add depreciation.attribute_renamed

1 files changed, 45 insertions, 0 deletions

diff --git a/logilab/common/deprecation.py b/logilab/common/deprecation.py
index 3cfdff0..d45424d 100644
--- a/logilab/common/deprecation.py
+++ b/logilab/common/deprecation.py
@@ -190,6 +190,51 @@ def moved(modpath, objname):
 moved.__doc__ = _defaultdeprecator.moved.__doc__
 
 
+def attribute_renamed(old_name, new_name):
+    """
+    class decorator to allow getting backward compatibility for renamed attributes.
+
+    >>> @attribute_renamed(old_name="old", new_name="new")
+    ... class SomeClass:
+    ...     def __init__(self):
+    ...         self.new = 42
+
+    >>> some_class = SomeClass()
+    >>> print(some_class.old)
+    sample.py:15: DeprecationWarning: SomeClass.old has been renamed and is deprecated, use SomeClass.new instead
+      print(some_class.old)
+    42
+    >>> some_class.old = 43
+    sample.py:16: DeprecationWarning: SomeClass.old has been renamed and is deprecated, use SomeClass.new instead
+      some_class.old = 43
+    >>> some_class.old == some_class.new
+    True
+    """
+    def _class_wrap(klass):
+        reason = (
+            f"{klass.__name__}.{old_name} has been renamed and is deprecated, use "
+            f"{klass.__name__}.{new_name} instead"
+        )
+
+        def _get_old(self):
+            warn(reason, DeprecationWarning, stacklevel=2)
+            return getattr(self, new_name)
+
+        def _set_old(self, value):
+            warn(reason, DeprecationWarning, stacklevel=2)
+            setattr(self, new_name, value)
+
+        def _del_old(self):
+            warn(reason, DeprecationWarning, stacklevel=2)
+            delattr(self, new_name)
+
+        setattr(klass, old_name, property(_get_old, _set_old, _del_old))
+
+        return klass
+
+    return _class_wrap
+
+
 def renamed(old_name, new_function):
     """use to tell that a callable has been renamed.