def test_fragment_cache_miss(self):
# get the comment we want to invalidate the cache for
comment = Comment.objects.latest()
# cache the fragment
from django.template import Context, Template
template = Template("""
{% load cachesweeper_tags %}
{% cachesweeper comment 500 "comment.xml" %}
<p>
<strong>{{comment.user}}</strong> said at {{comment.created_at}}:<br/>
{{comment.content}}
<br/>
</p>
{% endcachesweeper %}
""")
template.render(Context({'comment': comment}))
# assert the cache hit
cache_key = generate_fragment_cache_key_for_record(comment, "comment.xml")
self.assertTrue(cache.get(cache_key))
# modifying the model should change the cache
comment.like_it()
# assert the changed cache key
new_cache_key = generate_fragment_cache_key_for_record(comment, "comment.xml")
self.assertNotEquals(cache_key, new_cache_key)
# assert the cache miss
self.assertFalse(cache.get(new_cache_key))
def render(self, context):
expire_time = self.get_expire_time(context)
model = self.get_model(context)
unique_fragment_cache_keys = [var.resolve(context)
for var in self.cache_key_vars]
cache_key = generate_fragment_cache_key_for_record(model, *unique_fragment_cache_keys)
value = cache.get(cache_key)
if value is None:
value = self.nodelist.render(context)
cache.set(cache_key, value, expire_time)
return value
