls.cost_items[cost_item.id()] = data
+            cls.load_cost_item_quantities(cost_item, data)
         cls.is_loaded=True
+
+    @classmethod
+    def load_cost_item_quantities(cls, cost_item, data):
+        data["CostQuantities"] = []
+        data["TotalCostQuantities"] = 0.0
+        for quantity in cost_item.CostQuantities or []:
+            quantity_data = quantity.get_info()
+            del quantity_data["Unit"]
+            cls.physical_quantities[quantity.id()] = quantity_data
+            data["CostQuantities"].append(quantity.id())
+            data["TotalCostQuantities"] += quantity[3]

src/ifcopenshell-python/ifcopenshell/api/cost/edit_cost_item_quantity.py

@@ -0,0 +1,10 @@
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {"physical_quantity": None, "attributes": {}}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        for name, value in self.settings["attributes"].items():
+            setattr(self.settings["physical_quantity"], name, value)

src/ifcopenshell-python/ifcopenshell/api/cost/remove_cost_item_quantity.py

@@ -0,0 +1,14 @@
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {"cost_item": None, "physical_quantity": None}
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        if len(self.file.get_inverse(self.settings["physical_quantity"])) == 1:
+            self.file.remove(self.settings["physical_quantity"])
+            return
+        quantities = list(self.settings["cost_item"].CostQuantities or [])
+        quantities.remove(self.settings["physical_quantity"])
+        self.settings["cost_item"].CostQuantities = quantities