Fix #971. New utility function to query which psets/qtos apply to a class.

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

@@ -0,0 +1,39 @@
+import ifcopenshell
+
+property_set_template_files = []
+psets = {}
+qtos = {}
+applicable_psets = {}
+applicable_qtos = {}
+
+
+def load_property_set_template(path):
+    property_set_template_files.append(ifcopenshell.open(path))
+    for prop in property_set_template_files[-1].by_type("IfcPropertySetTemplate"):
+        if prop.Name[0:4] == "Qto_":
+            qtos[prop.Name] = {"HasPropertyTemplates": {p.Name: p for p in prop.HasPropertyTemplates}}
+            entity = prop.ApplicableEntity if prop.ApplicableEntity else "IfcRoot"
+            applicable_qtos.setdefault(entity, []).append(prop.Name)
+        else:
+            psets[prop.Name] = {"HasPropertyTemplates": {p.Name: p for p in prop.HasPropertyTemplates}}
+            entity = prop.ApplicableEntity if prop.ApplicableEntity else "IfcRoot"
+            applicable_psets.setdefault(entity, []).append(prop.Name)
+
+
+def get_applicable_psetqtos(schema_version, ifc_class, is_pset=False, is_qto=False):
+    def is_a(entity, ifc_class):
+        if entity.name() == ifc_class:
+            return True
+        return is_a(entity.supertype(), ifc_class) if entity.supertype() else False
+
+    results = []
+    schema = ifcopenshell.ifcopenshell_wrapper.schema_by_name(schema_version)
+    entity = schema.declaration_by_name(ifc_class)
+    if is_pset:
+        search_items = applicable_psets.items()
+    elif is_qto:
+        search_items = applicable_qtos.items()
+    for ifc_class, pset_names in search_items:
+        if is_a(entity, ifc_class):
+            results.extend(pset_names)
+    return results