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

3 files changed, 40 insertions, 8 deletions

diff --git a/docs/settings.txt b/docs/settings.txt
index 3f83ea0e69..bf333da1b8 100644
--- a/docs/settings.txt
+++ b/docs/settings.txt
@@ -621,6 +621,18 @@ Default: ``('django.core.template.loaders.filesystem.load_template_source',)``
 A tuple of callables (as strings) that know how to import templates from
 various sources. See the `template documentation`_.
 
+TEMPLATE_STRING_IF_INVALID
+--------------------------
+
+Default: ``''`` (Empty string)
+
+**New in Django development version.**
+
+Output, as a string, that the template system should use for invalid (e.g.
+misspelled) variables. See `How invalid variables are handled`_.
+
+.. _How invalid variables are handled: http://www.djangoproject.com/documentation/templates_python/#how-invalid-variables-are-handled
+
 TIME_FORMAT
 -----------
 
diff --git a/docs/templates.txt b/docs/templates.txt
index 20fe62bbae..d210ec2f77 100644
--- a/docs/templates.txt
+++ b/docs/templates.txt
@@ -70,6 +70,12 @@ Use a dot (``.``) to access attributes of a variable.
 In the above example, ``{{ section.title }}`` will be replaced with the
 ``title`` attribute of the ``section`` object.
 
+In Django 0.91, if you use a variable that doesn't exist, it will be silently
+ignored; the variable will be replaced by nothingness. 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.
+
 If you use a variable that doesn't exist, it will be silently ignored. The
 variable will be replaced by nothingness.
 
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
 ----------------------------