pset.assign_pset, pset.unassign_pset

src/ifcopenshell-python/ifcopenshell/api/pset/__init__.py

@@ -26,9 +26,11 @@ For example, if a door has a fire rating, it is stored as a property.
 from .. import wrap_usecases
 from .add_pset import add_pset
 from .add_qto import add_qto
+from .assign_pset import assign_pset
 from .edit_pset import edit_pset
 from .edit_qto import edit_qto
 from .remove_pset import remove_pset
+from .unassign_pset import unassign_pset
 from .unshare_pset import unshare_pset
 
 wrap_usecases(__path__, __name__)
@@ -36,8 +38,10 @@ wrap_usecases(__path__, __name__)
 __all__ = [
     "add_pset",
     "add_qto",
+    "assign_pset",
     "edit_pset",
     "edit_qto",
     "remove_pset",
+    "unassign_pset",
     "unshare_pset",
 ]

src/ifcopenshell-python/ifcopenshell/api/pset/add_pset.py

@@ -18,6 +18,7 @@
 
 import ifcopenshell
 import ifcopenshell.api.owner
+import ifcopenshell.api.pset
 import ifcopenshell.guid
 from typing import Optional
 
@@ -107,16 +108,9 @@ def add_pset(
                 "Name": settings["name"],
             },
         )
-        file.create_entity(
-            "IfcRelDefinesByProperties",
-            **{
-                "GlobalId": ifcopenshell.guid.new(),
-                "OwnerHistory": ifcopenshell.api.owner.create_owner_history(file),
-                "RelatedObjects": [settings["product"]],
-                "RelatingPropertyDefinition": pset,
-            },
-        )
+        ifcopenshell.api.pset.assign_pset(file, [settings["product"]], pset)
         return pset
+
     elif settings["product"].is_a("IfcTypeObject"):
         for definition in settings["product"].HasPropertySets or []:
             if definition.Name == settings["name"]:
@@ -130,10 +124,9 @@ def add_pset(
                 "Name": settings["name"],
             },
         )
-        has_property_sets = list(settings["product"].HasPropertySets or [])
-        has_property_sets.append(pset)
-        settings["product"].HasPropertySets = has_property_sets
+        ifcopenshell.api.pset.assign_pset(file, [settings["product"]], pset)
         return pset
+
     # in IFC2X3 IfcMaterialDefinition not yet existed
     elif settings["product"].is_a("IfcMaterialDefinition") or settings["product"].is_a("IfcMaterial"):
         kwargs = {"Material": settings["product"]}

src/ifcopenshell-python/ifcopenshell/api/pset/assign_pset.py

@@ -0,0 +1,94 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell
+import ifcopenshell.api.owner
+import ifcopenshell.guid
+import ifcopenshell.util.element
+from typing import Union
+
+
+def assign_pset(
+    file: ifcopenshell.file,
+    products: list[ifcopenshell.entity_instance],
+    pset: ifcopenshell.entity_instance,
+) -> Union[ifcopenshell.entity_instance, None]:
+    """Assign property set to provided elements.
+
+    This method can be used to make psets shared by multiple elements.
+
+    :param products: Elements (or element types) to assign the pset to.
+    :param pset: Property set.
+    :return: None if `products` is empty or has only type elements.
+        IfcRelDefinesByProperties if `products` contains occurrences.
+
+    Example:
+
+    .. code:: python
+
+        element = ifcopenshell.api.root.create_entity(model, ifc_class="IfcWall")
+        ifcopenshell.api.pset.assign_pset(model, [element], pset)
+        # Pset is now assigned.
+        assert ifcopenshell.util.element.get_elements_using_pset(pset) == {element}
+
+        element1 = ifcopenshell.api.root.create_entity(model, ifc_class="IfcWall")
+        element2 = ifcopenshell.api.root.create_entity(model, ifc_class="IfcWall")
+        ifcopenshell.api.pset.assign_pset(model, [element1, element2], pset)
+        # Pset is now shared by multiple elements.
+        assert ifcopenshell.util.element.get_elements_using_pset(pset) == {element, element1, element2}
+
+        # Same for element types.
+        element_type = ifcopenshell.api.root.create_entity(model, ifc_class="IfcWallType")
+        ifcopenshell.api.pset.assign_pset(model, [element_type], type_pset)
+        # Pset is now assigned to the type.
+        assert ifcopenshell.util.element.get_elements_using_pset(type_pset) == {element_type}
+    """
+    is_ifc2x3 = file.schema == "IFC2X3"
+
+    products_occurrences: set[ifcopenshell.entity_instance] = set()
+    products_types: set[ifcopenshell.entity_instance] = set()
+    for product in products:
+        if product.is_a("IfcTypeProduct"):
+            products_types.add(product)
+        else:
+            products_occurrences.add(product)
+
+    rel = None
+    # Check occurrences using pset.
+    if products_occurrences:
+        rels = pset.PropertyDefinitionOf if is_ifc2x3 else pset.DefinesOccurrence
+        rel = next(iter(rels), None)
+        if rel is not None:
+            objs = set(rel.RelatedObjects) | products_occurrences
+            rel.RelatedObjects = list(objs)
+        else:
+            rel = file.create_entity(
+                "IfcRelDefinesByProperties",
+                **{
+                    "GlobalId": ifcopenshell.guid.new(),
+                    "OwnerHistory": ifcopenshell.api.owner.create_owner_history(file),
+                    "RelatedObjects": list(products_occurrences),
+                    "RelatingPropertyDefinition": pset,
+                },
+            )
+
+    for product in products_types:
+        psets = list(product.HasPropertySets or [])
+        product.HasPropertySets = psets + [pset]
+
+    return rel

src/ifcopenshell-python/ifcopenshell/api/pset/unassign_pset.py

@@ -0,0 +1,80 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# This file is part of IfcOpenShell.
+#
+# IfcOpenShell is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Lesser General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# IfcOpenShell is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with IfcOpenShell.  If not, see <http://www.gnu.org/licenses/>.
+
+import ifcopenshell
+import ifcopenshell.api.owner
+import ifcopenshell.guid
+import ifcopenshell.util.element
+
+
+def unassign_pset(
+    file: ifcopenshell.file,
+    products: list[ifcopenshell.entity_instance],
+    pset: ifcopenshell.entity_instance,
+) -> None:
+    """Unassign property set from the provided elements.
+
+    :param products: Elements (or element types) to assign the pset from.
+    :param pset: Property set.
+
+    Example:
+
+    .. code:: python
+
+        element1 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        element2 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        ifcopenshell.api.pset.assign_pset(self.file, [element1, element2], pset)
+
+        # Pset is now shared by 2 elements.
+        assert ifcopenshell.util.element.get_elements_using_pset(pset) == {element1, element2}
+
+        ifcopenshell.api.pset.unassign_pset(self.file, [element2], pset)
+        # Pset was unassigned from element2.
+        assert ifcopenshell.util.element.get_elements_using_pset(pset) == {element1}
+
+    """
+    is_ifc2x3 = file.schema == "IFC2X3"
+
+    products_occurrences: set[ifcopenshell.entity_instance] = set()
+    products_types: set[ifcopenshell.entity_instance] = set()
+    for product in products:
+        if product.is_a("IfcTypeProduct"):
+            products_types.add(product)
+        else:
+            products_occurrences.add(product)
+
+    # Check occurrences using pset.
+    if products_occurrences:
+        rels = pset.PropertyDefinitionOf if is_ifc2x3 else pset.DefinesOccurrence
+        for rel in rels:
+            objs = set(rel.RelatedObjects)
+            if not any(p in objs for p in products_occurrences):
+                continue
+            objs.difference_update(products_occurrences)
+            if objs:
+                rel.RelatedObjects = list(objs)
+            else:
+                history = rel.OwnerHistory
+                file.remove(rel)
+                if history:
+                    ifcopenshell.util.element.remove_deep2(file, history)
+
+    for product in products_types:
+        psets = list(product.HasPropertySets)
+        psets.remove(pset)
+        product.HasPropertySets = psets or None

src/ifcopenshell-python/ifcopenshell/api/pset/unshare_pset.py

@@ -18,6 +18,7 @@
 
 import ifcopenshell
 import ifcopenshell.api.owner
+import ifcopenshell.api.pset
 import ifcopenshell.guid
 import ifcopenshell.util.element
 
@@ -34,8 +35,28 @@ def unshare_pset(
     :param products: Elements (or element types) to link the pset to.
     :param pset: Shared property set.
     :return: List of copied property sets.
+
+    Example:
+
+    .. code:: python
+
+        element1 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        element2 = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        ifcopenshell.api.pset.assign_pset(self.file, [element1, element2], pset)
+
+        # Pset is now shared by 2 elements.
+        assert ifcopenshell.util.element.get_elements_using_pset(pset) == {element1, element2}
+
+        new_psets = ifcopenshell.api.pset.unshare_pset(self.file, [element2], pset)
+
+        # element2 was unassigned from the original pset.
+        assert ifcopenshell.util.element.get_elements_using_pset(pset) == {element1}
+        new_pset = new_psets[0]
+
+        # New pset was created and was assigned to element2.
+        assert new_pset != pset
+        assert ifcopenshell.util.element.get_elements_using_pset(new_pset) == {element2}
     """
-    is_ifc2x3 = file.schema == "IFC2X3"
     products_occurrences: set[ifcopenshell.entity_instance] = set()
     products_types: set[ifcopenshell.entity_instance] = set()
     for product in products:
@@ -44,51 +65,12 @@ def unshare_pset(
         else:
             products_occurrences.add(product)
 
-    # Check occurrences using pset.
-    rels = pset.PropertyDefinitionOf if is_ifc2x3 else pset.DefinesOccurrence
-    for rel in rels:
-        objs = set(rel.RelatedObjects)
-        if not any(p in objs for p in products_occurrences):
-            continue
-        objs.difference_update(products_occurrences)
-        if objs:
-            rel.RelatedObjects = list(objs)
-        else:
-            history = rel.OwnerHistory
-            file.remove(rel)
-            if history:
-                ifcopenshell.util.element.remove_deep2(file, history)
-
-    # Check types using pset.
-    for product in products_types:
-        if not (psets := product.HasPropertySets):
-            continue
-        psets: list[ifcopenshell.entity_instance] = list(psets)
-        psets.remove(pset)
-        product.HasPropertySets = psets
-
-    def assign_pset(product: ifcopenshell.entity_instance, pset: ifcopenshell.entity_instance) -> None:
-        if product.is_a("IfcTypeProduct"):
-            psets = list(product.HasPropertySets or [])
-            if not psets:
-                psets = []
-            product.HasPropertySets = psets + [pset]
-            return
-
-        file.create_entity(
-            "IfcRelDefinesByProperties",
-            **{
-                "GlobalId": ifcopenshell.guid.new(),
-                "OwnerHistory": ifcopenshell.api.owner.create_owner_history(file),
-                "RelatedObjects": [product],
-                "RelatingPropertyDefinition": pset_copy,
-            },
-        )
+    ifcopenshell.api.pset.unassign_pset(file, products, pset)
 
     pset_copies: list[ifcopenshell.entity_instance] = []
     for product in products:
         pset_copy = ifcopenshell.util.element.copy_deep(file, pset)
         pset_copies.append(pset_copy)
-        assign_pset(product, pset_copy)
+        ifcopenshell.api.pset.assign_pset(file, [product], pset_copy)
 
     return pset_copies

src/ifcopenshell-python/ifcopenshell/api/root/reassign_class.py

@@ -19,6 +19,7 @@
 import ifcopenshell
 import ifcopenshell.api.aggregate
 import ifcopenshell.api.geometry
+import ifcopenshell.api.pset
 import ifcopenshell.api.spatial
 import ifcopenshell.api.type
 import ifcopenshell.guid
@@ -126,18 +127,12 @@ class Usecase:
 
         if switch_type == "type_to_occurrence":
             occurrences = ifcopenshell.util.element.get_types(element)
+            # Don't need to reassign as psets are linked to type directly, without rel.
             psets_to_reassign = element.HasPropertySets or []
 
             element = self.reassign_class(element, ifc_class, predefined_type)
             ifcopenshell.api.type.unassign_type(self.file, occurrences)
 
-            for pset in psets_to_reassign:
-                rel = self.file.create_entity(
-                    "IfcRelDefinesByProperties",
-                    GlobalId=ifcopenshell.guid.new(),
-                    RelatedObjects=[element],
-                    RelatingPropertyDefinition=pset,
-                )
         else:  # occurrence_to_type
             element_type = ifcopenshell.util.element.get_type(element)
             # Handle element type.
@@ -150,28 +145,17 @@ class Usecase:
             elif ifcopenshell.util.element.get_aggregate(element):
                 ifcopenshell.api.aggregate.unassign_object(self.file, [element])
 
-            for rel in element.IsDefinedBy:
-                pset: ifcopenshell.entity_instance = rel.RelatingPropertyDefinition
-                objs = list(rel.RelatedObjects)
-                objs.remove(element)
-                if objs:
-                    rel.RelatedObjects = objs
-                else:
-                    history = getattr(rel, "OwnerHistory", None)
-                    self.file.remove(rel)
-                    if history:
-                        ifcopenshell.util.element.remove_deep2(self.file, history)
-                psets_to_reassign.append(pset)
-
             psets = ifcopenshell.util.element.get_psets(element)
             for pset_name in psets:
                 pset = self.file.by_id(psets[pset_name]["id"])
+                psets_to_reassign.append(pset)
+                ifcopenshell.api.pset.unassign_pset(self.file, [element], pset)
 
             element = self.reassign_class(element, ifc_class, predefined_type)
 
-            # Reassign psets.
-            if psets_to_reassign:
-                element.HasPropertySets = psets_to_reassign
+        # Reassign psets.
+        for pset in psets_to_reassign:
+            ifcopenshell.api.pset.assign_pset(self.file, [element], pset)
 
         # Reassign representations.
         for rep in representations: