Fixed #15363 -- Renamed and normalized to `get_queryset` the methods that return a QuerySet.

1 files changed, 62 insertions, 0 deletions

diff --git a/django/utils/deprecation.py b/django/utils/deprecation.py
new file mode 100644
index 0000000000..edbb5ca5ea
--- /dev/null
+++ b/django/utils/deprecation.py
@@ -0,0 +1,62 @@
+import inspect
+import warnings
+
+
+class warn_about_renamed_method(object):
+    def __init__(self, class_name, old_method_name, new_method_name, deprecation_warning):
+        self.class_name = class_name
+        self.old_method_name = old_method_name
+        self.new_method_name = new_method_name
+        self.deprecation_warning = deprecation_warning
+
+    def __call__(self, f):
+        def wrapped(*args, **kwargs):
+            warnings.warn(
+                "`%s.%s` is deprecated, use `%s` instead." %
+                (self.class_name, self.old_method_name, self.new_method_name),
+                self.deprecation_warning, 2)
+            return f(*args, **kwargs)
+        return wrapped
+
+
+class RenameMethodsBase(type):
+    """
+    Handles the deprecation paths when renaming a method.
+
+    It does the following:
+        1) Define the new method if missing and complain about it.
+        2) Define the old method if missing.
+        3) Complain whenever an old method is called.
+
+    See #15363 for more details.
+    """
+
+    renamed_methods = ()
+
+    def __new__(cls, name, bases, attrs):
+        new_class = super(RenameMethodsBase, cls).__new__(cls, name, bases, attrs)
+
+        for base in inspect.getmro(new_class):
+            class_name = base.__name__
+            for renamed_method in cls.renamed_methods:
+                old_method_name = renamed_method[0]
+                old_method = base.__dict__.get(old_method_name)
+                new_method_name = renamed_method[1]
+                new_method = base.__dict__.get(new_method_name)
+                deprecation_warning = renamed_method[2]
+                wrapper = warn_about_renamed_method(class_name, *renamed_method)
+
+                # Define the new method if missing and complain about it
+                if not new_method and old_method:
+                    warnings.warn(
+                        "`%s.%s` method should be renamed `%s`." %
+                        (class_name, old_method_name, new_method_name),
+                        deprecation_warning, 2)
+                    setattr(base, new_method_name, old_method)
+                    setattr(base, old_method_name, wrapper(old_method))
+
+                # Define the old method as a wrapped call to the new method.
+                if not old_method and new_method:
+                    setattr(base, old_method_name, wrapper(new_method))
+
+        return new_class