+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
\ No newline at end of file