Fix #3578. Support querying surface styles in tools like IfcCSV.

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

@@ -339,6 +339,8 @@ def get_material(element, should_skip_usage=False, should_inherit=True):
     The material may be a single material, material set (layered, profiled, or
     constituent), or a material set usage.
 
+    :param element: The element to get the material of.
+    :type element: ifcopenshell.entity_instance.entity_instance
     :param should_skip_usage: If set to True, if the material is a material set
         usage, the material set itself will be returned. Useful if you don't
         care about occurrence usage parameters. If False, the usage will be
@@ -378,6 +380,8 @@ def get_materials(element, should_inherit=True):
     If the element has a material set, the individual materials of that set are
     returned as a list.
 
+    :param element: The element to get the materials of.
+    :type element: ifcopenshell.entity_instance.entity_instance
     :param should_inherit: If True, any inherited materials from associated
         types will be considered.
     :return: The associated materials of the element.
@@ -403,6 +407,51 @@ def get_materials(element, should_inherit=True):
         return [c.Material for c in material.MaterialConstituents]
 
 
+def get_styles(element):
+    """Retrieves the styles used in an element's representation.
+
+    Styles may be retreived from the material or the body representation.
+
+    :param element: The element to get the styles of.
+    :type element: ifcopenshell.entity_instance.entity_instance
+    :return: A list of surface styles
+    :rtype: list[ifcopenshell.entity_instance.entity_instance]
+
+    Example:
+
+    .. code:: python
+
+        wall = file.by_type("IfcWall")[0]
+        styles = ifcopenshell.util.element.get_styles(wall)
+    """
+    styles = []
+
+    materials = ifcopenshell.util.element.get_materials(element)
+    for material in materials:
+        for material_definition_representation in material.HasRepresentation or []:
+            for representation in material_definition_representation.Representations:
+                for item in representation.Items:
+                    styles.extend([s for s in item.Styles if s.is_a("IfcSurfaceStyle")])
+
+    body = ifcopenshell.util.representation.get_representation(element, "Model", "Body", "MODEL_VIEW")
+    if not body:
+        return styles
+
+    for representation in [body]:
+        queue = list(representation.Items)
+        while queue:
+            item = queue.pop()
+            if item.is_a("IfcMappedItem"):
+                queue.extend(item.MappingSource.MappedRepresentation.Items)
+            if item.is_a("IfcBooleanResult"):
+                queue.append(item.FirstOperand)
+                queue.append(item.SecondOperand)
+            if item.StyledByItem:
+                styles.extend([s for s in item.StyledByItem[0].Styles if s.is_a("IfcSurfaceStyle")])
+    return styles
+
+
+
 def get_elements_by_material(ifc_file, material):
     """Retrieves the elements related to a material.
 

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

@@ -520,6 +520,10 @@ class Selector:
                 value = ifcopenshell.util.element.get_type(value)
             elif key in ("material", "mat"):
                 value = ifcopenshell.util.element.get_material(value, should_skip_usage=True)
+            elif key in ("materials", "mats"):
+                value = ifcopenshell.util.element.get_materials(value)
+            elif key == "styles":
+                value = ifcopenshell.util.element.get_styles(value)
             elif key in ("item", "i"):
                 if value.is_a("IfcMaterialLayerSet"):
                     value = value.MaterialLayers

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

@@ -386,6 +386,53 @@ class TestGetMaterial(test.bootstrap.IFC4):
         assert subject.get_material(element, should_inherit=False) is None
 
 
+class TestGetMaterials(test.bootstrap.IFC4):
+    def test_getting_the_materials_of_a_product(self):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        material = ifcopenshell.api.run("material.add_material", self.file)
+        ifcopenshell.api.run("material.assign_material", self.file, product=element, material=material)
+        assert subject.get_materials(element) == [material]
+
+
+class TestGetStyles(test.bootstrap.IFC4):
+    def test_getting_the_styles_of_a_product(self):
+        ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcProject")
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        assert subject.get_styles(element) == []
+
+        model = ifcopenshell.api.run("context.add_context", self.file, context_type="Model")
+        body = ifcopenshell.api.run("context.add_context", self.file,
+            context_type="Model", context_identifier="Body", target_view="MODEL_VIEW", parent=model)
+
+        material = ifcopenshell.api.run("material.add_material", self.file)
+        ifcopenshell.api.run("material.assign_material", self.file, product=element, material=material)
+
+        style = ifcopenshell.api.run("style.add_style", self.file)
+        ifcopenshell.api.run("style.add_surface_style", self.file,
+            style=style, ifc_class="IfcSurfaceStyleShading", attributes={
+                "SurfaceColour": { "Name": None, "Red": 1.0, "Green": 0.8, "Blue": 0.8 },
+                "Transparency": 0., # 0 is opaque, 1 is transparent
+            })
+        ifcopenshell.api.run("style.assign_material_style", self.file, material=material, style=style, context=body)
+
+        assert subject.get_styles(element) == [style]
+
+        style2 = ifcopenshell.api.run("style.add_style", self.file)
+        ifcopenshell.api.run("style.add_surface_style", self.file,
+            style=style2, ifc_class="IfcSurfaceStyleShading", attributes={
+                "SurfaceColour": { "Name": None, "Red": 1.0, "Green": 0.8, "Blue": 0.8 },
+                "Transparency": 0., # 0 is opaque, 1 is transparent
+            })
+
+        representation = ifcopenshell.api.run("geometry.add_wall_representation", self.file,
+            context=body, length=5, height=3, thickness=0.118)
+
+        ifcopenshell.api.run("geometry.assign_representation", self.file, product=element, representation=representation)
+        ifcopenshell.api.run("style.assign_representation_styles", self.file, shape_representation=representation, styles=[style2])
+
+        assert subject.get_styles(element) == [style, style2]
+
+
 class TestGetElementsByMaterial(test.bootstrap.IFC4):
     def test_getting_elements_of_a_material(self):
         element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")