--- title: "Single object mixins" version: 4.0 locale: pl source: https://docs.djangoproject.com/pl/4.0/ref/class-based-views/mixins-single-object/ canonical: https://djangodocs.dev/pl/4.0/ref/class-based-views/mixins-single-object/ --- # 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](/pl/4.0/topics/db/managers/#default-managers). #### `queryset` A `QuerySet` that represents the objects. If provided, the value of `queryset` supersedes the value provided for [`model`](#django.views.generic.detail.SingleObjectMixin.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()`](/pl/4.0/ref/models/querysets/#django.db.models.query.QuerySet.all) method or > retrieve it with [`get_queryset()`](#django.views.generic.detail.SingleObjectMixin.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()`](#django.views.generic.detail.SingleObjectMixin.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](https://wiki.owasp.org/index.php/Top_10_2013-A4-Insecure_Direct_Object_References) 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()`](#django.views.generic.detail.SingleObjectMixin.get_queryset) will be used. `get_object()` looks for a [`pk_url_kwarg`](#django.views.generic.detail.SingleObjectMixin.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`](#django.views.generic.detail.SingleObjectMixin.slug_url_kwarg) argument, and performs a slug lookup using the [`slug_field`](#django.views.generic.detail.SingleObjectMixin.slug_field). When [`query_pk_and_slug`](#django.views.generic.detail.SingleObjectMixin.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()`](#django.views.generic.detail.SingleObjectMixin.get_queryset) returns the value of the [`queryset`](#django.views.generic.detail.SingleObjectMixin.queryset) attribute if it is set, otherwise it constructs a [`QuerySet`](/pl/4.0/ref/models/querysets/#django.db.models.query.QuerySet) by calling the `all()` method on the [`model`](#django.views.generic.detail.SingleObjectMixin.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`](#django.views.generic.detail.SingleObjectMixin.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()`](#django.views.generic.detail.SingleObjectMixin.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()`](#django.views.generic.detail.SingleObjectMixin.get_context_data) take precedence over > context variables from [context processors](/pl/4.0/ref/templates/api/#subclassing-context-requestcontext). For example, if your view > sets the [`model`](#django.views.generic.detail.SingleObjectMixin.model) attribute to > [`User`](/pl/4.0/ref/contrib/auth/#django.contrib.auth.models.User), the default context > object name of `user` would override the `user` variable from > the [`django.contrib.auth.context_processors.auth()`](/pl/4.0/ref/templates/api/#django.contrib.auth.context_processors.auth) context > processor. Use [`get_context_object_name()`](#django.views.generic.detail.SingleObjectMixin.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`](#django.views.generic.detail.SingleObjectMixin.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** - [`TemplateResponseMixin`](/pl/4.0/ref/class-based-views/mixins-simple/#django.views.generic.base.TemplateResponseMixin) **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) - `/.html`