--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/templatetags/cache.py Fri Jul 18 18:22:23 2008 +0000
@@ -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)