From 52d3a0f1ca43820d59447c256126aaba7a726dcd Mon Sep 17 00:00:00 2001
From: Stephen Burrows <stephen.r.burrows@gmail.com>
Date: Fri, 24 Jun 2011 10:18:19 -0400
Subject: [PATCH] Corrections to has_navigation and navigation_host to use the
 new NavigationMapper correctly. Also added select_related calls to the
 NavigationManager.get_for_node method.

---
 philo/contrib/shipherd/models.py               | 18 ++++++++++++------
 .../contrib/shipherd/templatetags/shipherd.py  | 10 ++--------
 2 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/philo/contrib/shipherd/models.py b/philo/contrib/shipherd/models.py
index c8579a2..9888378 100644
--- a/philo/contrib/shipherd/models.py
+++ b/philo/contrib/shipherd/models.py
@@ -21,9 +21,15 @@ class NavigationMapper(object, DictMixin):
 	"""
 	def __init__(self, node):
 		self.node = node
+		self._cache = {}
 	
 	def __getitem__(self, key):
-		return Navigation.objects.get_for_node(self.node, key)
+		if key not in self._cache:
+			try:
+				self._cache[key] = Navigation.objects.get_for_node(self.node, key)
+			except Navigation.DoesNotExist:
+				self._cache[key] = None
+		return self._cache[key]
 
 
 def navigation(self):
@@ -42,21 +48,21 @@ class NavigationManager(models.Manager):
 		opts = Node._mptt_meta
 		left = getattr(node, opts.left_attr)
 		right = getattr(node, opts.right_attr)
-		tree = getattr(node, opts.tree_id_attr)
+		tree_id = getattr(node, opts.tree_id_attr)
 		kwargs = {
 			"node__%s__lte" % opts.left_attr: left,
 			"node__%s__gte" % opts.right_attr: right,
 			"node__%s" % opts.tree_id_attr: tree_id
 		}
-		navs = self.filter(key=key, **kwargs).order_by('-node__%s' % opts.level_attr)
+		navs = self.filter(key=key, **kwargs).select_related('node').order_by('-node__%s' % opts.level_attr)
 		nav = navs[0]
-		roots = nav.roots.all()
+		roots = nav.roots.all().select_related('target_node')
 		item_opts = NavigationItem._mptt_meta
 		by_pk = {}
 		tree_ids = []
 		
 		for root in roots:
-			by_pk[root.pk] = pk
+			by_pk[root.pk] = root
 			tree_ids.append(getattr(root, item_opts.tree_id_attr))
 			root._cached_children = []
 		
@@ -65,7 +71,7 @@ class NavigationManager(models.Manager):
 			'%s__lt' % item_opts.level_attr: nav.depth,
 			'%s__gt' % item_opts.level_attr: 0
 		}
-		items = NavigationItem.objects.filter(**kwargs).order_by('level', 'order')
+		items = NavigationItem.objects.filter(**kwargs).select_related('target_node').order_by('level', 'order')
 		for item in items:
 			by_pk[item.pk] = item
 			item._cached_children = []
diff --git a/philo/contrib/shipherd/templatetags/shipherd.py b/philo/contrib/shipherd/templatetags/shipherd.py
index 1031d73..833a995 100644
--- a/philo/contrib/shipherd/templatetags/shipherd.py
+++ b/philo/contrib/shipherd/templatetags/shipherd.py
@@ -173,13 +173,7 @@ def recursenavigation(parser, token):
 def has_navigation(node, key=None):
 	"""Returns ``True`` if the node has a :class:`.Navigation` with the given key and ``False`` otherwise. If ``key`` is ``None``, returns whether the node has any :class:`.Navigation`\ s at all."""
 	try:
-		nav = node.navigation
-		if key is not None:
-			if key in nav and bool(node.navigation[key]):
-				return True
-			elif key not in node.navigation:
-				return False
-		return bool(node.navigation)
+		return bool(node.navigation[key])
 	except:
 		return False
 
@@ -188,6 +182,6 @@ def has_navigation(node, key=None):
 def navigation_host(node, key):
 	"""Returns the :class:`.Node` which hosts the :class:`.Navigation` which ``node`` has inherited for ``key``. Returns ``node`` if any exceptions are encountered."""
 	try:
-		return Navigation.objects.filter(node__in=node.get_ancestors(include_self=True), key=key).order_by('-node__level')[0].node
+		return node.navigation[key].node
 	except:
 		return node
\ No newline at end of file
-- 
2.20.1