Save loaded paths to linked IFC models in IFC #5899

Short demo - https://imgur.com/a/3LIt9Sr

src/bonsai/test/tool/test_project.py

@@ -18,6 +18,8 @@
 
 import bpy
 import ifcopenshell
+import ifcopenshell.api.document
+import ifcopenshell.api.root
 import bonsai.core.tool
 import bonsai.tool as tool
 import tempfile
@@ -238,3 +240,108 @@ class TestLoadProject(NewFile):
         assert not tool.Ifc.get()
         assert bpy.data.objects["IfcWall/Wall"]
         assert tool.Blender.is_valid_data_block(monkey)
+
+
+class TestLoadLinkedModels(NewFile):
+    def test_load_linked_models_no_document(self):
+        links = bpy.context.scene.BIMProjectProperties.links
+        ifc = ifcopenshell.file()
+        tool.Ifc.set(ifc)
+        subject.load_linked_models_from_ifc()
+        assert len(links) == 0
+
+    def test_load_linked_models_document_no_references(self):
+        ifc = ifcopenshell.file()
+        links = bpy.context.scene.BIMProjectProperties.links
+        ifcopenshell.api.root.create_entity(ifc, "IfcProject")
+        document = ifcopenshell.api.document.add_information(ifc)
+        document.Name = "BBIM_Linked_Models"
+        tool.Ifc.set(ifc)
+        subject.load_linked_models_from_ifc()
+        assert len(links) == 0
+
+    def test_load_linked_models_document_with_references(self):
+        ifc = ifcopenshell.file()
+        links = bpy.context.scene.BIMProjectProperties.links
+        ifcopenshell.api.root.create_entity(ifc, "IfcProject")
+        document = ifcopenshell.api.document.add_information(ifc)
+        document.Name = "BBIM_Linked_Models"
+        reference = ifcopenshell.api.document.add_reference(ifc, document)
+        linked_model_path = "test.ifc"
+        reference.Location = linked_model_path
+        tool.Ifc.set(ifc)
+        subject.load_linked_models_from_ifc()
+        assert len(links) == 1
+        assert links[0].name == linked_model_path
+
+
+class TestSaveLinkedModelsToIfc(NewFile):
+    def test_save_linked_models_to_ifc_no_links(self):
+        ifc = ifcopenshell.file()
+        tool.Ifc.set(ifc)
+        subject.save_linked_models_to_ifc()
+        assert len(ifc.by_type("IfcDocumentInformation")) == 0
+        assert len(ifc.by_type("IfcDocumentReference")) == 0
+
+    def test_save_linked_models_to_ifc_paths_to_add(self):
+        ifc = ifcopenshell.file()
+        ifcopenshell.api.root.create_entity(ifc, "IfcProject")
+        links = bpy.context.scene.BIMProjectProperties.links
+        link = links.add()
+        linked_model_path = "test.ifc"
+        link.name = linked_model_path
+        tool.Ifc.set(ifc)
+        subject.save_linked_models_to_ifc()
+        assert len(documents := ifc.by_type("IfcDocumentInformation")) == 1
+        assert documents[0].Name == "BBIM_Linked_Models"
+        assert len(references := ifc.by_type("IfcDocumentReference")) == 1
+        assert references[0].Location == linked_model_path
+
+    def test_save_linked_models_to_ifc_already_created_references(self):
+        ifc = ifcopenshell.file()
+        links = bpy.context.scene.BIMProjectProperties.links
+        ifcopenshell.api.root.create_entity(ifc, "IfcProject")
+
+        document = ifcopenshell.api.document.add_information(ifc)
+        document.Name = "BBIM_Linked_Models"
+        document_id = document.id()
+        reference = ifcopenshell.api.document.add_reference(ifc, document)
+        linked_model_path = "test.ifc"
+        reference.Location = linked_model_path
+        reference_id = reference.id()
+
+        link = links.add()
+        linked_model_path = "test.ifc"
+        link.name = linked_model_path
+        tool.Ifc.set(ifc)
+        subject.save_linked_models_to_ifc()
+
+        # Information and references to stay intact.
+        assert len(documents := ifc.by_type("IfcDocumentInformation")) == 1
+        assert documents[0].id() == document_id
+        assert documents[0].Name == "BBIM_Linked_Models"
+        assert len(references := ifc.by_type("IfcDocumentReference")) == 1
+        assert references[0].id() == reference_id
+        assert references[0].Location == linked_model_path
+
+    def test_save_linked_models_to_ifc_references_to_remove(self):
+        ifc = ifcopenshell.file()
+        links = bpy.context.scene.BIMProjectProperties.links
+        ifcopenshell.api.root.create_entity(ifc, "IfcProject")
+
+        document = ifcopenshell.api.document.add_information(ifc)
+        document.Name = "BBIM_Linked_Models"
+        document_id = document.id()
+        reference = ifcopenshell.api.document.add_reference(ifc, document)
+        linked_model_path = "test.ifc"
+        reference.Location = linked_model_path
+
+        tool.Ifc.set(ifc)
+        subject.save_linked_models_to_ifc()
+        links.clear()
+
+        # Remove reference for removed link.
+        assert len(documents := ifc.by_type("IfcDocumentInformation")) == 1
+        assert documents[0].id() == document_id
+        assert documents[0].Name == "BBIM_Linked_Models"
+        assert len(ifc.by_type("IfcDocumentReference")) == 0