Add support for connecting/disconnecting paths in API

src/ifcopenshell-python/ifcopenshell/api/geometry/connect_path.py

@@ -0,0 +1,65 @@
+# 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 ifcopenshell
+import ifcopenshell.api
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {
+            "relating_element": None,
+            "related_element": None,
+            "relating_connection": "NOTDEFINED",
+            "related_connection": "NOTDEFINED",
+        }
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        existing_connection = [
+            r
+            for r in self.settings["relating_element"].ConnectedTo
+            if r.RelatedElement == self.settings["related_element"]
+        ]
+
+        if existing_connection:
+            existing_connection = existing_connection[0]
+            if existing_connection.RelatingConnectionType != self.settings["relating_connection"]:
+                existing_connection.RelatingConnectionType = self.settings["relating_connection"]
+            if existing_connection.RelatedConnectionType != self.settings["related_connection"]:
+                existing_connection.RelatedConnectionType = self.settings["related_connection"]
+            return existing_connection[0]
+
+        if [
+            r
+            for r in self.settings["related_element"].ConnectedTo
+            if r.RelatedElement == self.settings["relating_element"]
+        ]:
+            # No cyclical connections allowed, I assume
+            return
+
+        return self.file.createIfcRelConnectsPathElements(
+            ifcopenshell.guid.new(),
+            OwnerHistory=ifcopenshell.api.run("owner.create_owner_history", self.file),
+            RelatingElement=self.settings["relating_element"],
+            RelatedElement=self.settings["related_element"],
+            RelatingConnectionType=self.settings["relating_connection"],
+            RelatedConnectionType=self.settings["related_connection"],
+        )

src/ifcopenshell-python/ifcopenshell/api/geometry/disconnect_path.py

@@ -0,0 +1,41 @@
+# 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 ifcopenshell
+import ifcopenshell.api
+
+
+class Usecase:
+    def __init__(self, file, **settings):
+        self.file = file
+        self.settings = {
+            "relating_element": None,
+            "related_element": None,
+        }
+        for key, value in settings.items():
+            self.settings[key] = value
+
+    def execute(self):
+        existing_connection = [
+            r
+            for r in self.settings["relating_element"].ConnectedTo
+            if r.RelatedElement == self.settings["related_element"]
+        ]
+
+        if existing_connection:
+            self.file.remove(existing_connection[0])

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

@@ -398,8 +398,7 @@ def get_parts(element):
 def replace_attribute(element, old, new):
     for i, attribute in enumerate(element):
         if has_element_reference(attribute, old):
-            new_attribute = element.walk(lambda v: v == old, lambda v: new, attribute)
+            element[i] = element.walk(lambda v: v == old, lambda v: new, attribute)
-            element[i] = new_attribute
 
 
 def has_element_reference(value, element):

src/ifcopenshell-python/test/api/geometry/test_connect_path.py

@@ -0,0 +1,55 @@
+# 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 test.bootstrap
+import ifcopenshell.api
+
+
+class TestConnectPath(test.bootstrap.IFC4):
+    def test_connecting_a_path(self):
+        wall1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        wall2 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        rel = ifcopenshell.api.run(
+            "geometry.connect_path",
+            self.file,
+            relating_element=wall1,
+            related_element=wall2,
+            relating_connection="ATSTART",
+            related_connection="ATEND",
+        )
+        assert rel.is_a("IfcRelConnectsPathElements")
+        assert rel.RelatingElement == wall1
+        assert rel.RelatedElement == wall2
+        assert rel.RelatingConnectionType == "ATSTART"
+        assert rel.RelatedConnectionType == "ATEND"
+
+    def test_doing_nothing_if_the_element_is_already_connected(self):
+        wall1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        wall2 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run("geometry.connect_path", self.file, relating_element=wall1, related_element=wall2)
+        total_elements = len([e for e in self.file])
+        ifcopenshell.api.run("geometry.connect_path", self.file, relating_element=wall1, related_element=wall2)
+        assert len([e for e in self.file]) == total_elements
+
+    def test_preventing_cyclical_connections(self):
+        wall1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        wall2 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run("geometry.connect_path", self.file, relating_element=wall1, related_element=wall2)
+        total_elements = len([e for e in self.file])
+        ifcopenshell.api.run("geometry.connect_path", self.file, relating_element=wall2, related_element=wall1)
+        assert len([e for e in self.file]) == total_elements

src/ifcopenshell-python/test/api/geometry/test_disconnect_path.py

@@ -0,0 +1,44 @@
+# 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 test.bootstrap
+import ifcopenshell.api
+
+
+class TestDisconnectPath(test.bootstrap.IFC4):
+    def test_disconnecting_a_path(self):
+        wall1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        wall2 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run("geometry.connect_path", self.file, relating_element=wall1, related_element=wall2)
+        ifcopenshell.api.run("geometry.disconnect_path", self.file, relating_element=wall1, related_element=wall2)
+        assert not self.file.by_type("IfcRelConnectsPathElements")
+
+    def test_doing_nothing_if_there_is_no_connection(self):
+        wall1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        wall2 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        total_elements = len([e for e in self.file])
+        ifcopenshell.api.run("geometry.disconnect_path", self.file, relating_element=wall1, related_element=wall2)
+        assert len([e for e in self.file]) == total_elements
+
+    def test_that_order_matters(self):
+        wall1 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        wall2 = ifcopenshell.api.run("root.create_entity", self.file, ifc_class="IfcWall")
+        ifcopenshell.api.run("geometry.connect_path", self.file, relating_element=wall1, related_element=wall2)
+        total_elements = len([e for e in self.file])
+        ifcopenshell.api.run("geometry.disconnect_path", self.file, relating_element=wall2, related_element=wall1)
+        assert len([e for e in self.file]) == total_elements