Implement ability to add SI units

src/blenderbim/blenderbim/bim/module/unit/__init__.py

@@ -8,6 +8,7 @@ classes = (
     operator.DisableUnitEditingUI,
     operator.RemoveUnit,
     operator.AddMonetaryUnit,
+    operator.AddSIUnit,
     operator.EnableEditingUnit,
     operator.DisableEditingUnit,
     operator.EditUnit,

src/blenderbim/blenderbim/bim/module/unit/operator.py

@@ -1,5 +1,6 @@
 import bpy
 import ifcopenshell.api
+import ifcopenshell.util.unit
 import blenderbim.bim.helper
 from blenderbim.bim.ifc import IfcStore
 from ifcopenshell.api.unit.data import Data
@@ -156,8 +157,29 @@ class AddMonetaryUnit(bpy.types.Operator):
     def _execute(self, context):
         props = context.scene.BIMUnitProperties
         self.file = IfcStore.get_file()
-        unit = ifcopenshell.api.run("unit.add_monetary_unit", self.file)
-        ifcopenshell.api.run("unit.assign_unit", self.file, units=[unit])
+        ifcopenshell.api.run("unit.add_monetary_unit", self.file)
+        Data.load(self.file)
+        bpy.ops.bim.load_units()
+        return {"FINISHED"}
+
+
+class AddSIUnit(bpy.types.Operator):
+    bl_idname = "bim.add_si_unit"
+    bl_label = "Add SI Unit"
+    bl_options = {"REGISTER", "UNDO"}
+
+    def execute(self, context):
+        return IfcStore.execute_ifc_operator(self, context)
+
+    def _execute(self, context):
+        props = context.scene.BIMUnitProperties
+        self.file = IfcStore.get_file()
+        unit = ifcopenshell.api.run(
+            "unit.add_si_unit",
+            self.file,
+            unit_type=props.named_unit_types,
+            name=ifcopenshell.util.unit.si_type_names[props.named_unit_types],
+        )
         Data.load(self.file)
         bpy.ops.bim.load_units()
         return {"FINISHED"}

src/blenderbim/blenderbim/bim/module/unit/prop.py

@@ -1,6 +1,7 @@
 import bpy
 import ifcopenshell
 import ifcopenshell.util.schema
+import ifcopenshell.util.attribute
 from blenderbim.bim.ifc import IfcStore
 from blenderbim.bim.prop import StrProperty, Attribute
 from bpy.types import PropertyGroup
@@ -17,11 +18,14 @@ from bpy.props import (
 
 
 unitclasses_enum = []
+namedunittypes_enum = []
 
 
 def purge():
     global unitclasses_enum
+    global namedunittypes_enum
     unitclasses_enum = []
+    namedunittypes_enum = []
 
 
 def getUnitClasses(self, context):
@@ -33,6 +37,16 @@ def getUnitClasses(self, context):
     return unitclasses_enum
 
 
+def getNamedUnitTypes(self, context):
+    global namedunittypes_enum
+    if not len(namedunittypes_enum) and IfcStore.get_file():
+        values = ifcopenshell.util.attribute.get_enum_items(
+            IfcStore.get_schema().declaration_by_name("IfcNamedUnit").all_attributes()[1]
+        )
+        namedunittypes_enum.extend([(c, c, "") for c in sorted(values)])
+    return namedunittypes_enum
+
+
 class Unit(PropertyGroup):
     name: StringProperty(name="Name")
     unit_type: StringProperty(name="Unit Type")
@@ -47,4 +61,5 @@ class BIMUnitProperties(PropertyGroup):
     active_unit_index: IntProperty(name="Active Unit Index")
     active_unit_id: IntProperty(name="Active Unit Id")
     unit_classes: EnumProperty(items=getUnitClasses, name="Unit Classes")
+    named_unit_types: EnumProperty(items=getNamedUnitTypes, name="Named Unit Types")
     unit_attributes: CollectionProperty(name="Unit Attributes", type=Attribute)

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

@@ -40,8 +40,11 @@ class BIM_PT_units(Panel):
             row.operator("bim.add_monetary_unit", text="", icon="ADD")
         elif self.props.unit_classes == "IfcDerivedUnit":
             pass  # TODO
+        elif self.props.unit_classes == "IfcSIUnit":
+            row.prop(self.props, "named_unit_types", text="")
+            row.operator("bim.add_si_unit", text="", icon="ADD")
         else:
-            pass  # TODO
+            row.prop(self.props, "named_unit_types", text="")
 
         self.layout.template_list(
             "BIM_UL_units",