checkpoint

src/hdmf/common/table.py

@@ -279,13 +279,16 @@ def __gather_columns(cls, name, bases, classdict):
             raise TypeError(msg)
 
         if len(bases) and 'DynamicTable' in globals():
-            for item in bases:
+            for item in bases[::-1]: # reverse the bases tuple as the code suggest it should be last
                 if issubclass(item, Container):
                     try:
                         if item.__columns__ is not cls.__columns__:
+                            if cls.__name__ == 'PlaneSegmentation':
+                                breakpoint()
                             new_columns = list(cls.__columns__)
                             new_columns[0:0] = item.__columns__  # prepend superclass columns to new_columns
                             cls.__columns__ = tuple(new_columns)
+                            break
                     except AttributeError:  # raises error when "__columns__" is not an attr of item
                         continue
 

tests/unit/helpers/utils.py

@@ -653,3 +653,28 @@ class CustomSpecNamespace(SpecNamespace):
     @classmethod
     def types_key(cls):
         return cls.__types_key
+
+class FooExtendDynamicTable0(DynamicTable):
+    """
+    Within PyNWB, PlaneSegmentation extends DynamicTable and sets __columns__. This class is a helper
+    class for testing and is directly meant to test __gather_columns, i.e., class generation, downstream.
+    """
+    __columns__ = (
+        {'name': 'col1', 'description': '...'},
+        {'name': 'col2', 'description': '...'},
+    )
+
+
+class FooExtendDynamicTable1(FooExtendDynamicTable0):
+    """
+    In extensions, users can create new classes that inherit from classes that inherit from DynamicTable.
+    This is a helper class for testing and is directly meant to test __gather_columns, i.e.,
+    class generation, downstream.
+    """
+    __columns__ = (
+        {'name': 'col3', 'description': '...'},
+        {'name': 'col4', 'description': '...'},
+    )
+
+class FooExtendDynamicTable2(FooExtendDynamicTable2):
+    pass