Remove empty IfcDocumentInformationRelationship #3581

src/ifcopenshell-python/ifcopenshell/api/document/remove_information.py

@@ -46,10 +46,17 @@ class Usecase:
     def execute(self):
         for reference in self.settings["information"].HasDocumentReferences or []:
             ifcopenshell.api.run("document.remove_reference", self.file, reference=reference)
+
         for rel in self.settings["information"].IsPointer or []:
             for information in rel.RelatedDocuments:
                 ifcopenshell.api.run("document.remove_information", self.file, information=information)
             self.file.remove(rel)
+
+        # remove IfcDocumentInformationRelationship so it won't become invalid
+        for rel in self.settings["information"].IsPointedTo or []:
+            if rel.RelatedDocuments == (self.settings["information"],):
+                self.file.remove(rel)
+
         for rel in self.settings["information"].DocumentInfoForObjects or []:
             self.file.remove(rel)
         self.file.remove(self.settings["information"])

src/ifcopenshell-python/test/api/document/test_remove_information.py

@@ -37,6 +37,19 @@ class TestRemoveInformation(test.bootstrap.IFC4):
         assert len(self.file.by_type("IfcDocumentReference")) == 0
         assert len(self.file.by_type("IfcRelAssociatesDocument")) == 0
 
+        # test removing relationship to another information if it was the only relating element
+        information = ifcopenshell.api.run("document.add_information", self.file, parent=None)
+        information1 = ifcopenshell.api.run("document.add_information", self.file, parent=information)
+        information2 = ifcopenshell.api.run("document.add_information", self.file, parent=information)
+
+        ifcopenshell.api.run("document.remove_information", self.file, information=information1)
+        assert len(self.file.by_type("IfcDocumentInformation")) == 2
+        assert len(self.file.by_type("IfcDocumentInformationRelationship")) == 1
+
+        ifcopenshell.api.run("document.remove_information", self.file, information=information2)
+        assert len(self.file.by_type("IfcDocumentInformation")) == 1
+        assert len(self.file.by_type("IfcDocumentInformationRelationship")) == 0
+
     def test_removing_all_subdocuments_and_their_references_too(self):
         project = self.file.createIfcProject()
         information = ifcopenshell.api.run("document.add_information", self.file, parent=None)