Single object mixins

SingleObjectMixin

class django.views.generic.detail.SingleObjectMixin

Provides a mechanism for looking up an object associated with the current HTTP request.

Methods and Attributes

model

The model that this view will display data for. Specifying model = Foo is effectively the same as specifying queryset = Foo.objects.all(), where objects stands for Foo’s default manager.

queryset

A QuerySet that represents the objects. If provided, the value of queryset supersedes the value provided for model.

Warning

queryset is a class attribute with a mutable value so care must be taken when using it directly. Before using it, either call its all() method or retrieve it with get_queryset() which takes care of the cloning behind the scenes.

slug_field

The name of the field on the model that contains the slug. By default, slug_field is 'slug'.

slug_url_kwarg

The name of the URLConf keyword argument that contains the slug. By default, slug_url_kwarg is 'slug'.

pk_url_kwarg

The name of the URLConf keyword argument that contains the primary key. By default, pk_url_kwarg is 'pk'.

context_object_name

Designates the name of the variable to use in the context.

query_pk_and_slug

If True, causes get_object() to perform its lookup using both the primary key and the slug. Defaults to False.

This attribute can help mitigate insecure direct object reference attacks. When applications allow access to individual objects by a sequential primary key, an attacker could brute-force guess all URLs; thereby obtaining a list of all objects in the application. If users with access to individual objects should be prevented from obtaining this list, setting query_pk_and_slug to True will help prevent the guessing of URLs as each URL will require two correct, non-sequential arguments. Using a unique slug may serve the same purpose, but this scheme allows you to have non-unique slugs.

get_object(queryset=None)

Returns the single object that this view will display. If queryset is provided, that queryset will be used as the source of objects; otherwise, get_queryset() will be used. get_object() looks for a pk_url_kwarg argument in the arguments to the view; if this argument is found, this method performs a primary-key based lookup using that value. If this argument is not found, it looks for a slug_url_kwarg argument, and performs a slug lookup using the slug_field.

When query_pk_and_slug is True, get_object() will perform its lookup using both the primary key and the slug.

get_queryset()

Returns the queryset that will be used to retrieve the object that this view will display. By default, get_queryset() returns the value of the queryset attribute if it is set, otherwise it constructs a QuerySet by calling the all() method on the model attribute’s default manager.

get_context_object_name(obj)

Return the context variable name that will be used to contain the data that this view is manipulating. If context_object_name is not set, the context name will be constructed from the model_name of the model that the queryset is composed from. For example, the model Article would have context object named 'article'.

get_context_data(**kwargs)

Returns context data for displaying the object.

The base implementation of this method requires that the self.object attribute be set by the view (even if None). Be sure to do this if you are using this mixin without one of the built-in views that does so.

It returns a dictionary with these contents:

  • object: The object that this view is displaying (self.object).
  • context_object_name: self.object will also be stored under the name returned by get_context_object_name(), which defaults to the lowercased version of the model name.

Context variables override values from template context processors

Any variables from get_context_data() take precedence over context variables from context processors. For example, if your view sets the model attribute to User, the default context object name of user would override the user variable from the django.contrib.auth.context_processors.auth() context processor. Use get_context_object_name() to avoid a clash.

get_slug_field()

Returns the name of a slug field to be used to look up by slug. By default this returns the value of slug_field.

SingleObjectTemplateResponseMixin

class django.views.generic.detail.SingleObjectTemplateResponseMixin

A mixin class that performs template-based response rendering for views that operate upon a single object instance. Requires that the view it is mixed with provides self.object, the object instance that the view is operating on. self.object will usually be, but is not required to be, an instance of a Django model. It may be None if the view is in the process of constructing a new instance.

Extends

Methods and Attributes

template_name_field

The field on the current object instance that can be used to determine the name of a candidate template. If either template_name_field itself or the value of the template_name_field on the current object instance is None, the object will not be used for a candidate template name.

template_name_suffix

The suffix to append to the auto-generated candidate template name. Default suffix is _detail.

get_template_names()

Returns a list of candidate template names. 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>/<model_name><template_name_suffix>.html

© Django Software Foundation and individual contributors
Licensed under the BSD License.
https://docs.djangoproject.com/en/3.0/ref/class-based-views/mixins-single-object/