Selector now uses classmethods to make it easier for scriptwriters to use

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

@@ -23,8 +23,9 @@ import lark
 
 
 class Selector:
-    def parse(self, ifc_file, query):
+    @classmethod
-        self.file = ifc_file
+    def parse(cls, ifc_file, query):
+        cls.file = ifc_file
 
         l = lark.Lark(
             """start: query (lfunction query)*
@@ -82,13 +83,14 @@ class Selector:
         )
 
         start = l.parse(query)
-        return self.get_group(start)
+        return cls.get_group(start)
 
-    def get_group(self, group):
+    @classmethod
+    def get_group(cls, group):
         lfunction = None
         for child in group.children:
             if child.data == "query":
-                new_results = self.get_query(child)
+                new_results = cls.get_query(child)
                 if not lfunction:
                     results = new_results
                 elif lfunction == "or":
@@ -100,14 +102,16 @@ class Selector:
                 lfunction = child.children[0].data
         return results
 
-    def get_query(self, query):
+    @classmethod
+    def get_query(cls, query):
         for child in query.children:
             if child.data == "selector":
-                return self.get_selector(child)
+                return cls.get_selector(child)
             elif child.data == "group":
-                return self.get_group(child)
+                return cls.get_group(child)
 
-    def get_selector(self, selector):
+    @classmethod
+    def get_selector(cls, selector):
         if len(selector.children) == 1:
             inverse_relationship = None
             class_or_guid_selector = selector.children[0]
@@ -116,15 +120,16 @@ class Selector:
             class_or_guid_selector = selector.children[1]
 
         if class_or_guid_selector.data == "class_selector":
-            results = self.get_class_selector(class_or_guid_selector)
+            results = cls.get_class_selector(class_or_guid_selector)
         elif class_or_guid_selector.data == "guid_selector":
-            results = self.get_guid_selector(class_or_guid_selector)
+            results = cls.get_guid_selector(class_or_guid_selector)
 
         if not inverse_relationship:
             return results
-        return self.parse_inverse_relationship(results, inverse_relationship.children[0].data)
+        return cls.parse_inverse_relationship(results, inverse_relationship.children[0].data)
 
-    def parse_inverse_relationship(self, elements, inverse_relationship):
+    @classmethod
+    def parse_inverse_relationship(cls, elements, inverse_relationship):
         results = []
         for element in elements:
             if inverse_relationship == "types":
@@ -140,20 +145,22 @@ class Selector:
                     results.append(relationship.RelatedBuildingElement)
         return results
 
-    def get_class_selector(self, class_selector):
+    @classmethod
+    def get_class_selector(cls, class_selector):
         if class_selector.children[0] == "COBie":
-            elements = ifcopenshell.util.fm.get_cobie_components(self.file)
+            elements = ifcopenshell.util.fm.get_cobie_components(cls.file)
         elif class_selector.children[0] == "COBieType":
-            elements = ifcopenshell.util.fm.get_cobie_types(self.file)
+            elements = ifcopenshell.util.fm.get_cobie_types(cls.file)
         elif class_selector.children[0] == "FMHEM":
-            elements = ifcopenshell.util.fm.get_fmhem_types(self.file)
+            elements = ifcopenshell.util.fm.get_fmhem_types(cls.file)
         else:
-            elements = self.file.by_type(class_selector.children[0])
+            elements = cls.file.by_type(class_selector.children[0])
         if len(class_selector.children) > 1 and class_selector.children[1].data == "filter":
-            return self.filter_elements(elements, class_selector.children[1])
+            return cls.filter_elements(elements, class_selector.children[1])
         return elements
 
-    def filter_elements(self, elements, filter_rule):
+    @classmethod
+    def filter_elements(cls, elements, filter_rule):
         results = []
         key = filter_rule.children[0].children[0]
         if not isinstance(key, str):
@@ -163,14 +170,15 @@ class Selector:
             comparison = filter_rule.children[1].children[0].data
             value = filter_rule.children[2].children[0][1:-1]
         for element in elements:
-            element_value = self.get_element_value(element, key)
+            element_value = cls.get_element_value(element, key)
             if element_value is None:
                 continue
-            if not comparison or self.filter_element(element, element_value, comparison, value):
+            if not comparison or cls.filter_element(element, element_value, comparison, value):
                 results.append(element)
         return results
 
-    def get_element_value(self, element, key):
+    @classmethod
+    def get_element_value(cls, element, key):
         if "." in key and key.split(".")[0] == "type":
             try:
                 element = ifcopenshell.util.element.get_type(element)
@@ -206,7 +214,8 @@ class Selector:
             if pset_name in psets and prop in psets[pset_name]:
                 return psets[pset_name][prop]
 
-    def filter_element(self, element, element_value, comparison, value):
+    @classmethod
+    def filter_element(cls, element, element_value, comparison, value):
         if comparison == "equal":
             return str(element_value) == value
         elif comparison == "contains":
@@ -221,5 +230,6 @@ class Selector:
             return element_value <= float(value)
         return False
 
-    def get_guid_selector(self, guid_selector):
+    @classmethod
-        return [self.file.by_id(guid_selector.children[0])]
+    def get_guid_selector(cls, guid_selector):
+        return [cls.file.by_id(guid_selector.children[0])]

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

@@ -0,0 +1,47 @@
+# 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 pytest
+import test.bootstrap
+import ifcopenshell.api
+import ifcopenshell.util.selector as subject
+
+
+class TestSelector(test.bootstrap.IFC4):
+    def test_selecting_by_class(self):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcSlab")
+        assert subject.Selector.parse(self.file, ".IfcWall") == [element]
+
+    def test_selecting_by_globalid(self):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcSlab")
+        assert subject.Selector.parse(self.file, f"#{element.GlobalId}") == [element]
+
+    def test_selecting_by_attribute(self):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        element.Name = "Foobar"
+        ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcSlab")
+        assert subject.Selector.parse(self.file, '.IfcElement[Name="Foobar"]') == [element]
+        assert subject.Selector.parse(self.file, '.IfcElement[Name="Foobaz"]') == []
+
+    def test_selecting_by_string_property(self):
+        element = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        pset = ifcopenshell.api.run("pset.add_pset", self.file, product=element, name="Foo_Bar")
+        ifcopenshell.api.run("pset.edit_pset", self.file, pset=pset, properties={"Foo": "Bar"})
+        assert subject.Selector.parse(self.file, '.IfcElement[Foo_Bar.Foo="Bar"]') == [element]