Created---or-nothing---filter-in-default-filters-.patch

From 99ca027e7f09c5a7dfd0e6804cc90325c223ffea Mon Sep 17 00:00:00 2001
From: Ben Spaulding <ben@benspaulding.com>
Date: Fri, 20 Mar 2009 00:17:14 -0500
Subject: [PATCH] Created ``or_nothing`` filter in default filters.

The same thing can be accomplished with the ``default``
filter and an empty argument, but that feels hacky and
it looks dirty, too.
---
 django/template/defaultfilters.py             |   11 +++++++++++
 docs/ref/templates/builtins.txt               |   15 +++++++++++++++
 tests/regressiontests/defaultfilters/tests.py |    9 +++++++++
 3 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/django/template/defaultfilters.py b/django/template/defaultfilters.py
index ff8d418..59bd0c1 100644
--- a/django/template/defaultfilters.py
+++ b/django/template/defaultfilters.py
@@ -732,6 +732,16 @@ def divisibleby(value, arg):
     return int(value) % int(arg) == 0
 divisibleby.is_safe = False
 
+def or_nothing(value):
+    """
+    Given a value of false or None, return an empty string.
+
+    False values include ``False`` and ``0``, as well as ``[]``
+    (empty list), ``()`` (empty tuple) and ``{}`` (empty dictionary).
+    """
+    return value or u''
+or_nothing.is_safe = False
+
 def yesno(value, arg=None):
     """
     Given a string mapping values for true, false and (optionally) None,
@@ -877,6 +887,7 @@ register.filter(linenumbers)
 register.filter(ljust)
 register.filter(lower)
 register.filter(make_list)
+register.filter(or_nothing)
 register.filter(phone2numeric)
 register.filter(pluralize)
 register.filter(pprint)
diff --git a/docs/ref/templates/builtins.txt b/docs/ref/templates/builtins.txt
index 17e6e8b..02cf35f 100644
--- a/docs/ref/templates/builtins.txt
+++ b/docs/ref/templates/builtins.txt
@@ -1240,6 +1240,21 @@ If ``value`` is the string ``"Joel"``, the output would be the list
 ``[u'J', u'o', u'e', u'l']``. If ``value`` is ``123``, the output will be the
 list ``[1, 2, 3]``.
 
+.. templatefilter:: or_nothing
+
+or_nothing
+~~~~~~~~~~
+
+If value evaluates to false or None, return an empty string.
+
+For example::
+
+    {{ value|or_nothing }}
+
+If ``value`` is ``False``, ``0``, ``""`` (empty string), ``[]`` (empty list),
+``()`` (empty tuple) or ``{}`` (empty dictionary) the output will be an
+empty string.
+
 .. templatefilter:: phone2numeric
 
 phone2numeric
diff --git a/tests/regressiontests/defaultfilters/tests.py b/tests/regressiontests/defaultfilters/tests.py
index a97596f..a43c2ad 100644
--- a/tests/regressiontests/defaultfilters/tests.py
+++ b/tests/regressiontests/defaultfilters/tests.py
@@ -419,6 +419,15 @@ True
 >>> divisibleby(4, 3)
 False
 
+>>> or_nothing(u"val")
+u'val'
+
+>>> or_nothing(False)
+u''
+
+>>> or_nothing(None)
+u''
+
 >>> yesno(True)
 u'yes'
 
-- 
1.6.0.2+GitX