+++ /dev/null
-#encoding: utf-8
-from django.core.exceptions import ValidationError
-from django.core.urlresolvers import NoReverseMatch
-from django.core.validators import RegexValidator, MinValueValidator
-from django.db import models
-from django.forms.models import model_to_dict
-from philo.models import TreeEntity, Node, TreeManager, Entity, TargetURLModel
-from philo.validators import RedirectValidator
-from UserDict import DictMixin
-
-
-DEFAULT_NAVIGATION_DEPTH = 3
-
-
-class NavigationQuerySetMapper(object, DictMixin):
- """This class exists to prevent setting of items in the navigation cache through node.navigation."""
- def __init__(self, node):
- self.node = node
-
- def __getitem__(self, key):
- return Navigation.objects.get_cache_for(self.node)[key]['root_items']
-
- def keys(self):
- return Navigation.objects.get_cache_for(self.node).keys()
-
-
-def navigation(self):
- if not hasattr(self, '_navigation'):
- self._navigation = NavigationQuerySetMapper(self)
- return self._navigation
-
-
-Node.navigation = property(navigation)
-
-
-class NavigationCacheQuerySet(models.query.QuerySet):
- """
- This subclass will trigger general cache clearing for Navigation.objects when a mass
- update or deletion is performed. As there is no convenient way to iterate over the
- changed or deleted instances, there's no way to be more precise about what gets cleared.
- """
- def update(self, *args, **kwargs):
- super(NavigationCacheQuerySet, self).update(*args, **kwargs)
- Navigation.objects.clear_cache()
-
- def delete(self, *args, **kwargs):
- super(NavigationCacheQuerySet, self).delete(*args, **kwargs)
- Navigation.objects.clear_cache()
-
-
-class NavigationManager(models.Manager):
- # Since navigation is going to be hit frequently and changed
- # relatively infrequently, cache it. Analogous to contenttypes.
- use_for_related = True
- _cache = {}
-
- def get_queryset(self):
- return NavigationCacheQuerySet(self.model, using=self._db)
-
- def get_cache_for(self, node, update_targets=True):
- created = False
- if not self.has_cache_for(node):
- self.create_cache_for(node)
- created = True
-
- if update_targets and not created:
- self.update_targets_for(node)
-
- return self.__class__._cache[self.db][node]
-
- def has_cache_for(self, node):
- return self.db in self.__class__._cache and node in self.__class__._cache[self.db]
-
- def create_cache_for(self, node):
- "This method loops through the nodes ancestors and caches all unique navigation keys."
- ancestors = node.get_ancestors(ascending=True, include_self=True)
-
- nodes_to_cache = []
-
- for node in ancestors:
- if self.has_cache_for(node):
- cache = self.get_cache_for(node).copy()
- break
- else:
- nodes_to_cache.insert(0, node)
- else:
- cache = {}
-
- for node in nodes_to_cache:
- cache = cache.copy()
- cache.update(self._build_cache_for(node))
- self.__class__._cache.setdefault(self.db, {})[node] = cache
-
- def _build_cache_for(self, node):
- cache = {}
- tree_id_attr = NavigationItem._mptt_meta.tree_id_attr
- level_attr = NavigationItem._mptt_meta.level_attr
-
- for navigation in node.navigation_set.all():
- tree_ids = navigation.roots.values_list(tree_id_attr)
- items = list(NavigationItem.objects.filter(**{'%s__in' % tree_id_attr: tree_ids, '%s__lt' % level_attr: navigation.depth}).order_by('order', 'lft'))
-
- root_items = []
-
- for item in items:
- item._is_cached = True
-
- if not hasattr(item, '_cached_children'):
- item._cached_children = []
-
- if item.parent:
- # alternatively, if I don't want to force it to a list, I could keep track of
- # instances where the parent hasn't yet been met and do this step later for them.
- # delayed action.
- item.parent = items[items.index(item.parent)]
- if not hasattr(item.parent, '_cached_children'):
- item.parent._cached_children = []
- item.parent._cached_children.append(item)
- else:
- root_items.append(item)
-
- cache[navigation.key] = {
- 'navigation': navigation,
- 'root_items': root_items,
- 'items': items
- }
-
- return cache
-
- def clear_cache_for(self, node):
- # Clear the cache for this node and all its descendants. The
- # navigation for this node has probably changed, and for now,
- # it isn't worth it to only clear the descendants actually
- # affected by this.
- if not self.has_cache_for(node):
- # Already cleared.
- return
-
- descendants = node.get_descendants(include_self=True)
- cache = self.__class__._cache[self.db]
- for node in descendants:
- cache.pop(node, None)
-
- def update_targets_for(self, node):
- # Manually update a cache's target nodes in case something's changed there.
- # This should be a less complex operation than reloading the models each
- # time. Not as good as selective updates... but not much to be done
- # about that. TODO: Benchmark it.
- caches = self.__class__._cache[self.db][node].values()
-
- target_pks = set()
-
- for cache in caches:
- target_pks |= set([item.target_node_id for item in cache['items']])
-
- # A distinct query is not strictly necessary. TODO: benchmark the efficiency
- # with/without distinct.
- targets = list(Node.objects.filter(pk__in=target_pks).distinct())
-
- for cache in caches:
- for item in cache['items']:
- if item.target_node_id:
- item.target_node = targets[targets.index(item.target_node)]
-
- def clear_cache(self):
- self.__class__._cache.pop(self.db, None)
-
-
-class Navigation(Entity):
- objects = NavigationManager()
-
- node = models.ForeignKey(Node, related_name='navigation_set', help_text="Be available as navigation for this node.")
- key = models.CharField(max_length=255, validators=[RegexValidator("\w+")], help_text="Must contain one or more alphanumeric characters or underscores.", db_index=True)
- depth = models.PositiveSmallIntegerField(default=DEFAULT_NAVIGATION_DEPTH, validators=[MinValueValidator(1)], help_text="Defines the maximum display depth of this navigation.")
-
- def __init__(self, *args, **kwargs):
- super(Navigation, self).__init__(*args, **kwargs)
- self._initial_data = model_to_dict(self)
-
- def __unicode__(self):
- return "%s[%s]" % (self.node, self.key)
-
- def _has_changed(self):
- return self._initial_data != model_to_dict(self)
-
- def save(self, *args, **kwargs):
- super(Navigation, self).save(*args, **kwargs)
-
- if self._has_changed():
- Navigation.objects.clear_cache_for(self.node)
- self._initial_data = model_to_dict(self)
-
- def delete(self, *args, **kwargs):
- super(Navigation, self).delete(*args, **kwargs)
- Navigation.objects.clear_cache_for(self.node)
-
- class Meta:
- unique_together = ('node', 'key')
-
-
-class NavigationItemManager(TreeManager):
- use_for_related = True
-
- def get_queryset(self):
- return NavigationCacheQuerySet(self.model, using=self._db)
-
-
-class NavigationItem(TreeEntity, TargetURLModel):
- objects = NavigationItemManager()
-
- navigation = models.ForeignKey(Navigation, blank=True, null=True, related_name='roots', help_text="Be a root in this navigation tree.")
- text = models.CharField(max_length=50)
-
- order = models.PositiveSmallIntegerField(default=0)
-
- def __init__(self, *args, **kwargs):
- super(NavigationItem, self).__init__(*args, **kwargs)
- self._initial_data = model_to_dict(self)
- self._is_cached = False
-
- def __unicode__(self):
- return self.get_path(field='text', pathsep=u' › ')
-
- def clean(self):
- super(NavigationItem, self).clean()
- if bool(self.parent) == bool(self.navigation):
- raise ValidationError("Exactly one of `parent` and `navigation` must be defined.")
-
- def is_active(self, request):
- if self.target_url == request.path:
- # Handle the `default` case where the target_url and requested path
- # are identical.
- return True
-
- if self.target_node is None and self.url_or_subpath == "http%s://%s%s" % (request.is_secure() and 's' or '', request.get_host(), request.path):
- # If there's no target_node, double-check whether it's a full-url
- # match.
- return True
-
- if self.target_node and not self.url_or_subpath:
- # If there is a target node and it's targeted simply, but the target URL is not
- # the same as the request path, check whether the target node is an ancestor
- # of the requested node. If so, this is active unless the target node
- # is the same as the ``host node`` for this navigation structure.
- try:
- host_node = self.get_root().navigation.node
- except AttributeError:
- pass
- else:
- if self.target_node != host_node and self.target_node.is_ancestor_of(request.node):
- return True
-
- return False
-
- def has_active_descendants(self, request):
- for child in self.get_children():
- if child.is_active(request) or child.has_active_descendants(request):
- return True
- return False
-
- def _has_changed(self):
- if model_to_dict(self) == self._initial_data:
- return False
- return True
-
- def _clear_cache(self):
- try:
- root = self.get_root()
- if self.get_level() < root.navigation.depth:
- Navigation.objects.clear_cache_for(self.get_root().navigation.node)
- except AttributeError:
- pass
-
- def save(self, *args, **kwargs):
- super(NavigationItem, self).save(*args, **kwargs)
-
- if self._has_changed():
- self._clear_cache()
-
- def delete(self, *args, **kwargs):
- super(NavigationItem, self).delete(*args, **kwargs)
- self._clear_cache()
\ No newline at end of file
git.ithinksw.org / philo.git / blobdiff