Copy deep can now exclude things, useful for copying representation graphs where you don't want to duplicate the context

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

@@ -190,13 +190,17 @@ def get_elements_by_material(ifc_file, material):
     """
     Retrieves the elements related to a material.
 
+    This includes elements using the material as part of a material set or set
+    usage.
+
     :param ifc_file: The IFC file
     :param material: The IFC Material entity
-    :return: The elements related to the material
+    :return: A list of elements using the to the material
 
     Example::
-    material = file.by_type("IfcMaterial")[0]
+
-    elements = ifcopenshell.util.element.get_elements_by_material(file, material)
+        material = file.by_type("IfcMaterial")[0]
+        elements = ifcopenshell.util.element.get_elements_by_material(file, material)
     """
     results = set()
     for inverse in ifc_file.get_inverse(material):
@@ -229,9 +233,9 @@ def get_elements_by_style(ifc_file, style):
     :return: The elements related to the style
 
     Example::
-    style = file.by_type("IfcSurfaceStyle")[0]
-    elements = ifcopenshell.util.element.get_elements_by_style(file, style)
 
+        style = file.by_type("IfcSurfaceStyle")[0]
+        elements = ifcopenshell.util.element.get_elements_by_style(file, style)
     """
     results = set()
     inverses = list(ifc_file.get_inverse(style))
@@ -482,6 +486,15 @@ def remove_deep2(ifc_file, element, also_consider=[], do_not_delete=[]):
 
 
 def copy(ifc_file, element):
+    """
+    Copy a single element. Any referenced elements are not copied.
+
+    GlobalIds are regenerated.
+
+    :param ifc_file: The IFC file object
+    :param element: The IFC element to copy
+    :return: The newly copied element
+    """
     new = ifc_file.create_entity(element.is_a())
     for i, attribute in enumerate(element):
         if attribute is None:
@@ -493,16 +506,33 @@ def copy(ifc_file, element):
     return new
 
 
-def copy_deep(ifc_file, element):
+def copy_deep(ifc_file, element, exclude=None):
+    """
+    Recursively copy an element and all of its directly related subelements.
+
+    GlobalIds are regenerated.
+
+    :param ifc_file: The IFC file object
+    :param element: The IFC element to copy
+    :param exclude: An optional list of strings of IFC class names to not copy.
+        If any of the subelement is this class, it will not be copied and the
+        original instance will be referenced.
+    :return: The newly copied element
+    """
     new = ifc_file.create_entity(element.is_a())
     for i, attribute in enumerate(element):
         if attribute is None:
             continue
         if isinstance(attribute, ifcopenshell.entity_instance):
-            attribute = copy_deep(ifc_file, attribute)
+            if not exclude or (exclude and not any([attribute.is_a(e) for e in exclude])):
+                attribute = copy_deep(ifc_file, attribute, exclude=exclude)
         elif isinstance(attribute, tuple) and attribute and isinstance(attribute[0], ifcopenshell.entity_instance):
-            attribute = list(attribute)
+            if not exclude or (exclude and not any([attribute[0].is_a(e) for e in exclude])):
-            for j, item in enumerate(attribute):
+                attribute = list(attribute)
-                attribute[j] = copy_deep(ifc_file, item)
+                for j, item in enumerate(attribute):
-        new[i] = attribute
+                    attribute[j] = copy_deep(ifc_file, item, exclude=exclude)
+        if new.attribute_name(i) == "GlobalId":
+            new[i] = ifcopenshell.guid.new()
+        else:
+            new[i] = attribute
     return new

src/ifcopenshell-python/test/util/test_element.py

@@ -668,6 +668,7 @@ class TestCopyDeepIFC4(test.bootstrap.IFC4):
         element = self.file.createIfcWall(GlobalId="id", Name="name", OwnerHistory=owner)
         element2 = subject.copy_deep(self.file, element)
         assert element.OwnerHistory != element2.OwnerHistory
+        assert element.GlobalId != element2.GlobalId
         assert element.OwnerHistory.State == element2.OwnerHistory.State
 
     def test_copying_an_element_recursively_even_if_references_are_aggregated(self):
@@ -677,3 +678,17 @@ class TestCopyDeepIFC4(test.bootstrap.IFC4):
         rel2 = subject.copy_deep(self.file, rel)
         assert rel.RelatedObjects != rel2.RelatedObjects
         assert rel.RelatedObjects[0].Name == rel2.RelatedObjects[0].Name
+
+    def test_copying_an_element_recursively_with_an_exclude_filter(self):
+        owner = self.file.createIfcOwnerHistory()
+        owner.State = "READWRITE"
+        element = self.file.createIfcWall(GlobalId="id", Name="name", OwnerHistory=owner)
+        element2 = subject.copy_deep(self.file, element, exclude=["IfcOwnerHistory"])
+        assert element.OwnerHistory == element2.OwnerHistory
+
+    def test_copying_an_element_recursively_with_aggregates_with_an_exclude_filter(self):
+        element = self.file.createIfcWall(Name="name")
+        rel = self.file.createIfcRelAggregates()
+        rel.RelatedObjects = [element]
+        rel2 = subject.copy_deep(self.file, rel, exclude=["IfcWall"])
+        assert rel.RelatedObjects == rel2.RelatedObjects