Fix #1112. You can now tag material attributes.

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

@@ -63,6 +63,18 @@ def get_type(element):
                 return relationship.RelatingType
 
 
+def get_material(element):
+    if hasattr(element, "HasAssociations") and element.HasAssociations:
+        for relationship in element.HasAssociations:
+            if relationship.is_a("IfcRelAssociatesMaterial"):
+                return relationship.RelatingMaterial
+    relating_type = get_type(element)
+    if hasattr(relating_type, "HasAssociations") and relating_type.HasAssociations:
+        for relationship in relating_type.HasAssociations:
+            if relationship.is_a("IfcRelAssociatesMaterial"):
+                return relationship.RelatingMaterial
+
+
 def replace_attribute(element, old, new):
     for i, attribute in enumerate(element):
         if attribute == old:

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

@@ -219,6 +219,14 @@ class Selector:
             except:
                 return
             key = ".".join(key.split(".")[1:])
+        elif "." in key and key.split(".")[0] == "material":
+            try:
+                element = ifcopenshell.util.element.get_material(element)
+                if not element:
+                    return None
+            except:
+                return
+            key = ".".join(key.split(".")[1:])
         info = element.get_info()
         if key in info:
             return info[key]