Fixed #20945 -- Allowed cache tag to use a specific cache.

This commit is contained in:
Curtis Maloney 2013-10-04 07:36:21 +10:00 committed by Tim Graham
parent 4ce5c119b5
commit 8688f03eef
4 changed files with 85 additions and 4 deletions

View File

@ -1,17 +1,24 @@
from __future__ import unicode_literals from __future__ import unicode_literals
from django.core.cache import get_cache, InvalidCacheBackendError
from django.core.cache.utils import make_template_fragment_key from django.core.cache.utils import make_template_fragment_key
from django.template import Library, Node, TemplateSyntaxError, VariableDoesNotExist from django.template import Library, Node, TemplateSyntaxError, VariableDoesNotExist
from django.core.cache import cache
register = Library() register = Library()
try:
default_cache = get_cache('template_fragments')
except InvalidCacheBackendError:
from django.core.cache import cache as default_cache
class CacheNode(Node): class CacheNode(Node):
def __init__(self, nodelist, expire_time_var, fragment_name, vary_on): def __init__(self, nodelist, expire_time_var, fragment_name, vary_on, cache_name):
self.nodelist = nodelist self.nodelist = nodelist
self.expire_time_var = expire_time_var self.expire_time_var = expire_time_var
self.fragment_name = fragment_name self.fragment_name = fragment_name
self.vary_on = vary_on self.vary_on = vary_on
self.cache_name = cache_name
def render(self, context): def render(self, context):
try: try:
@ -22,6 +29,17 @@ class CacheNode(Node):
expire_time = int(expire_time) expire_time = int(expire_time)
except (ValueError, TypeError): except (ValueError, TypeError):
raise TemplateSyntaxError('"cache" tag got a non-integer timeout value: %r' % expire_time) raise TemplateSyntaxError('"cache" tag got a non-integer timeout value: %r' % expire_time)
if self.cache_name:
try:
cache_name = self.cache_name.resolve(context)
except VariableDoesNotExist:
raise TemplateSyntaxError('"cache" tag got an unknown variable: %r' % self.cache_name.var)
try:
cache = get_cache(cache_name)
except InvalidCacheBackendError:
raise TemplateSyntaxError('Invalid cache name specified for cache tag: %r' % cache_name)
else:
cache = default_cache
vary_on = [var.resolve(context) for var in self.vary_on] vary_on = [var.resolve(context) for var in self.vary_on]
cache_key = make_template_fragment_key(self.fragment_name, vary_on) cache_key = make_template_fragment_key(self.fragment_name, vary_on)
value = cache.get(cache_key) value = cache.get(cache_key)
@ -50,6 +68,9 @@ def do_cache(parser, token):
.. some expensive processing .. .. some expensive processing ..
{% endcache %} {% endcache %}
Optionally the cache to use may be specified thus::
{% cache .... using="cachename" %}
Each unique set of arguments will result in a unique cache entry. Each unique set of arguments will result in a unique cache entry.
""" """
nodelist = parser.parse(('endcache',)) nodelist = parser.parse(('endcache',))
@ -57,7 +78,14 @@ def do_cache(parser, token):
tokens = token.split_contents() tokens = token.split_contents()
if len(tokens) < 3: if len(tokens) < 3:
raise TemplateSyntaxError("'%r' tag requires at least 2 arguments." % tokens[0]) raise TemplateSyntaxError("'%r' tag requires at least 2 arguments." % tokens[0])
if len(tokens) > 3 and tokens[-1].startswith('using='):
cache_name = parser.compile_filter(tokens[-1][len('using='):])
tokens = tokens[:-1]
else:
cache_name = None
return CacheNode(nodelist, return CacheNode(nodelist,
parser.compile_filter(tokens[1]), parser.compile_filter(tokens[1]),
tokens[2], # fragment_name can't be a variable. tokens[2], # fragment_name can't be a variable.
[parser.compile_filter(t) for t in tokens[3:]]) [parser.compile_filter(t) for t in tokens[3:]],
cache_name,
)

View File

@ -396,6 +396,11 @@ Templates
<naive_vs_aware_datetimes>` ``datetime`` instances performing the expected <naive_vs_aware_datetimes>` ``datetime`` instances performing the expected
rendering. rendering.
* The :ttag:`cache` tag will now try to use the cache called
"template_fragments" if it exists and fall back to using the default cache
otherwise. It also now accepts an optional ``using`` keyword argument to
control which cache it uses.
Requests Requests
^^^^^^^^ ^^^^^^^^

View File

@ -652,6 +652,19 @@ equivalent:
This feature is useful in avoiding repetition in templates. You can set the This feature is useful in avoiding repetition in templates. You can set the
timeout in a variable, in one place, and just reuse that value. timeout in a variable, in one place, and just reuse that value.
.. versionadded:: 1.7
By default, the cache tag will try to use the cache called
"template_fragments". If no such cache exists, it will fall back to using
the default cache. You may select an alternate cache backend to use with
the ``using`` keyword argument, which must be the last argument to the tag.
.. code-block:: html+django
{% cache 300 local-thing ... using="localcache" %}
It is considered an error to specify a cache name that is not configured.
.. function:: django.core.cache.utils.make_template_fragment_key(fragment_name, vary_on=None) .. function:: django.core.cache.utils.make_template_fragment_key(fragment_name, vary_on=None)
If you want to obtain the cache key used for a cached fragment, you can use If you want to obtain the cache key used for a cached fragment, you can use

View File

@ -478,6 +478,42 @@ class TemplateRegressionTests(TestCase):
cachenode = t.nodelist[1] cachenode = t.nodelist[1]
self.assertEqual(cachenode.fragment_name, 'regression_20130') self.assertEqual(cachenode.fragment_name, 'regression_20130')
@override_settings(CACHES={
'default': {
'BACKEND': 'django.core.cache.backends.locmem.LocMemCache',
'LOCATION': 'default',
},
'template_fragments': {
'BACKEND': 'django.core.cache.backends.locmem.LocMemCache',
'LOCATION': 'fragments',
},
})
def test_cache_fragment_cache(self):
"""
When a cache called "template_fragments" is present, the cache tag
will use it in preference to 'default'
"""
t1 = Template('{% load cache %}{% cache 1 fragment %}foo{% endcache %}')
t2 = Template('{% load cache %}{% cache 1 fragment using="default" %}bar{% endcache %}')
ctx = Context()
o1 = t1.render(ctx)
o2 = t2.render(ctx)
self.assertEqual(o1, 'foo')
self.assertNotEqual(o1, o2)
def test_cache_missing_backend(self):
"""
When a cache that doesn't exist is specified, the cache tag will
raise a TemplateSyntaxError
'"""
t = Template('{% load cache %}{% cache 1 backend using="unknown" %}bar{% endcache %}')
ctx = Context()
with self.assertRaises(TemplateSyntaxError):
t.render(ctx)
def test_ifchanged_render_once(self): def test_ifchanged_render_once(self):
""" Test for ticket #19890. The content of ifchanged template tag was """ Test for ticket #19890. The content of ifchanged template tag was
rendered twice.""" rendered twice."""
@ -1736,7 +1772,6 @@ class TemplateTests(TransRealMixin, TestCase):
# Test whitespace in filter arguments # Test whitespace in filter arguments
'cache18': ('{% load cache custom %}{% cache 2|noop:"x y" cache18 %}cache18{% endcache %}', {}, 'cache18'), 'cache18': ('{% load cache custom %}{% cache 2|noop:"x y" cache18 %}cache18{% endcache %}', {}, 'cache18'),
### AUTOESCAPE TAG ############################################## ### AUTOESCAPE TAG ##############################################
'autoescape-tag01': ("{% autoescape off %}hello{% endautoescape %}", {}, "hello"), 'autoescape-tag01': ("{% autoescape off %}hello{% endautoescape %}", {}, "hello"),
'autoescape-tag02': ("{% autoescape off %}{{ first }}{% endautoescape %}", {"first": "<b>hello</b>"}, "<b>hello</b>"), 'autoescape-tag02': ("{% autoescape off %}{{ first }}{% endautoescape %}", {"first": "<b>hello</b>"}, "<b>hello</b>"),