eds: Add first-class support for CiA 306 ObjFlags and Denotation

ObjFlags (UNSIGNED32 bitfield) and Denotation (DCF-only string) are
standard CiA 306 fields that are now parsed and exported explicitly.

Changes:
  * ODVariable, ODRecord and ODArray gain an obj_flags: int = 0 attribute.
  * ODVariable gains a denotation: str = '' attribute.
  * _get_obj_flags() helper reads and validates the ObjFlags integer value.
  * ObjFlags is parsed for VAR/DOMAIN (via build_variable), ARRAY and RECORD.
  * ObjFlags is exported whenever non-zero.
  * Denotation is read in build_variable() and written only in DCF mode
    (device_commisioning=True), matching the CiA 306 specification.
  * Adds test object 0x3060 (ObjFlags=0x1) to sample.eds and four new tests
    covering read, round-trip and DCF export for both fields.

Co-authored-by: FedericoSpada <FedericoSpada@users.noreply.github.com>

Author: bizfsc

canopen/objectdictionary/__init__.py

@@ -207,6 +207,8 @@ def __init__(self, name: str, index: int):
         self.name = name
         #: Storage location of index
         self.storage_location = None
+        #: CiA 306 ObjFlags bitfield
+        self.obj_flags: int = 0
         self.subindices = {}
         self.names = {}
 
@@ -266,6 +268,8 @@ def __init__(self, name: str, index: int):
         self.name = name
         #: Storage location of index
         self.storage_location = None
+        #: CiA 306 ObjFlags bitfield
+        self.obj_flags: int = 0
         self.subindices = {}
         self.names = {}
 
@@ -372,6 +376,10 @@ def __init__(self, name: str, index: int, subindex: int = 0):
         self.bit_definitions: dict[str, list[int]] = {}
         #: Storage location of index
         self.storage_location = None
+        #: CiA 306 ObjFlags bitfield
+        self.obj_flags: int = 0
+        #: CiA 306 Denotation string (DCF only)
+        self.denotation: str = ""
         #: Can this variable be mapped to a PDO
         self.pdo_mappable = False
 

canopen/objectdictionary/eds.py

@@ -139,14 +139,17 @@ def import_eds(source, node_id):
                 arr.add_member(last_subindex)
                 arr.add_member(build_variable(eds, section, node_id, index, 1))
                 arr.storage_location = storage_location
+                arr.obj_flags = _get_obj_flags(eds, section)
                 od.add_object(arr)
             elif object_type == objectcodes.ARRAY:
                 arr = ODArray(name, index)
                 arr.storage_location = storage_location
+                arr.obj_flags = _get_obj_flags(eds, section)
                 od.add_object(arr)
             elif object_type == objectcodes.RECORD:
                 record = ODRecord(name, index)
                 record.storage_location = storage_location
+                record.obj_flags = _get_obj_flags(eds, section)
                 od.add_object(record)
 
             continue
@@ -252,6 +255,15 @@ def _revert_variable(var_type, value):
         return f"0x{value:02X}"
 
 
+def _get_obj_flags(eds, section):
+    if eds.has_option(section, "ObjFlags"):
+        try:
+            return int(eds.get(section, "ObjFlags"), 0)
+        except ValueError:
+            pass
+    return 0
+
+
 def build_variable(eds, section, node_id, index, subindex=0):
     """Creates a object dictionary entry.
     :param eds: String stream of the eds file
@@ -330,6 +342,9 @@ def build_variable(eds, section, node_id, index, subindex=0):
             var.unit = eds.get(section, "Unit")
         except ValueError:
             pass
+    var.obj_flags = _get_obj_flags(eds, section)
+    if eds.has_option(section, "Denotation"):
+        var.denotation = eds.get(section, "Denotation")
     return var
 
 
@@ -404,12 +419,19 @@ def export_variable(var, eds):
         if getattr(var, 'unit', '') != '':
             eds.set(section, "Unit", var.unit)
 
+        if getattr(var, 'obj_flags', 0) != 0:
+            eds.set(section, "ObjFlags", f"0x{var.obj_flags:X}")
+        if device_commisioning and getattr(var, 'denotation', '') != '':
+            eds.set(section, "Denotation", var.denotation)
+
     def export_record(var, eds):
         section = f"{var.index:04X}"
         export_common(var, eds, section)
         eds.set(section, "SubNumber", f"0x{len(var.subindices):X}")
         ot = objectcodes.RECORD if isinstance(var, ODRecord) else objectcodes.ARRAY
         eds.set(section, "ObjectType", f"0x{ot:X}")
+        if getattr(var, 'obj_flags', 0) != 0:
+            eds.set(section, "ObjFlags", f"0x{var.obj_flags:X}")
         for i in var:
             export_variable(var[i], eds)
 

test/sample.eds

@@ -1017,3 +1017,11 @@ PDOMapping=0x0
 Factor=ERROR
 Description=
 Unit=
+
+[3060]
+ParameterName=Object with ObjFlags
+ObjectType=0x7
+DataType=0x0007
+AccessType=rw
+PDOMapping=0
+ObjFlags=0x1

test/test_eds.py

@@ -359,6 +359,46 @@ def verify_od(self, source, doctype):
 
                 self.assertEqual(self.od.comments, exported_od.comments)
 
+    def test_reading_obj_flags(self):
+        var = self.od[0x3060]
+        self.assertIsInstance(var, canopen.objectdictionary.ODVariable)
+        self.assertEqual(var.obj_flags, 0x1)
+
+    def test_reading_obj_flags_default(self):
+        """Standard objects without ObjFlags must have obj_flags == 0."""
+        var = self.od[0x1017]  # Producer heartbeat time — no ObjFlags in sample.eds
+        self.assertEqual(var.obj_flags, 0)
+
+    def test_roundtrip_obj_flags(self):
+        import io
+        with io.StringIO() as dest:
+            canopen.export_od(self.od, dest, 'eds')
+            dest.name = 'mock.eds'
+            dest.seek(0)
+            od2 = canopen.import_od(dest)
+        self.assertEqual(od2[0x3060].obj_flags, 0x1)
+        self.assertEqual(od2[0x1017].obj_flags, 0)
+
+    def test_denotation_roundtrip_dcf(self):
+        import io
+        self.od[0x3060].denotation = 'FlaggedObject'
+        with io.StringIO() as dest:
+            canopen.export_od(self.od, dest, 'dcf')
+            dest.name = 'mock.dcf'
+            dest.seek(0)
+            od2 = canopen.import_od(dest)
+        self.assertEqual(od2[0x3060].denotation, 'FlaggedObject')
+
+    def test_denotation_not_exported_in_eds_mode(self):
+        import io
+        self.od[0x3060].denotation = 'ShouldNotAppear'
+        with io.StringIO() as dest:
+            canopen.export_od(self.od, dest, 'eds')
+            dest.name = 'mock.eds'
+            dest.seek(0)
+            od2 = canopen.import_od(dest)
+        self.assertEqual(od2[0x3060].denotation, '')
+
 
 if __name__ == "__main__":
     unittest.main()