from django.core.exceptions import ValidationError
from django.core.urlresolvers import NoReverseMatch
from django.db import models
-from philo.models import TreeEntity, JSONField, Node
+from philo.models import TreeEntity, JSONField, Node, TreeManager
from philo.validators import RedirectValidator
#from mptt.templatetags.mptt_tags import cache_tree_children
DEFAULT_NAVIGATION_DEPTH = 3
-class NavigationManager(models.Manager):
+class NavigationManager(TreeManager):
# Analagous to contenttypes, cache Navigation to avoid repeated lookups all over the place.
# Navigation will probably be used frequently.
TODO: Should this create the auto-generated navigation in "physical" form?
"""
- key = node.pk
try:
- hosted_navigation = self.__class__._cache[self.db][key]
+ return self._get_from_cache(self.db, node)
except KeyError:
# Find the most recent host!
ancestors = node.get_ancestors(ascending=True, include_self=True).annotate(num_navigation=models.Count("hosted_navigation"))
# Iterate down the ancestors until you find one that:
# a) is cached, or
# b) has hosted navigation.
- pks_to_cache = []
+ nodes_to_cache = []
host_node = None
for ancestor in ancestors:
- if ancestor.pk in self.__class__._cache[self.db] or ancestor.num_navigation > 0:
+ if self._is_cached(self.db, ancestor) or ancestor.num_navigation > 0:
host_node = ancestor
break
else:
- pks_to_cache.append(ancestor.pk)
-
- if host_node is None:
- return self.none()
-
- if ancestor.pk not in self.__class__._cache[self.db]:
- self.__class__._cache[self.db][ancestor.pk] = host_node.hosted_navigation.select_related('target_node')
+ nodes_to_cache.append(ancestor)
- hosted_navigation = self.__class__._cache[self.db][ancestor.pk]
+ if not self._is_cached(self.db, host_node):
+ self._add_to_cache(self.db, host_node)
- # Cache the queryset instance for every pk that was passed over, as well.
- for pk in pks_to_cache:
- self.__class__._cache[self.db][pk] = hosted_navigation
+ # Cache the queryset instance for every node that was passed over, as well.
+ hosted_navigation = self._get_from_cache(self.db, host_node)
+ for node in nodes_to_cache:
+ self._add_to_cache(self.db, node, hosted_navigation)
return hosted_navigation
+ def _add_to_cache(self, using, node, qs=None):
+ if node is None or node.pk is None:
+ qs = self.none()
+ key = None
+ else:
+ key = node.pk
+
+ if qs is None:
+ qs = node.hosted_navigation.select_related('target_node')
+
+ self.__class__._cache.setdefault(using, {})[key] = qs
+
+ def _get_from_cache(self, using, node):
+ key = node.pk
+ return self.__class__._cache[self.db][key]
+
+ def _is_cached(self, using, node):
+ try:
+ self._get_from_cache(using, node)
+ except KeyError:
+ return False
+ return True
+
def clear_cache(self, navigation=None):
"""
Clear out the navigation cache. This needs to happen during database flushes
class Navigation(TreeEntity):
+ objects = NavigationManager()
text = models.CharField(max_length=50)
hosting_node = models.ForeignKey(Node, blank=True, null=True, related_name='hosted_navigation', help_text="Be part of this node's root navigation.")