Added django.utils.decorators, from Hugo's #580 patch. Refs #580.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@807 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/utils/decorators.py

@@ -0,0 +1,22 @@
+"Functions that help with dynamically creating decorators for views."
+
+def decorator_from_middleware(middleware_class):
+    """
+    Given a middleware class (not an instance), returns a view decorator. This
+    lets you use middleware functionality on a per-view basis.
+    """
+    def _decorator_from_middleware(view_func, *args, **kwargs):
+        middleware = middleware_class(*args, **kwargs)
+        def _wrapped_view(request, *args, **kwargs):
+            if hasattr(middleware, 'process_request'):
+                result = middleware.process_request(request)
+                if result is not None:
+                    return result
+            response = view_func(request, *args, **kwargs)
+            if hasattr(middleware, 'process_response'):
+                result = middleware.process_response(request, response)
+                if result is not None:
+                    return result
+            return response
+        return _wrapped_view
+    return _decorator_from_middleware