newforms-admin: Added some files missing from [6613]

git-svn-id: http://code.djangoproject.com/svn/django/branches/newforms-admin@6614 bcc190cf-cafb-0310-a4f2-bffc1f526a37

2 files changed, 79 insertions, 0 deletions

diff --git a/django/templatetags/cache.py b/django/templatetags/cache.py
new file mode 100644
index 0000000000..4436b15d6e
--- /dev/null
+++ b/django/templatetags/cache.py
@@ -0,0 +1,57 @@
+from django.template import Library, Node, TemplateSyntaxError
+from django.template import resolve_variable
+from django.core.cache import cache
+from django.utils.encoding import force_unicode
+
+register = Library()
+
+class CacheNode(Node):
+    def __init__(self, nodelist, expire_time, fragment_name, vary_on):
+        self.nodelist = nodelist
+        self.expire_time = expire_time
+        self.fragment_name = fragment_name
+        self.vary_on = vary_on
+
+    def render(self, context):
+        # Build a unicode key for this fragment and all vary-on's.
+        cache_key = u':'.join([self.fragment_name] + \
+            [force_unicode(resolve_variable(var, context)) for var in self.vary_on])
+        value = cache.get(cache_key)
+        if value is None:
+            value = self.nodelist.render(context)
+            cache.set(cache_key, value, self.expire_time)
+        return value
+
+def do_cache(parser, token):
+    """
+    This will cache the contents of a template fragment for a given amount
+    of time.
+
+    Usage::
+
+        {% load cache %}
+        {% cache [expire_time] [fragment_name] %}
+            .. some expensive processing ..
+        {% endcache %}
+
+    This tag also supports varying by a list of arguments::
+
+        {% load cache %}
+        {% cache [expire_time] [fragment_name] [var1] [var2] .. %}
+            .. some expensive processing ..
+        {% endcache %}
+
+    Each unique set of arguments will result in a unique cache entry.
+    """
+    nodelist = parser.parse(('endcache',))
+    parser.delete_first_token()
+    tokens = token.contents.split()
+    if len(tokens) < 3:
+        raise TemplateSyntaxError(u"'%r' tag requires at least 2 arguments." % tokens[0])
+    try:
+        expire_time = int(tokens[1])
+    except ValueError:
+        raise TemplateSyntaxError(u"First argument to '%r' must be an integer (got '%s')." % (tokens[0], tokens[1]))
+    return CacheNode(nodelist, expire_time, tokens[2], tokens[3:])
+
+register.tag('cache', do_cache)
diff --git a/django/utils/checksums.py b/django/utils/checksums.py
new file mode 100644
index 0000000000..970f563f38
--- /dev/null
+++ b/django/utils/checksums.py
@@ -0,0 +1,22 @@
+"""
+Common checksum routines (used in multiple localflavor/ cases, for example).
+"""
+
+__all__ = ['luhn',]
+
+LUHN_ODD_LOOKUP = (0, 2, 4, 6, 8, 1, 3, 5, 7, 9) # sum_of_digits(index * 2)
+
+def luhn(candidate):
+    """
+    Checks a candidate number for validity according to the Luhn
+    algorithm (used in validation of, for example, credit cards).
+    Both numeric and string candidates are accepted.
+    """
+    if not isinstance(candidate, basestring):
+        candidate = str(candidate)
+    try:
+        evens = sum([int(c) for c in candidate[-1::-2]])
+        odds = sum([LUHN_ODD_LOOKUP[int(c)] for c in candidate[-2::-2]])
+        return ((evens + odds) % 10 == 0)
+    except ValueError:  # Raised if an int conversion fails
+        return False