Added TEMPLATE_STRING_IF_INVALID setting, which specifies what the template system should output in case of invalid variables. Default is empty string (to match current behavior)

git-svn-id: http://code.djangoproject.com/svn/django/trunk@2294 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 22 insertions, 8 deletions

diff --git a/docs/templates_python.txt b/docs/templates_python.txt
index efbd648cf1..9203b92f9c 100644
--- a/docs/templates_python.txt
+++ b/docs/templates_python.txt
@@ -135,14 +135,6 @@ Here are a few examples::
     >>> t.render(c)
     "The first stooge in the list is Larry."
 
-If a variable doesn't exist, the template system fails silently. The variable
-is replaced with an empty string::
-
-    >>> t = Template("My name is {{ my_name }}.")
-    >>> c = Context({"foo": "bar"})
-    >>> t.render(c)
-    "My name is ."
-
 Method lookups are slightly more complex than the other lookup types. Here are
 some things to keep in mind:
 
@@ -193,6 +185,28 @@ some things to keep in mind:
             self.database_record.delete()
         sensitive_function.alters_data = True
 
+How invalid variables are handled
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In Django 0.91, if a variable doesn't exist, the template system fails
+silently. The variable is replaced with an empty string::
+
+    >>> t = Template("My name is {{ my_name }}.")
+    >>> c = Context({"foo": "bar"})
+    >>> t.render(c)
+    "My name is ."
+
+This applies to any level of lookup::
+
+    >>> t = Template("My name is {{ person.fname }} {{ person.lname }}.")
+    >>> c = Context({"person": {"fname": "Stan"}})
+    >>> t.render(c)
+    "My name is Stan ."
+
+In the Django development version, if a variable doesn't exist, the template
+system inserts the value of the ``TEMPLATE_STRING_IF_INVALID`` setting, which
+is set to ``''`` (the empty string) by default.
+
 Playing with Context objects
 ----------------------------