Source code
from django.core.exceptions import ImproperlyConfigured
from django.core.paginator import InvalidPage, Paginator
from django.db.models import QuerySet
from django.http import Http404
from django.utils.translation import gettext as _
from django.views.generic.base import ContextMixin, TemplateResponseMixin, View
class MultipleObjectMixin(ContextMixin):
"""A mixin for views manipulating multiple objects."""
allow_empty = True
queryset = None
model = None
paginate_by = None
paginate_orphans = 0
context_object_name = None
paginator_class = Paginator
page_kwarg = "page"
ordering = None
def get2(self):
"""
Return the list of items for this view.
The return value must be an iterable and may be an instance of
`QuerySet` in which case `QuerySet` specific behavior will be enabled.
"""
if self.queryset is not None:
que = self.queryset
if isinstance(que, QuerySet):
que = que.all()
elif self.model is not None:
que = self.model._default_manager.all()
else:
raise ImproperlyConfigured(
"%(cls)s is missing a QuerySet. Define "
"%(cls)s.model, %(cls)s.queryset, or override "
"%(cls)s.get_queryset()." % {"cls": self.__class__.__name__}
)
ord = self.get3()
if ord:
if isinstance(ord, str):
ord = (ord,)
que = que.order_by(*ord)
return que
def get3(self):
"""Return the field or fields to use for ordering the queryset."""
return self.ordering
def paginate(self, que2, page2):
"""Paginate the queryset, if needed."""
pag = self.get5(
que2,
page2,
orphans=self.get6(),
allow_empty_first_page=self.get7(),
)
page3 = self.page_kwarg
pag2 = self.kwargs.get(page3) or self.request.GET.get(page3) or 1
try:
page4 = int(pag2)
except ValueError:
if pag2 == "last":
page4 = pag.num_pages
else:
raise Http404(
_("Page is not “last”, nor can it be converted to an int.")
)
try:
pag2 = pag.page(page4)
return (pag, pag2, pag2.object_list, pag2.has_other_pages())
except InvalidPage as e:
raise Http404(
_("Invalid page (%(page_number)s): %(message)s")
% {"page_number": page4, "message": str(e)}
)
def get4(self, que3):
"""
Get the number of items to paginate by, or ``None`` for no pagination.
"""
return self.paginate_by
def get5(
self, que4, per, orp=0, allow=True, **kwa
):
"""Return an instance of the paginator for this view."""
return self.paginator_class(
que4,
per,
orphans=orp,
allow_empty_first_page=allow,
**kwa,
)
def get6(self):
"""
Return the maximum number of orphans extend the last page by when
paginating.
"""
return self.paginate_orphans
def get7(self):
"""
Return ``True`` if the view should display empty lists and ``False``
if a 404 should be raised instead.
"""
return self.allow_empty
def get8(self, object):
"""Get the name of the item to be used in the context."""
if self.context_object_name:
return self.context_object_name
elif hasattr(object, "model"):
return "%s_list" % object.model._meta.model_name
else:
return None
def get9(self, *, object2=None, **kwa2):
"""Get the context for this view."""
que5 = object2 if object2 is not None else self.object_list
page5 = self.get4(que5)
context2 = self.get8(que5)
if page5:
pag3, pag4, que5, is2 = self.paginate(
que5, page5
)
con = {
"paginator": pag3,
"page_obj": pag4,
"is_paginated": is2,
"object_list": que5,
}
else:
con = {
"paginator": None,
"page_obj": None,
"is_paginated": False,
"object_list": que5,
}
if context2 is not None:
con[context2] = que5
con.update(kwa2)
return super().get_context_data(**con)