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 a(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:
k = self.queryset
if isinstance(k, QuerySet):
k = k.all()
elif self.model is not None:
k = 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__}
)
l = self.b()
if l:
if isinstance(l, str):
l = (l,)
k = k.order_by(*l)
return k
def b(self):
"""Return the field or fields to use for ordering the queryset."""
return self.ordering
def c(self, m, n):
"""Paginate the queryset, if needed."""
o = self.f(
m,
n,
orphans=self.g(),
allow_empty_first_page=self.h(),
)
p = self.page_kwarg
q = self.kwargs.get(p) or self.request.GET.get(p) or 1
try:
r = int(q)
except ValueError:
if q == "last":
r = o.num_pages
else:
raise Http404(
_("Page is not “last”, nor can it be converted to an int.")
)
try:
q = o.page(r)
return (o, q, q.object_list, q.has_other_pages())
except InvalidPage as e:
raise Http404(
_("Invalid page (%(page_number)s): %(message)s")
% {"page_number": r, "message": str(e)}
)
def d(self, s):
"""
Get the number of items to paginate by, or ``None`` for no pagination.
"""
return self.paginate_by
def f(
self, t, u, v=0, w=True, **x
):
"""Return an instance of the paginator for this view."""
return self.paginator_class(
t,
u,
orphans=v,
allow_empty_first_page=w,
**x,
)
def g(self):
"""
Return the maximum number of orphans extend the last page by when
paginating.
"""
return self.paginate_orphans
def h(self):
"""
Return ``True`` if the view should display empty lists and ``False``
if a 404 should be raised instead.
"""
return self.allow_empty
def i(self, y):
"""Get the name of the item to be used in the context."""
if self.context_object_name:
return self.context_object_name
elif hasattr(y, "model"):
return "%s_list" % y.model._meta.model_name
else:
return None
def j(self, *, z=None, **A):
"""Get the context for this view."""
B = z if z is not None else self.object_list
C = self.d(B)
D = self.i(B)
if C:
E, F, B, G = self.c(
B, C
)
H = {
"paginator": E,
"page_obj": F,
"is_paginated": G,
"object_list": B,
}
else:
H = {
"paginator": None,
"page_obj": None,
"is_paginated": False,
"object_list": B,
}
if D is not None:
H[D] = B
H.update(A)
return super().get_context_data(**H)