def get_value(self, context, *tag_args, **tag_kwargs):
request = self.get_request(context)
output = None
# Process arguments
(slot,) = tag_args
template_name = tag_kwargs.get('template') or None
cachable = is_true(tag_kwargs.get('cachable', not bool(template_name))) # default: True unless there is a template.
if template_name and cachable and not extract_literal(self.kwargs['template']):
# If the template name originates from a variable, it can change any time.
# See PagePlaceholderNode.render_tag() why this is not allowed.
raise TemplateSyntaxError("{0} tag does not allow 'cachable' for variable template names!".format(self.tag_name))
# Caching will not happen when rendering via a template,
# because there is no way to tell whether that can be expired/invalidated.
try_cache = appsettings.FLUENT_CONTENTS_CACHE_OUTPUT \
and appsettings.FLUENT_CONTENTS_CACHE_PLACEHOLDER_OUTPUT \
and cachable
if isinstance(slot, SharedContent):
# Allow passing a sharedcontent, just like 'render_placeholder' does.
sharedcontent = slot
# See if there is cached output, avoid fetching the Placeholder via sharedcontents.contents.
if try_cache:
cache_key = get_shared_content_cache_key(sharedcontent)
output = cache.get(cache_key)
else:
site = Site.objects.get_current()
if try_cache:
# See if there is output cached, try to avoid fetching the SharedContent + Placeholder model.
# Have to perform 2 cache calls for this, because the placeholder output key is based on object IDs
cache_key_ptr = get_shared_content_cache_key_ptr(int(site.pk), slot, language_code=get_language())
cache_key = cache.get(cache_key_ptr)
if cache_key is not None:
output = cache.get(cache_key)
if output is None:
# Get the placeholder
try:
sharedcontent = SharedContent.objects.parent_site(site).get(slug=slot)
except SharedContent.DoesNotExist:
return "<!-- shared content '{0}' does not yet exist -->".format(slot)
# Now that we've fetched the object, the object key be generated.
# No real need to check for output again, render_placeholder() does that already.
if try_cache and not cache_key:
cache.set(cache_key_ptr, get_shared_content_cache_key(sharedcontent))
if output is None:
# Have to fetch + render it.
output = self.render_shared_content(request, sharedcontent, template_name, cachable=cachable)
rendering.register_frontend_media(request, output.media) # Need to track frontend media here, as the template tag can't return it.
return output.html
def get_cache_keys(self):
# When the shared content is saved, make sure all rendering output PTRs are cleared.
# The 'slug' could have changed. Whether the Placeholder output is cleared,
# depends on whether those objects are altered too.
if self.is_cross_site or self._was_cross_site:
sites = list(Site.objects.all().values_list('pk', flat=True))
else:
sites = [self.parent_site_id]
keys = []
for site_id in sites:
for language_code, _ in settings.LANGUAGES:
keys.append(get_shared_content_cache_key_ptr(site_id, self._old_slug, language_code))
return keys
def get_cache_keys(self):
# When the shared content is saved, make sure all rendering output PTRs are cleared.
# The 'slug' could have changed. Whether the Placeholder output is cleared,
# depends on whether those objects are altered too.
if self.is_cross_site or self._was_cross_site:
sites = list(Site.objects.all().values_list('pk', flat=True))
else:
sites = [self.parent_site_id]
keys = []
for site_id in sites:
for language_code, _ in settings.LANGUAGES:
keys.append(get_shared_content_cache_key_ptr(site_id, self._old_slug, language_code))
return keys
