New classification utility module

src/ifcopenshell-python/ifcopenshell/util/classification.py

@@ -0,0 +1,52 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2022 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.util.element
+
+
+def get_references(element, should_inherit=True):
+    results = set()
+    if should_inherit:
+        element_type = ifcopenshell.util.element.get_type(element)
+        if element_type and element_type != element:
+            results.update(get_references(element_type))
+    results.update(
+        {
+            r.RelatingClassification
+            for r in getattr(element, "HasAssociations", [])
+            if r.is_a("IfcRelAssociatesClassification")
+        }
+    )
+    return results
+
+
+def get_classification(reference):
+    if reference.is_a("IfcClassification"):
+        return reference
+    return get_classification(reference.ReferencedSource)
+
+
+def get_inherited_references(reference):
+    results = []
+    while True:
+        if not reference or reference.is_a("IfcClassification"):
+            break
+        results.append(reference)
+        reference = reference.ReferencedSource
+    return results
+