X-Git-Url: http://git.ithinksw.org/philo.git/blobdiff_plain/0d51e8dc2b15ca84b8979b94a3224b4a33f7f25e..55e5921bba41d37bef0a492badeca149796a54b9:/utils.py?ds=sidebyside

diff --git a/utils.py b/utils.py
index e3d1124..deb009c 100644
--- a/utils.py
+++ b/utils.py
@@ -1,6 +1,150 @@
+from django.db import models
+from django.contrib.contenttypes.models import ContentType
+from django.core.paginator import Paginator, EmptyPage
+from django.template import Context
+from django.template.loader_tags import ExtendsNode, ConstantIncludeNode
+
+
+class ContentTypeLimiter(object):
+	def q_object(self):
+		return models.Q(pk__in=[])
+	
+	def add_to_query(self, query, *args, **kwargs):
+		query.add_q(self.q_object(), *args, **kwargs)
+
+
+class ContentTypeRegistryLimiter(ContentTypeLimiter):
+	def __init__(self):
+		self.classes = []
+	
+	def register_class(self, cls):
+		self.classes.append(cls)
+	
+	def unregister_class(self, cls):
+		self.classes.remove(cls)
+	
+	def q_object(self):
+		contenttype_pks = []
+		for cls in self.classes:
+			try:
+				if issubclass(cls, models.Model):
+					if not cls._meta.abstract:
+						contenttype = ContentType.objects.get_for_model(cls)
+						contenttype_pks.append(contenttype.pk)
+			except:
+				pass
+		return models.Q(pk__in=contenttype_pks)
+
+
+class ContentTypeSubclassLimiter(ContentTypeLimiter):
+	def __init__(self, cls, inclusive=False):
+		self.cls = cls
+		self.inclusive = inclusive
+	
+	def q_object(self):
+		contenttype_pks = []
+		def handle_subclasses(cls):
+			for subclass in cls.__subclasses__():
+				try:
+					if issubclass(subclass, models.Model):
+						if not subclass._meta.abstract:
+							if not self.inclusive and subclass is self.cls:
+								continue
+							contenttype = ContentType.objects.get_for_model(subclass)
+							contenttype_pks.append(contenttype.pk)
+					handle_subclasses(subclass)
+				except:
+					pass
+		handle_subclasses(self.cls)
+		return models.Q(pk__in=contenttype_pks)
+
+
 def fattr(*args, **kwargs):
 	def wrapper(function):
 		for key in kwargs:
 			setattr(function, key, kwargs[key])
 		return function
 	return wrapper
+
+
+def paginate(objects, per_page=None, page_number=1):
+	"""
+	Given a list of objects, return a (paginator, page, objects) tuple.
+	"""
+	try:
+		per_page = int(per_page)
+	except (TypeError, ValueError):
+		# Then either it wasn't set or it was set to an invalid value
+		paginator = page = None
+	else:
+		# There also shouldn't be pagination if the list is too short. Try count()
+		# first - good chance it's a queryset, where count is more efficient.
+		try:
+			if objects.count() <= per_page:
+				paginator = page = None
+		except AttributeError:
+			if len(objects) <= per_page:
+				paginator = page = None
+	
+	try:
+		return paginator, page, objects
+	except NameError:
+		pass
+	
+	paginator = Paginator(objects, per_page)
+	try:
+		page_number = int(page_number)
+	except:
+		page_number = 1
+	
+	try:
+		page = paginator.page(page_number)
+	except EmptyPage:
+		page = None
+	else:
+		objects = page.object_list
+	
+	return paginator, page, objects
+
+
+LOADED_TEMPLATE_ATTR = '_philo_loaded_template'
+BLANK_CONTEXT = Context()
+
+
+def get_extended(self):
+	return self.get_parent(BLANK_CONTEXT)
+
+
+def get_included(self):
+	return self.template
+
+
+# We ignore the IncludeNode because it will never work in a blank context.
+setattr(ExtendsNode, LOADED_TEMPLATE_ATTR, property(get_extended))
+setattr(ConstantIncludeNode, LOADED_TEMPLATE_ATTR, property(get_included))
+
+
+def nodelist_crawl(nodelist, callback):
+	"""This function crawls through a template's nodelist and the nodelists of any included or extended
+	templates, as determined by the presence and value of <LOADED_TEMPLATE_ATTR> on a node. Each node
+	will also be passed to a callback function for additional processing."""
+	results = []
+	for node in nodelist:
+		try:
+			if hasattr(node, 'child_nodelists'):
+				for nodelist_name in node.child_nodelists:
+					if hasattr(node, nodelist_name):
+						results.extend(nodelist_crawl(getattr(node, nodelist_name), callback))
+			
+			# LOADED_TEMPLATE_ATTR contains the name of an attribute philo uses to declare a
+			# node as rendering an additional template. Philo monkeypatches the attribute onto
+			# the relevant default nodes and declares it on any native nodes.
+			if hasattr(node, LOADED_TEMPLATE_ATTR):
+				loaded_template = getattr(node, LOADED_TEMPLATE_ATTR)
+				if loaded_template:
+					results.extend(nodelist_crawl(loaded_template.nodelist, callback))
+			
+			callback(node, results)
+		except:
+			raise # fail for this node
+	return results
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