Document the fact that the {% module %} directive requires a RequestHandler.

Closes #880.

diff --git a/tornado/template.py b/tornado/template.py
index 341e07c62fda8290bf5d9d4cc16d074ede9661c4..77fd579e31d5dc76a83f10ae71e77cc7e901b2b9 100644 (file)
--- a/tornado/template.py
+++ b/tornado/template.py
@@ -169,6 +169,10 @@ with ``{# ... #}``.
 
         {% module Template("foo.html", arg=42) %}
 
+    ``UIModules`` are a feature of the `tornado.web.RequestHandler`
+    class (and specifically its ``render`` method) and will not work
+    when the template system is used on its own in other contexts.
+
 ``{% raw *expr* %}``
     Outputs the result of the given expression without autoescaping.