django1/django/views/generic/detail.py

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from __future__ import unicode_literals
from django.core.exceptions import ImproperlyConfigured
from django.db import models
from django.http import Http404
from django.utils.translation import ugettext as _
from django.views.generic.base import TemplateResponseMixin, ContextMixin, View
class SingleObjectMixin(ContextMixin):
"""
Provides the ability to retrieve a single object for further manipulation.
"""
model = None
queryset = None
slug_field = 'slug'
context_object_name = None
slug_url_kwarg = 'slug'
pk_url_kwarg = 'pk'
def get_object(self, queryset=None):
"""
Returns the object the view is displaying.
By default this requires `self.queryset` and a `pk` or `slug` argument
in the URLconf, but subclasses can override this to return any object.
"""
# Use a custom queryset if provided; this is required for subclasses
# like DateDetailView
if queryset is None:
queryset = self.get_queryset()
# Next, try looking up by primary key.
pk = self.kwargs.get(self.pk_url_kwarg, None)
slug = self.kwargs.get(self.slug_url_kwarg, None)
if pk is not None:
queryset = queryset.filter(pk=pk)
# Next, try looking up by slug.
elif slug is not None:
slug_field = self.get_slug_field()
queryset = queryset.filter(**{slug_field: slug})
# If none of those are defined, it's an error.
else:
raise AttributeError("Generic detail view %s must be called with "
"either an object pk or a slug."
% self.__class__.__name__)
try:
# Get the single item from the filtered queryset
obj = queryset.get()
except queryset.model.DoesNotExist:
raise Http404(_("No %(verbose_name)s found matching the query") %
{'verbose_name': queryset.model._meta.verbose_name})
return obj
def get_queryset(self):
"""
Return the `QuerySet` that will be used to look up the object.
Note that this method is called by the default implementation of
`get_object` and may not be called if `get_object` is overriden.
"""
if self.queryset is None:
if self.model:
return 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__
}
)
return self.queryset.all()
def get_slug_field(self):
"""
Get the name of a slug field to be used to look up by slug.
"""
return self.slug_field
def get_context_object_name(self, obj):
"""
Get the name to use for the object.
"""
if self.context_object_name:
return self.context_object_name
elif isinstance(obj, models.Model):
return obj._meta.model_name
else:
return None
def get_context_data(self, **kwargs):
"""
Insert the single object into the context dict.
"""
context = {}
if self.object:
context['object'] = self.object
context_object_name = self.get_context_object_name(self.object)
if context_object_name:
context[context_object_name] = self.object
context.update(kwargs)
return super(SingleObjectMixin, self).get_context_data(**context)
class BaseDetailView(SingleObjectMixin, View):
"""
A base view for displaying a single object
"""
def get(self, request, *args, **kwargs):
self.object = self.get_object()
context = self.get_context_data(object=self.object)
return self.render_to_response(context)
class SingleObjectTemplateResponseMixin(TemplateResponseMixin):
template_name_field = None
template_name_suffix = '_detail'
def get_template_names(self):
"""
Return a list of template names to be used for the request. May not be
called if render_to_response is overridden. Returns the following list:
* the value of ``template_name`` on the view (if provided)
* the contents of the ``template_name_field`` field on the
object instance that the view is operating upon (if available)
* ``<app_label>/<object_name><template_name_suffix>.html``
"""
try:
names = super(SingleObjectTemplateResponseMixin, self).get_template_names()
except ImproperlyConfigured:
# If template_name isn't specified, it's not a problem --
# we just start with an empty list.
names = []
# If self.template_name_field is set, grab the value of the field
# of that name from the object; this is the most specific template
# name, if given.
if self.object and self.template_name_field:
name = getattr(self.object, self.template_name_field, None)
if name:
names.insert(0, name)
# The least-specific option is the default <app>/<model>_detail.html;
# only use this if the object in question is a model.
if isinstance(self.object, models.Model):
names.append("%s/%s%s.html" % (
self.object._meta.app_label,
self.object._meta.model_name,
self.template_name_suffix
))
elif hasattr(self, 'model') and self.model is not None and issubclass(self.model, models.Model):
names.append("%s/%s%s.html" % (
self.model._meta.app_label,
self.model._meta.model_name,
self.template_name_suffix
))
# If we still haven't managed to find any template names, we should
# re-raise the ImproperlyConfigured to alert the user.
if not names:
raise
return names
class DetailView(SingleObjectTemplateResponseMixin, BaseDetailView):
"""
Render a "detail" view of an object.
By default this is a model instance looked up from `self.queryset`, but the
view will support display of *any* object by overriding `self.get_object()`.
"""