django/docs/ref/contrib/admin/index.txt

=====================
The Django admin site
=====================

.. module:: django.contrib.admin
   :synopsis: Django's admin site.

One of the most powerful parts of Django is the automatic admin interface. It
reads metadata in your model to provide a powerful and production-ready
interface that content producers can immediately use to start adding content to
the site. In this document, we discuss how to activate, use and customize
Django's admin interface.

Overview
========

The admin is enabled in the default project template used by
:djadmin:`startproject`.

For reference, here are the requirements:

1. Add ``'django.contrib.admin'`` to your :setting:`INSTALLED_APPS` setting.

2. The admin has four dependencies - :mod:`django.contrib.auth`,
   :mod:`django.contrib.contenttypes`,
   :mod:`django.contrib.messages` and
   :mod:`django.contrib.sessions`.  If these applications are not
   in your :setting:`INSTALLED_APPS` list, add them.

3. Add ``django.contrib.messages.context_processors.messages`` to
   the ``'context_processors'`` option of the ``DjangoTemplates`` backend
   defined in your :setting:`TEMPLATES` as well as
   :class:`django.contrib.auth.middleware.AuthenticationMiddleware` and
   :class:`django.contrib.messages.middleware.MessageMiddleware` to
   :setting:`MIDDLEWARE_CLASSES`. (These are all active by default, so
   you only need to do this if you've manually tweaked the settings.)

4. Determine which of your application's models should be editable in the
   admin interface.

5. For each of those models, optionally create a ``ModelAdmin`` class that
   encapsulates the customized admin functionality and options for that
   particular model.

6. Instantiate an ``AdminSite`` and tell it about each of your models and
   ``ModelAdmin`` classes.

7. Hook the ``AdminSite`` instance into your URLconf.

After you've taken these steps, you'll be able to use your Django admin site
by visiting the URL you hooked it into (``/admin/``, by default).

Other topics
------------

.. toctree::
   :maxdepth: 1

   actions
   admindocs

.. seealso::

    For information about serving the static files (images, JavaScript, and
    CSS) associated with the admin in production, see :ref:`serving-files`.

    Having problems?  Try :doc:`/faq/admin`.

``ModelAdmin`` objects
======================

.. class:: ModelAdmin

    The ``ModelAdmin`` class is the representation of a model in the admin
    interface. Usually, these are stored in a file named ``admin.py`` in your
    application. Let's take a look at a very simple example of
    the ``ModelAdmin``::

        from django.contrib import admin
        from myproject.myapp.models import Author

        class AuthorAdmin(admin.ModelAdmin):
            pass
        admin.site.register(Author, AuthorAdmin)

    .. admonition:: Do you need a ``ModelAdmin`` object at all?

        In the preceding example, the ``ModelAdmin`` class doesn't define any
        custom values (yet). As a result, the default admin interface will be
        provided. If you are happy with the default admin interface, you don't
        need to define a ``ModelAdmin`` object at all -- you can register the
        model class without providing a ``ModelAdmin`` description. The
        preceding example could be simplified to::

            from django.contrib import admin
            from myproject.myapp.models import Author

            admin.site.register(Author)

The register decorator
----------------------

.. function:: register(*models, [site=django.admin.sites.site])

    There is also a decorator for registering your ``ModelAdmin`` classes::

        from django.contrib import admin
        from .models import Author

        @admin.register(Author)
        class AuthorAdmin(admin.ModelAdmin):
            pass

    It is given one or more model classes to register with the ``ModelAdmin``
    and an optional keyword argument ``site`` if you are not using the default
    ``AdminSite``::

        from django.contrib import admin
        from .models import Author, Reader, Editor
        from myproject.admin_site import custom_admin_site

        @admin.register(Author, Reader, Editor, site=custom_admin_site)
        class PersonAdmin(admin.ModelAdmin):
            pass

Discovery of admin files
------------------------

When you put ``'django.contrib.admin'`` in your :setting:`INSTALLED_APPS`
setting, Django automatically looks for an ``admin`` module in each
application and imports it.

.. class:: apps.AdminConfig

    This is the default :class:`~django.apps.AppConfig` class for the admin.
    It calls :func:`~django.contrib.admin.autodiscover()` when Django starts.

.. class:: apps.SimpleAdminConfig

    This class works like :class:`~django.contrib.admin.apps.AdminConfig`,
    except it doesn't call :func:`~django.contrib.admin.autodiscover()`.

.. function:: autodiscover

    This function attempts to import an ``admin`` module in each installed
    application. Such modules are expected to register models with the admin.

    Typically you won't need to call this function directly as
    :class:`~django.contrib.admin.apps.AdminConfig` calls it when Django starts.

If you are using a custom ``AdminSite``, it is common to import all of the
``ModelAdmin`` subclasses into your code and register them to the custom
``AdminSite``. In that case, in order to disable auto-discovery, you should
put ``'django.contrib.admin.apps.SimpleAdminConfig'`` instead of
``'django.contrib.admin'`` in your :setting:`INSTALLED_APPS` setting.

``ModelAdmin`` options
----------------------

The ``ModelAdmin`` is very flexible. It has several options for dealing with
customizing the interface. All options are defined on the ``ModelAdmin``
subclass::

    from django.contrib import admin

    class AuthorAdmin(admin.ModelAdmin):
        date_hierarchy = 'pub_date'

.. attribute:: ModelAdmin.actions

    A list of actions to make available on the change list page. See
    :doc:`/ref/contrib/admin/actions` for details.

.. attribute:: ModelAdmin.actions_on_top
.. attribute:: ModelAdmin.actions_on_bottom

    Controls where on the page the actions bar appears. By default, the admin
    changelist displays actions at the top of the page (``actions_on_top = True;
    actions_on_bottom = False``).

.. attribute:: ModelAdmin.actions_selection_counter

    Controls whether a selection counter is displayed next to the action dropdown.
    By default, the admin changelist will display it
    (``actions_selection_counter = True``).

.. attribute:: ModelAdmin.date_hierarchy

    Set ``date_hierarchy`` to the name of a ``DateField`` or ``DateTimeField``
    in your model, and the change list page will include a date-based drilldown
    navigation by that field.

    Example::

        date_hierarchy = 'pub_date'

    This will intelligently populate itself based on available data,
    e.g. if all the dates are in one month, it'll show the day-level
    drill-down only.

    .. note::

        ``date_hierarchy`` uses :meth:`QuerySet.datetimes()
        <django.db.models.query.QuerySet.datetimes>` internally. Please refer
        to its documentation for some caveats when time zone support is
        enabled (:setting:`USE_TZ = True <USE_TZ>`).

.. attribute:: ModelAdmin.exclude

    This attribute, if given, should be a list of field names to exclude from
    the form.

    For example, let's consider the following model::

        from django.db import models

        class Author(models.Model):
            name = models.CharField(max_length=100)
            title = models.CharField(max_length=3)
            birth_date = models.DateField(blank=True, null=True)

    If you want a form for the ``Author`` model that includes only the ``name``
    and ``title`` fields, you would specify ``fields`` or ``exclude`` like
    this::

        from django.contrib import admin

        class AuthorAdmin(admin.ModelAdmin):
            fields = ('name', 'title')

        class AuthorAdmin(admin.ModelAdmin):
            exclude = ('birth_date',)

    Since the Author model only has three fields, ``name``, ``title``, and
    ``birth_date``, the forms resulting from the above declarations will
    contain exactly the same fields.

.. attribute:: ModelAdmin.fields

    If you need to achieve simple changes in the layout of fields in the forms
    of the "add" and "change" pages like only showing a subset of the available
    fields, modifying their order or grouping them in rows you can use the
    ``fields`` option (for more complex layout needs see the
    :attr:`~ModelAdmin.fieldsets` option described in the next section). For
    example, you could define a simpler version of the admin form for the
    :class:`django.contrib.flatpages.models.FlatPage` model as follows::

        class FlatPageAdmin(admin.ModelAdmin):
            fields = ('url', 'title', 'content')

    In the above example, only the fields ``url``, ``title`` and ``content``
    will be displayed, sequentially, in the form. ``fields`` can contain
    values defined in :attr:`ModelAdmin.readonly_fields` to be displayed as
    read-only.

    The ``fields`` option, unlike :attr:`~ModelAdmin.list_display`, may only
    contain names of fields on the model or the form specified by
    :attr:`~ModelAdmin.form`. It may contain callables only if they are listed
    in :attr:`~ModelAdmin.readonly_fields`.

    To display multiple fields on the same line, wrap those fields in their own
    tuple. In this example, the ``url`` and ``title`` fields will display on the
    same line and the ``content`` field will be displayed below them in its
    own line::

        class FlatPageAdmin(admin.ModelAdmin):
            fields = (('url', 'title'), 'content')

    .. admonition:: Note

        This ``fields`` option should not be confused with the ``fields``
        dictionary key that is within the :attr:`~ModelAdmin.fieldsets` option,
        as described in the next section.

    If neither ``fields`` nor :attr:`~ModelAdmin.fieldsets` options are present,
    Django will default to displaying each field that isn't an ``AutoField`` and
    has ``editable=True``, in a single fieldset, in the same order as the fields
    are defined in the model.

.. attribute:: ModelAdmin.fieldsets

    Set ``fieldsets`` to control the layout of admin "add" and "change" pages.

    ``fieldsets`` is a list of two-tuples, in which each two-tuple represents a
    ``<fieldset>`` on the admin form page. (A ``<fieldset>`` is a "section" of
    the form.)

    The two-tuples are in the format ``(name, field_options)``, where ``name``
    is a string representing the title of the fieldset and ``field_options`` is
    a dictionary of information about the fieldset, including a list of fields
    to be displayed in it.

    A full example, taken from the
    :class:`django.contrib.flatpages.models.FlatPage` model::

        from django.contrib import admin

        class FlatPageAdmin(admin.ModelAdmin):
            fieldsets = (
                (None, {
                    'fields': ('url', 'title', 'content', 'sites')
                }),
                ('Advanced options', {
                    'classes': ('collapse',),
                    'fields': ('enable_comments', 'registration_required', 'template_name')
                }),
            )

    This results in an admin page that looks like:

    .. image:: _images/flatfiles_admin.png

    If neither ``fieldsets`` nor :attr:`~ModelAdmin.fields` options are present,
    Django will default to displaying each field that isn't an ``AutoField`` and
    has ``editable=True``, in a single fieldset, in the same order as the fields
    are defined in the model.

    The ``field_options`` dictionary can have the following keys:

    * ``fields``
        A tuple of field names to display in this fieldset. This key is
        required.

        Example::

            {
            'fields': ('first_name', 'last_name', 'address', 'city', 'state'),
            }

        As with the :attr:`~ModelAdmin.fields` option, to display multiple
        fields on the same line, wrap those fields in their own tuple. In this
        example, the ``first_name`` and ``last_name`` fields will display on
        the same line::

            {
            'fields': (('first_name', 'last_name'), 'address', 'city', 'state'),
            }

        ``fields`` can contain values defined in
        :attr:`~ModelAdmin.readonly_fields` to be displayed as read-only.

        If you add the name of a callable to ``fields``, the same rule applies
        as with the :attr:`~ModelAdmin.fields` option: the callable must be
        listed in :attr:`~ModelAdmin.readonly_fields`.

    * ``classes``
        A list containing extra CSS classes to apply to the fieldset.

        Example::

            {
            'classes': ('wide', 'extrapretty'),
            }

        Two useful classes defined by the default admin site stylesheet are
        ``collapse`` and ``wide``. Fieldsets with the ``collapse`` style
        will be initially collapsed in the admin and replaced with a small
        "click to expand" link. Fieldsets with the ``wide`` style will be
        given extra horizontal space.

    * ``description``
        A string of optional extra text to be displayed at the top of each
        fieldset, under the heading of the fieldset. This string is not
        rendered for :class:`~django.contrib.admin.TabularInline` due to its
        layout.

        Note that this value is *not* HTML-escaped when it's displayed in
        the admin interface. This lets you include HTML if you so desire.
        Alternatively you can use plain text and
        ``django.utils.html.escape()`` to escape any HTML special
        characters.

.. attribute:: ModelAdmin.filter_horizontal

    By default, a :class:`~django.db.models.ManyToManyField` is displayed in
    the admin site with a ``<select multiple>``. However, multiple-select boxes
    can be difficult to use when selecting many items. Adding a
    :class:`~django.db.models.ManyToManyField` to this list will instead use
    a nifty unobtrusive JavaScript "filter" interface that allows searching
    within the options. The unselected and selected options appear in two boxes
    side by side. See :attr:`~ModelAdmin.filter_vertical` to use a vertical
    interface.

.. attribute:: ModelAdmin.filter_vertical

    Same as :attr:`~ModelAdmin.filter_horizontal`, but uses a vertical display
    of the filter interface with the box of unselected options appearing above
    the box of selected options.

.. attribute:: ModelAdmin.form

    By default a ``ModelForm`` is dynamically created for your model. It is
    used to create the form presented on both the add/change pages. You can
    easily provide your own ``ModelForm`` to override any default form behavior
    on the add/change pages. Alternatively, you can customize the default
    form rather than specifying an entirely new one by using the
    :meth:`ModelAdmin.get_form` method.

    For an example see the section :ref:`admin-custom-validation`.

    .. admonition:: Note

        If you define the ``Meta.model`` attribute on a
        :class:`~django.forms.ModelForm`, you must also define the
        ``Meta.fields`` attribute (or the ``Meta.exclude`` attribute). However,
        since the admin has its own way of defining fields, the ``Meta.fields``
        attribute will be ignored.

        If the ``ModelForm`` is only going to be used for the admin, the easiest
        solution is to omit the ``Meta.model`` attribute, since ``ModelAdmin``
        will provide the correct model to use. Alternatively, you can set
        ``fields = []`` in the ``Meta`` class to satisfy the validation on the
        ``ModelForm``.

    .. admonition:: Note

        If your ``ModelForm`` and ``ModelAdmin`` both define an ``exclude``
        option then ``ModelAdmin`` takes precedence::

            from django import forms
            from django.contrib import admin
            from myapp.models import Person

            class PersonForm(forms.ModelForm):

                class Meta:
                    model = Person
                    exclude = ['name']

            class PersonAdmin(admin.ModelAdmin):
                exclude = ['age']
                form = PersonForm

        In the above example, the "age" field will be excluded but the "name"
        field will be included in the generated form.

.. attribute:: ModelAdmin.formfield_overrides

    This provides a quick-and-dirty way to override some of the
    :class:`~django.forms.Field` options for use in the admin.
    ``formfield_overrides`` is a dictionary mapping a field class to a dict of
    arguments to pass to the field at construction time.

    Since that's a bit abstract, let's look at a concrete example. The most
    common use of ``formfield_overrides`` is to add a custom widget for a
    certain type of field. So, imagine we've written a ``RichTextEditorWidget``
    that we'd like to use for large text fields instead of the default
    ``<textarea>``. Here's how we'd do that::

        from django.db import models
        from django.contrib import admin

        # Import our custom widget and our model from where they're defined
        from myapp.widgets import RichTextEditorWidget
        from myapp.models import MyModel

        class MyModelAdmin(admin.ModelAdmin):
            formfield_overrides = {
                models.TextField: {'widget': RichTextEditorWidget},
            }

    Note that the key in the dictionary is the actual field class, *not* a
    string. The value is another dictionary; these arguments will be passed to
    the form field's ``__init__()`` method. See :doc:`/ref/forms/api` for
    details.

    .. warning::

        If you want to use a custom widget with a relation field (i.e.
        :class:`~django.db.models.ForeignKey` or
        :class:`~django.db.models.ManyToManyField`), make sure you haven't
        included that field's name in ``raw_id_fields`` or ``radio_fields``.

        ``formfield_overrides`` won't let you change the widget on relation
        fields that have ``raw_id_fields`` or ``radio_fields`` set. That's
        because ``raw_id_fields`` and ``radio_fields`` imply custom widgets of
        their own.

.. attribute:: ModelAdmin.inlines

    See :class:`InlineModelAdmin` objects below as well as
    :meth:`ModelAdmin.get_formsets_with_inlines`.

.. attribute:: ModelAdmin.list_display

    Set ``list_display`` to control which fields are displayed on the change
    list page of the admin.

    Example::

        list_display = ('first_name', 'last_name')

    If you don't set ``list_display``, the admin site will display a single
    column that displays the ``__str__()`` (``__unicode__()`` on Python 2)
    representation of each object.

    You have four possible values that can be used in ``list_display``:

    * A field of the model. For example::

          class PersonAdmin(admin.ModelAdmin):
              list_display = ('first_name', 'last_name')

    * A callable that accepts one parameter for the model instance. For
      example::

          def upper_case_name(obj):
              return ("%s %s" % (obj.first_name, obj.last_name)).upper()
          upper_case_name.short_description = 'Name'

          class PersonAdmin(admin.ModelAdmin):
              list_display = (upper_case_name,)

    * A string representing an attribute on the ``ModelAdmin``. This
      behaves same as the callable. For example::

          class PersonAdmin(admin.ModelAdmin):
              list_display = ('upper_case_name',)

              def upper_case_name(self, obj):
                  return ("%s %s" % (obj.first_name, obj.last_name)).upper()
              upper_case_name.short_description = 'Name'

    * A string representing an attribute on the model. This behaves almost
      the same as the callable, but ``self`` in this context is the model
      instance. Here's a full model example::

          from django.db import models
          from django.contrib import admin

          class Person(models.Model):
              name = models.CharField(max_length=50)
              birthday = models.DateField()

              def decade_born_in(self):
                  return self.birthday.strftime('%Y')[:3] + "0's"
              decade_born_in.short_description = 'Birth decade'

          class PersonAdmin(admin.ModelAdmin):
              list_display = ('name', 'decade_born_in')

    A few special cases to note about ``list_display``:

    * If the field is a ``ForeignKey``, Django will display the
      ``__str__()`` (``__unicode__()`` on Python 2) of the related object.

    * ``ManyToManyField`` fields aren't supported, because that would
      entail executing a separate SQL statement for each row in the table.
      If you want to do this nonetheless, give your model a custom method,
      and add that method's name to ``list_display``. (See below for more
      on custom methods in ``list_display``.)

    * If the field is a ``BooleanField`` or ``NullBooleanField``, Django
      will display a pretty "on" or "off" icon instead of ``True`` or
      ``False``.

    * If the string given is a method of the model, ``ModelAdmin`` or a
      callable, Django will HTML-escape the output by default. If you'd
      rather not escape the output of the method, give the method an
      ``allow_tags`` attribute whose value is ``True``. However, to avoid an
      XSS vulnerability, you should use :func:`~django.utils.html.format_html`
      to escape user-provided inputs.

      Here's a full example model::

          from django.db import models
          from django.contrib import admin
          from django.utils.html import format_html

          class Person(models.Model):
              first_name = models.CharField(max_length=50)
              last_name = models.CharField(max_length=50)
              color_code = models.CharField(max_length=6)

              def colored_name(self):
                  return format_html('<span style="color: #{};">{} {}</span>',
                                     self.color_code,
                                     self.first_name,
                                     self.last_name)

              colored_name.allow_tags = True

          class PersonAdmin(admin.ModelAdmin):
              list_display = ('first_name', 'last_name', 'colored_name')

    * If the string given is a method of the model, ``ModelAdmin`` or a
      callable that returns True or False Django will display a pretty
      "on" or "off" icon if you give the method a ``boolean`` attribute
      whose value is ``True``.

      Here's a full example model::

          from django.db import models
          from django.contrib import admin

          class Person(models.Model):
              first_name = models.CharField(max_length=50)
              birthday = models.DateField()

              def born_in_fifties(self):
                  return self.birthday.strftime('%Y')[:3] == '195'
              born_in_fifties.boolean = True

          class PersonAdmin(admin.ModelAdmin):
              list_display = ('name', 'born_in_fifties')


    * The ``__str__()`` (``__unicode__()`` on Python 2) method is just
      as valid in ``list_display`` as any other model method, so it's
      perfectly OK to do this::

          list_display = ('__str__', 'some_other_field')

    * Usually, elements of ``list_display`` that aren't actual database
      fields can't be used in sorting (because Django does all the sorting
      at the database level).

      However, if an element of ``list_display`` represents a certain
      database field, you can indicate this fact by setting the
      ``admin_order_field`` attribute of the item.

      For example::

        from django.db import models
        from django.contrib import admin
        from django.utils.html import format_html

        class Person(models.Model):
            first_name = models.CharField(max_length=50)
            color_code = models.CharField(max_length=6)

            def colored_first_name(self):
                return format_html('<span style="color: #{};">{}</span>',
                                   self.color_code,
                                   self.first_name)

            colored_first_name.allow_tags = True
            colored_first_name.admin_order_field = 'first_name'

        class PersonAdmin(admin.ModelAdmin):
            list_display = ('first_name', 'colored_first_name')

      The above will tell Django to order by the ``first_name`` field when
      trying to sort by ``colored_first_name`` in the admin.

      To indicate descending order with ``admin_order_field`` you can use a
      hyphen prefix on the field name. Using the above example, this would
      look like::

          colored_first_name.admin_order_field = '-first_name'

    * Elements of ``list_display`` can also be properties. Please note however,
      that due to the way properties work in Python, setting
      ``short_description`` on a property is only possible when using the
      ``property()`` function and **not** with the ``@property`` decorator.

      For example::

          class Person(models.Model):
              first_name = models.CharField(max_length=50)
              last_name = models.CharField(max_length=50)

              def my_property(self):
                  return self.first_name + ' ' + self.last_name
              my_property.short_description = "Full name of the person"

              full_name = property(my_property)

          class PersonAdmin(admin.ModelAdmin):
              list_display = ('full_name',)


    * The field names in ``list_display`` will also appear as CSS classes in
      the HTML output, in the form of ``column-<field_name>`` on each ``<th>``
      element. This can be used to set column widths in a CSS file for example.

    * Django will try to interpret every element of ``list_display`` in this
      order:

      * A field of the model.
      * A callable.
      * A string representing a ``ModelAdmin`` attribute.
      * A string representing a model attribute.

      For example if you have ``first_name`` as a model field and
      as a ``ModelAdmin`` attribute, the model field will be used.


.. attribute:: ModelAdmin.list_display_links

    Use ``list_display_links`` to control if and which fields in
    :attr:`list_display` should be linked to the "change" page for an object.

    By default, the change list page will link the first column -- the first
    field specified in ``list_display`` -- to the change page for each item.
    But ``list_display_links`` lets you change this:

    * Set it to ``None`` to get no links at all.
    * Set it to a list or tuple of fields (in the same format as
      ``list_display``) whose columns you want converted to links.

      You can specify one or many fields. As long as the fields appear in
      ``list_display``, Django doesn't care how many (or how few) fields are
      linked. The only requirement is that if you want to use
      ``list_display_links`` in this fashion, you must define ``list_display``.

    In this example, the ``first_name`` and ``last_name`` fields will be
    linked on the change list page::

        class PersonAdmin(admin.ModelAdmin):
            list_display = ('first_name', 'last_name', 'birthday')
            list_display_links = ('first_name', 'last_name')

    In this example, the change list page grid will have no links::

        class AuditEntryAdmin(admin.ModelAdmin):
            list_display = ('timestamp', 'message')
            list_display_links = None

.. _admin-list-editable:

.. attribute:: ModelAdmin.list_editable

    Set ``list_editable`` to a list of field names on the model which will
    allow editing on the change list page. That is, fields listed in
    ``list_editable`` will be displayed as form widgets on the change list
    page, allowing users to edit and save multiple rows at once.

    .. note::

        ``list_editable`` interacts with a couple of other options in
        particular ways; you should note the following rules:

        * Any field in ``list_editable`` must also be in ``list_display``.
          You can't edit a field that's not displayed!

        * The same field can't be listed in both ``list_editable`` and
          ``list_display_links`` -- a field can't be both a form and
          a link.

        You'll get a validation error if either of these rules are broken.

.. attribute:: ModelAdmin.list_filter

    Set ``list_filter`` to activate filters in the right sidebar of the change
    list page of the admin, as illustrated in the following screenshot:

    .. image:: _images/users_changelist.png

    ``list_filter`` should be a list or tuple of elements, where each element
    should be of one of the following types:

    * a field name, where the specified field should be either a
      ``BooleanField``, ``CharField``, ``DateField``, ``DateTimeField``,
      ``IntegerField``, ``ForeignKey`` or ``ManyToManyField``, for example::

          class PersonAdmin(admin.ModelAdmin):
              list_filter = ('is_staff', 'company')

      Field names in ``list_filter`` can also span relations
      using the ``__`` lookup, for example::

          class PersonAdmin(admin.UserAdmin):
              list_filter = ('company__name',)

    * a class inheriting from ``django.contrib.admin.SimpleListFilter``,
      which you need to provide the ``title`` and ``parameter_name``
      attributes to and override the ``lookups`` and ``queryset`` methods,
      e.g.::

           from datetime import date

           from django.contrib import admin
           from django.utils.translation import ugettext_lazy as _

           class DecadeBornListFilter(admin.SimpleListFilter):
               # Human-readable title which will be displayed in the
               # right admin sidebar just above the filter options.
               title = _('decade born')

               # Parameter for the filter that will be used in the URL query.
               parameter_name = 'decade'

               def lookups(self, request, model_admin):
                   """
                   Returns a list of tuples. The first element in each
                   tuple is the coded value for the option that will
                   appear in the URL query. The second element is the
                   human-readable name for the option that will appear
                   in the right sidebar.
                   """
                   return (
                       ('80s', _('in the eighties')),
                       ('90s', _('in the nineties')),
                   )

               def queryset(self, request, queryset):
                   """
                   Returns the filtered queryset based on the value
                   provided in the query string and retrievable via
                   `self.value()`.
                   """
                   # Compare the requested value (either '80s' or '90s')
                   # to decide how to filter the queryset.
                   if self.value() == '80s':
                       return queryset.filter(birthday__gte=date(1980, 1, 1),
                                               birthday__lte=date(1989, 12, 31))
                   if self.value() == '90s':
                       return queryset.filter(birthday__gte=date(1990, 1, 1),
                                               birthday__lte=date(1999, 12, 31))

           class PersonAdmin(admin.ModelAdmin):
               list_filter = (DecadeBornListFilter,)

      .. note::

          As a convenience, the ``HttpRequest`` object is passed to the
          ``lookups`` and ``queryset`` methods, for example::

              class AuthDecadeBornListFilter(DecadeBornListFilter):

                  def lookups(self, request, model_admin):
                      if request.user.is_superuser:
                          return super(AuthDecadeBornListFilter,
                              self).lookups(request, model_admin)

                  def queryset(self, request, queryset):
                      if request.user.is_superuser:
                          return super(AuthDecadeBornListFilter,
                              self).queryset(request, queryset)

          Also as a convenience, the ``ModelAdmin`` object is passed to
          the ``lookups`` method, for example if you want to base the
          lookups on the available data::

              class AdvancedDecadeBornListFilter(DecadeBornListFilter):

                  def lookups(self, request, model_admin):
                      """
                      Only show the lookups if there actually is
                      anyone born in the corresponding decades.
                      """
                      qs = model_admin.get_queryset(request)
                      if qs.filter(birthday__gte=date(1980, 1, 1),
                                    birthday__lte=date(1989, 12, 31)).exists():
                          yield ('80s', _('in the eighties'))
                      if qs.filter(birthday__gte=date(1990, 1, 1),
                                    birthday__lte=date(1999, 12, 31)).exists():
                          yield ('90s', _('in the nineties'))

    * a tuple, where the first element is a field name and the second
      element is a class inheriting from
      ``django.contrib.admin.FieldListFilter``, for example::

          class PersonAdmin(admin.ModelAdmin):
              list_filter = (
                  ('is_staff', admin.BooleanFieldListFilter),
              )

      .. versionadded:: 1.8

      You can now limit the choices of a related model to the objects
      involved in that relation using ``RelatedOnlyFieldListFilter``::

          class BookAdmin(admin.ModelAdmin):
              list_filter = (
                  ('author', admin.RelatedOnlyFieldListFilter),
              )

      Assuming ``author`` is a ``ForeignKey`` to a ``User`` model, this will
      limit the ``list_filter`` choices to the users who have written a book
      instead of listing all users.

      .. note::

        The ``FieldListFilter`` API is considered internal and might be
        changed.

    It is possible to specify a custom template for rendering a list filter::

        class FilterWithCustomTemplate(admin.SimpleListFilter):
            template = "custom_template.html"

    See the default template provided by django (``admin/filter.html``) for
    a concrete example.

.. attribute:: ModelAdmin.list_max_show_all

    Set ``list_max_show_all`` to control how many items can appear on a "Show
    all" admin change list page. The admin will display a "Show all" link on the
    change list only if the total result count is less than or equal to this
    setting. By default, this is set to ``200``.

.. attribute:: ModelAdmin.list_per_page

    Set ``list_per_page`` to control how many items appear on each paginated
    admin change list page. By default, this is set to ``100``.

.. attribute:: ModelAdmin.list_select_related

    Set ``list_select_related`` to tell Django to use
    :meth:`~django.db.models.query.QuerySet.select_related` in retrieving
    the list of objects on the admin change list page. This can save you a
    bunch of database queries.

    The value should be either a boolean, a list or a tuple. Default is
    ``False``.

    When value is ``True``, ``select_related()`` will always be called. When
    value is set to ``False``, Django will look at ``list_display`` and call
    ``select_related()`` if any ``ForeignKey`` is present.

    If you need more fine-grained control, use a tuple (or list) as value for
    ``list_select_related``. Empty tuple will prevent Django from calling
    ``select_related`` at all. Any other tuple will be passed directly to
    ``select_related`` as parameters. For example::

        class ArticleAdmin(admin.ModelAdmin):
            list_select_related = ('author', 'category')

    will call ``select_related('author', 'category')``.

    If you need to specify a dynamic value based on the request, you can
    implement a :meth:`~ModelAdmin.get_list_select_related` method.

.. attribute:: ModelAdmin.ordering

    Set ``ordering`` to specify how lists of objects should be ordered in the
    Django admin views. This should be a list or tuple in the same format as a
    model's :attr:`~django.db.models.Options.ordering` parameter.

    If this isn't provided, the Django admin will use the model's default
    ordering.

    If you need to specify a dynamic order (for example depending on user or
    language) you can implement a :meth:`~ModelAdmin.get_ordering` method.

.. attribute:: ModelAdmin.paginator

    The paginator class to be used for pagination. By default,
    :class:`django.core.paginator.Paginator` is used. If the custom paginator
    class doesn't have the same constructor interface as
    :class:`django.core.paginator.Paginator`, you will also need to
    provide an implementation for :meth:`ModelAdmin.get_paginator`.

.. attribute:: ModelAdmin.prepopulated_fields

    Set ``prepopulated_fields`` to a dictionary mapping field names to the
    fields it should prepopulate from::

        class ArticleAdmin(admin.ModelAdmin):
            prepopulated_fields = {"slug": ("title",)}

    When set, the given fields will use a bit of JavaScript to populate from
    the fields assigned. The main use for this functionality is to
    automatically generate the value for ``SlugField`` fields from one or more
    other fields. The generated value is produced by concatenating the values
    of the source fields, and then by transforming that result into a valid
    slug (e.g. substituting dashes for spaces).

    ``prepopulated_fields`` doesn't accept ``DateTimeField``, ``ForeignKey``,
    nor ``ManyToManyField`` fields.

.. attribute:: ModelAdmin.preserve_filters

    The admin now preserves filters on the list view after creating, editing
    or deleting an object. You can restore the previous behavior of clearing
    filters by setting this attribute to ``False``.

.. attribute:: ModelAdmin.radio_fields

    By default, Django's admin uses a select-box interface (<select>) for
    fields that are ``ForeignKey`` or have ``choices`` set. If a field is
    present in ``radio_fields``, Django will use a radio-button interface
    instead. Assuming ``group`` is a ``ForeignKey`` on the ``Person`` model::

        class PersonAdmin(admin.ModelAdmin):
            radio_fields = {"group": admin.VERTICAL}

    You have the choice of using ``HORIZONTAL`` or ``VERTICAL`` from the
    ``django.contrib.admin`` module.

    Don't include a field in ``radio_fields`` unless it's a ``ForeignKey`` or has
    ``choices`` set.

.. attribute:: ModelAdmin.raw_id_fields

    By default, Django's admin uses a select-box interface (<select>) for
    fields that are ``ForeignKey``. Sometimes you don't want to incur the
    overhead of having to select all the related instances to display in the
    drop-down.

    ``raw_id_fields`` is a list of fields you would like to change
    into an ``Input`` widget for either a ``ForeignKey`` or
    ``ManyToManyField``::

        class ArticleAdmin(admin.ModelAdmin):
            raw_id_fields = ("newspaper",)

    The ``raw_id_fields`` ``Input`` widget should contain a primary key if the
    field is a ``ForeignKey`` or a comma separated list of values if the field
    is a ``ManyToManyField``.  The ``raw_id_fields`` widget shows a magnifying
    glass button next to the field which allows users to search for and select
    a value:

    .. image:: _images/raw_id_fields.png

.. attribute:: ModelAdmin.readonly_fields

    By default the admin shows all fields as editable. Any fields in this
    option (which should be a ``list`` or ``tuple``) will display its data
    as-is and non-editable; they are also excluded from the
    :class:`~django.forms.ModelForm` used for creating and editing. Note that
    when specifying :attr:`ModelAdmin.fields` or :attr:`ModelAdmin.fieldsets`
    the read-only fields must be present to be shown (they are ignored
    otherwise).

    If ``readonly_fields`` is used without defining explicit ordering through
    :attr:`ModelAdmin.fields` or :attr:`ModelAdmin.fieldsets` they will be
    added last after all editable fields.

    A read-only field can not only display data from a model's field, it can
    also display the output of a model's method or a method of the
    ``ModelAdmin`` class itself. This is very similar to the way
    :attr:`ModelAdmin.list_display` behaves. This provides an easy way to use
    the admin interface to provide feedback on the status of the objects being
    edited, for example::

        from django.contrib import admin
        from django.utils.html import format_html_join
        from django.utils.safestring import mark_safe

        class PersonAdmin(admin.ModelAdmin):
            readonly_fields = ('address_report',)

            def address_report(self, instance):
                # assuming get_full_address() returns a list of strings
                # for each line of the address and you want to separate each
                # line by a linebreak
                return format_html_join(
                    mark_safe('<br/>'),
                    '{}',
                    ((line,) for line in instance.get_full_address()),
                ) or "<span class='errors'>I can't determine this address.</span>"

            # short_description functions like a model field's verbose_name
            address_report.short_description = "Address"
            # in this example, we have used HTML tags in the output
            address_report.allow_tags = True

.. attribute:: ModelAdmin.save_as

    Set ``save_as`` to enable a "save as" feature on admin change forms.

    Normally, objects have three save options: "Save", "Save and continue
    editing" and "Save and add another". If ``save_as`` is ``True``, "Save
    and add another" will be replaced by a "Save as" button.

    "Save as" means the object will be saved as a new object (with a new ID),
    rather than the old object.

    By default, ``save_as`` is set to ``False``.

.. attribute:: ModelAdmin.save_on_top

    Set ``save_on_top`` to add save buttons across the top of your admin change
    forms.

    Normally, the save buttons appear only at the bottom of the forms. If you
    set ``save_on_top``, the buttons will appear both on the top and the
    bottom.

    By default, ``save_on_top`` is set to ``False``.

.. attribute:: ModelAdmin.search_fields

    Set ``search_fields`` to enable a search box on the admin change list page.
    This should be set to a list of field names that will be searched whenever
    somebody submits a search query in that text box.

    These fields should be some kind of text field, such as ``CharField`` or
    ``TextField``. You can also perform a related lookup on a ``ForeignKey`` or
    ``ManyToManyField`` with the lookup API "follow" notation::

        search_fields = ['foreign_key__related_fieldname']

    For example, if you have a blog entry with an author, the following
    definition would enable search blog entries by the email address of the
    author::

        search_fields = ['user__email']

    When somebody does a search in the admin search box, Django splits the
    search query into words and returns all objects that contain each of the
    words, case insensitive, where each word must be in at least one of
    ``search_fields``. For example, if ``search_fields`` is set to
    ``['first_name', 'last_name']`` and a user searches for ``john lennon``,
    Django will do the equivalent of this SQL ``WHERE`` clause::

        WHERE (first_name ILIKE '%john%' OR last_name ILIKE '%john%')
        AND (first_name ILIKE '%lennon%' OR last_name ILIKE '%lennon%')

    For faster and/or more restrictive searches, prefix the field name
    with an operator:

    ``^``
        Matches the beginning of the field. For example, if ``search_fields``
        is set to ``['^first_name', '^last_name']`` and a user searches for
        ``john lennon``, Django will do the equivalent of this SQL ``WHERE``
        clause::

            WHERE (first_name ILIKE 'john%' OR last_name ILIKE 'john%')
            AND (first_name ILIKE 'lennon%' OR last_name ILIKE 'lennon%')

        This query is more efficient than the normal ``'%john%'`` query,
        because the database only needs to check the beginning of a column's
        data, rather than seeking through the entire column's data. Plus, if
        the column has an index on it, some databases may be able to use the
        index for this query, even though it's a ``LIKE`` query.

    ``=``
        Matches exactly, case-insensitive. For example, if
        ``search_fields`` is set to ``['=first_name', '=last_name']`` and
        a user searches for ``john lennon``, Django will do the equivalent
        of this SQL ``WHERE`` clause::

            WHERE (first_name ILIKE 'john' OR last_name ILIKE 'john')
            AND (first_name ILIKE 'lennon' OR last_name ILIKE 'lennon')

        Note that the query input is split by spaces, so, following this
        example, it's currently not possible to search for all records in which
        ``first_name`` is exactly ``'john winston'`` (containing a space).

    ``@``
        Performs a full-text match. This is like the default search method but
        uses an index. Currently this is only available for MySQL.

    If you need to customize search you can use
    :meth:`ModelAdmin.get_search_results` to provide additional or alternate
    search behavior.

.. attribute:: ModelAdmin.show_full_result_count

    .. versionadded:: 1.8

    Set ``show_full_result_count`` to control whether the full count of objects
    should be displayed on a filtered admin page (e.g. ``99 results (103 total)``).
    If this option is set to ``False``, a text like ``99 results (Show all)``
    is displayed instead.

    The default of ``show_full_result_count=True`` generates a query to perform
    a full count on the table which can be expensive if the table contains a
    large number of rows.

.. attribute:: ModelAdmin.view_on_site

    Set ``view_on_site`` to control whether or not to display the "View on site" link.
    This link should bring you to a URL where you can display the saved object.

    This value can be either a boolean flag or a callable. If ``True`` (the
    default), the object's :meth:`~django.db.models.Model.get_absolute_url`
    method will be used to generate the url.

    If your model has a :meth:`~django.db.models.Model.get_absolute_url` method
    but you don't want the "View on site" button to appear, you only need to set
    ``view_on_site`` to ``False``::

        from django.contrib import admin

        class PersonAdmin(admin.ModelAdmin):
            view_on_site = False

    In case it is a callable, it accepts the model instance as a parameter.
    For example::

        from django.contrib import admin
        from django.core.urlresolvers import reverse

        class PersonAdmin(admin.ModelAdmin):
            def view_on_site(self, obj):
                return 'http://example.com' + reverse('person-detail',
                                                      kwargs={'slug': obj.slug})

Custom template options
~~~~~~~~~~~~~~~~~~~~~~~

The :ref:`admin-overriding-templates` section describes how to override or extend
the default admin templates.  Use the following options to override the default
templates used by the :class:`ModelAdmin` views:

.. attribute:: ModelAdmin.add_form_template

    Path to a custom template, used by :meth:`add_view`.

.. attribute:: ModelAdmin.change_form_template

    Path to a custom template, used by :meth:`change_view`.

.. attribute:: ModelAdmin.change_list_template

    Path to a custom template, used by :meth:`changelist_view`.

.. attribute:: ModelAdmin.delete_confirmation_template

    Path to a custom template, used by :meth:`delete_view` for displaying a
    confirmation page when deleting one or more objects.

.. attribute:: ModelAdmin.delete_selected_confirmation_template

    Path to a custom template, used by the ``delete_selected`` action method
    for displaying a confirmation page when deleting one or more objects. See
    the :doc:`actions documentation</ref/contrib/admin/actions>`.

.. attribute:: ModelAdmin.object_history_template

    Path to a custom template, used by :meth:`history_view`.


.. _model-admin-methods:

``ModelAdmin`` methods
----------------------

.. warning::

    :meth:`ModelAdmin.save_model` and :meth:`ModelAdmin.delete_model` must
    save/delete the object, they are not for veto purposes, rather they allow
    you to perform extra operations.

.. method:: ModelAdmin.save_model(request, obj, form, change)

    The ``save_model`` method is given the ``HttpRequest``, a model instance,
    a ``ModelForm`` instance and a boolean value based on whether it is adding
    or changing the object. Here you can do any pre- or post-save operations.

    For example to attach ``request.user`` to the object prior to saving::

        from django.contrib import admin

        class ArticleAdmin(admin.ModelAdmin):
            def save_model(self, request, obj, form, change):
                obj.user = request.user
                obj.save()

.. method:: ModelAdmin.delete_model(request, obj)

    The ``delete_model`` method is given the ``HttpRequest`` and a model
    instance. Use this method to do pre- or post-delete operations.

.. method:: ModelAdmin.save_formset(request, form, formset, change)

    The ``save_formset`` method is given the ``HttpRequest``, the parent
    ``ModelForm`` instance and a boolean value based on whether it is adding or
    changing the parent object.

    For example, to attach ``request.user`` to each changed formset
    model instance::

        class ArticleAdmin(admin.ModelAdmin):
            def save_formset(self, request, form, formset, change):
                instances = formset.save(commit=False)
                for obj in formset.deleted_objects:
                    obj.delete()
                for instance in instances:
                    instance.user = request.user
                    instance.save()
                formset.save_m2m()

    See also :ref:`saving-objects-in-the-formset`.

.. method:: ModelAdmin.get_ordering(request)

    The ``get_ordering`` method takes a``request`` as parameter and
    is expected to return a ``list`` or ``tuple`` for ordering similar
    to the :attr:`ordering` attribute. For example::

        class PersonAdmin(admin.ModelAdmin):

            def get_ordering(self, request):
                if request.user.is_superuser:
                    return ['name', 'rank']
                else:
                    return ['name']

.. method:: ModelAdmin.get_search_results(request, queryset, search_term)

    The ``get_search_results`` method modifies the list of objects displayed in
    to those that match the provided search term. It accepts the request, a
    queryset that applies the current filters, and the user-provided search term.
    It returns a tuple containing a queryset modified to implement the search, and
    a boolean indicating if the results may contain duplicates.

    The default implementation searches the fields named in :attr:`ModelAdmin.search_fields`.

    This method may be overridden with your own custom search method. For
    example, you might wish to search by an integer field, or use an external
    tool such as Solr or Haystack. You must establish if the queryset changes
    implemented by your search method may introduce duplicates into the results,
    and return ``True`` in the second element of the return value.

    For example, to enable search by integer field, you could use::

        class PersonAdmin(admin.ModelAdmin):
            list_display = ('name', 'age')
            search_fields = ('name',)

            def get_search_results(self, request, queryset, search_term):
                queryset, use_distinct = super(PersonAdmin, self).get_search_results(request, queryset, search_term)
                try:
                    search_term_as_int = int(search_term)
                except ValueError:
                    pass
                else:
                    queryset |= self.model.objects.filter(age=search_term_as_int)
                return queryset, use_distinct

.. method:: ModelAdmin.save_related(request, form, formsets, change)

    The ``save_related`` method is given the ``HttpRequest``, the parent
    ``ModelForm`` instance, the list of inline formsets and a boolean value
    based on whether the parent is being added or changed. Here you can do any
    pre- or post-save operations for objects related to the parent. Note
    that at this point the parent object and its form have already been saved.

.. method:: ModelAdmin.get_readonly_fields(request, obj=None)

    The ``get_readonly_fields`` method is given the ``HttpRequest`` and the
    ``obj`` being edited (or ``None`` on an add form) and is expected to return
    a ``list`` or ``tuple`` of field names that will be displayed as read-only,
    as described above in the :attr:`ModelAdmin.readonly_fields` section.

.. method:: ModelAdmin.get_prepopulated_fields(request, obj=None)

    The ``get_prepopulated_fields`` method is given the ``HttpRequest`` and the
    ``obj`` being edited (or ``None`` on an add form) and is expected to return
    a ``dictionary``, as described above in the :attr:`ModelAdmin.prepopulated_fields`
    section.

.. method:: ModelAdmin.get_list_display(request)

    The ``get_list_display`` method is given the ``HttpRequest`` and is
    expected to return a ``list`` or ``tuple`` of field names that will be
    displayed on the changelist view as described above in the
    :attr:`ModelAdmin.list_display` section.

.. method:: ModelAdmin.get_list_display_links(request, list_display)

    The ``get_list_display_links`` method is given the ``HttpRequest`` and
    the ``list`` or ``tuple`` returned by :meth:`ModelAdmin.get_list_display`.
    It is expected to return either ``None`` or a ``list`` or ``tuple`` of field
    names on the changelist that will be linked to the change view, as described
    in the :attr:`ModelAdmin.list_display_links` section.

.. method:: ModelAdmin.get_fields(request, obj=None)

    The ``get_fields`` method is given the ``HttpRequest`` and the ``obj``
    being edited (or ``None`` on an add form) and is expected to return a list
    of fields, as described above in the :attr:`ModelAdmin.fields` section.

.. method:: ModelAdmin.get_fieldsets(request, obj=None)

    The ``get_fieldsets`` method is given the ``HttpRequest`` and the ``obj``
    being edited (or ``None`` on an add form) and is expected to return a list
    of two-tuples, in which each two-tuple represents a ``<fieldset>`` on the
    admin form page, as described above in the :attr:`ModelAdmin.fieldsets` section.

.. method:: ModelAdmin.get_list_filter(request)

    The ``get_list_filter`` method is given the ``HttpRequest`` and is expected
    to return the same kind of sequence type as for the
    :attr:`~ModelAdmin.list_filter` attribute.

.. method:: ModelAdmin.get_list_select_related(request)

    .. versionadded:: 1.9

    The ``get_list_select_related`` method is given the ``HttpRequest`` and
    should return a boolean or list as :attr:`ModelAdmin.list_select_related`
    does.

.. method:: ModelAdmin.get_search_fields(request)

    The ``get_search_fields`` method is given the ``HttpRequest`` and is expected
    to return the same kind of sequence type as for the
    :attr:`~ModelAdmin.search_fields` attribute.

.. method:: ModelAdmin.get_inline_instances(request, obj=None)

    The ``get_inline_instances`` method is given the ``HttpRequest`` and the
    ``obj`` being edited (or ``None`` on an add form) and is expected to return
    a ``list`` or ``tuple`` of :class:`~django.contrib.admin.InlineModelAdmin`
    objects, as described below in the :class:`~django.contrib.admin.InlineModelAdmin`
    section. For example, the following would return inlines without the default
    filtering based on add, change, and delete permissions::

        class MyModelAdmin(admin.ModelAdmin):
            inlines = (MyInline,)

            def get_inline_instances(self, request, obj=None):
                return [inline(self.model, self.admin_site) for inline in self.inlines]

    If you override this method, make sure that the returned inlines are
    instances of the classes defined in :attr:`inlines` or you might encounter
    a "Bad Request" error when adding related objects.

.. method:: ModelAdmin.get_urls()

    The ``get_urls`` method on a ``ModelAdmin`` returns the URLs to be used for
    that ModelAdmin in the same way as a URLconf.  Therefore you can extend
    them as documented in :doc:`/topics/http/urls`::

        class MyModelAdmin(admin.ModelAdmin):
            def get_urls(self):
                urls = super(MyModelAdmin, self).get_urls()
                my_urls = [
                    url(r'^my_view/$', self.my_view),
                ]
                return my_urls + urls

            def my_view(self, request):
                # ...
                context = dict(
                   # Include common variables for rendering the admin template.
                   self.admin_site.each_context(request),
                   # Anything else you want in the context...
                   key=value,
                )
                return TemplateResponse(request, "sometemplate.html", context)

    If you want to use the admin layout, extend from ``admin/base_site.html``:

    .. code-block:: html+django

       {% extends "admin/base_site.html" %}
       {% block content %}
       ...
       {% endblock %}

    .. note::

        Notice that the custom patterns are included *before* the regular admin
        URLs: the admin URL patterns are very permissive and will match nearly
        anything, so you'll usually want to prepend your custom URLs to the
        built-in ones.

        In this example, ``my_view`` will be accessed at
        ``/admin/myapp/mymodel/my_view/`` (assuming the admin URLs are included
        at ``/admin/``.)

    However, the ``self.my_view`` function registered above suffers from two
    problems:

    * It will *not* perform any permission checks, so it will be accessible
      to the general public.
    * It will *not* provide any header details to prevent caching. This means
      if the page retrieves data from the database, and caching middleware is
      active, the page could show outdated information.

    Since this is usually not what you want, Django provides a convenience
    wrapper to check permissions and mark the view as non-cacheable. This
    wrapper is ``AdminSite.admin_view()`` (i.e. ``self.admin_site.admin_view``
    inside a ``ModelAdmin`` instance); use it like so::

        class MyModelAdmin(admin.ModelAdmin):
            def get_urls(self):
                urls = super(MyModelAdmin, self).get_urls()
                my_urls = [
                    url(r'^my_view/$', self.admin_site.admin_view(self.my_view))
                ]
                return my_urls + urls

    Notice the wrapped view in the fifth line above::

        url(r'^my_view/$', self.admin_site.admin_view(self.my_view))

    This wrapping will protect ``self.my_view`` from unauthorized access and
    will apply the :func:`django.views.decorators.cache.never_cache` decorator to
    make sure it is not cached if the cache middleware is active.

    If the page is cacheable, but you still want the permission check to be
    performed, you can pass a ``cacheable=True`` argument to
    ``AdminSite.admin_view()``::

        url(r'^my_view/$', self.admin_site.admin_view(self.my_view, cacheable=True))

    .. versionadded:: 1.9

    ``ModelAdmin`` views have ``model_admin`` attributes. Other
    ``AdminSite`` views have ``admin_site`` attributes.

.. method:: ModelAdmin.get_form(request, obj=None, **kwargs)

    Returns a :class:`~django.forms.ModelForm` class for use in the admin add
    and change views, see :meth:`add_view` and :meth:`change_view`.

    The base implementation uses :func:`~django.forms.models.modelform_factory`
    to subclass :attr:`~form`, modified by attributes such as :attr:`~fields`
    and :attr:`~exclude`. So, for example, if you wanted to offer additional
    fields to superusers, you could swap in a different base form like so::

        class MyModelAdmin(admin.ModelAdmin):
            def get_form(self, request, obj=None, **kwargs):
                if request.user.is_superuser:
                    kwargs['form'] = MySuperuserForm
                return super(MyModelAdmin, self).get_form(request, obj, **kwargs)

    You may also simply return a custom :class:`~django.forms.ModelForm` class
    directly.

.. method:: ModelAdmin.get_formsets_with_inlines(request, obj=None)

    Yields (``FormSet``, :class:`InlineModelAdmin`) pairs for use in admin add
    and change views.

    For example if you wanted to display a particular inline only in the change
    view, you could override ``get_formsets_with_inlines`` as follows::

        class MyModelAdmin(admin.ModelAdmin):
            inlines = [MyInline, SomeOtherInline]

            def get_formsets_with_inlines(self, request, obj=None):
                for inline in self.get_inline_instances(request, obj):
                    # hide MyInline in the add view
                    if isinstance(inline, MyInline) and obj is None:
                        continue
                    yield inline.get_formset(request, obj), inline

.. method:: ModelAdmin.formfield_for_foreignkey(db_field, request, **kwargs)

    The ``formfield_for_foreignkey`` method on a ``ModelAdmin`` allows you to
    override the default formfield for a foreign keys field. For example, to
    return a subset of objects for this foreign key field based on the user::

        class MyModelAdmin(admin.ModelAdmin):
            def formfield_for_foreignkey(self, db_field, request, **kwargs):
                if db_field.name == "car":
                    kwargs["queryset"] = Car.objects.filter(owner=request.user)
                return super(MyModelAdmin, self).formfield_for_foreignkey(db_field, request, **kwargs)

    This uses the ``HttpRequest`` instance to filter the ``Car`` foreign key
    field to only display the cars owned by the ``User`` instance.

.. method:: ModelAdmin.formfield_for_manytomany(db_field, request, **kwargs)

    Like the ``formfield_for_foreignkey`` method, the
    ``formfield_for_manytomany`` method can be overridden to change the
    default formfield for a many to many field. For example, if an owner can
    own multiple cars and cars can belong to multiple owners -- a many to
    many relationship -- you could filter the ``Car`` foreign key field to
    only display the cars owned by the ``User``::

        class MyModelAdmin(admin.ModelAdmin):
            def formfield_for_manytomany(self, db_field, request, **kwargs):
                if db_field.name == "cars":
                    kwargs["queryset"] = Car.objects.filter(owner=request.user)
                return super(MyModelAdmin, self).formfield_for_manytomany(db_field, request, **kwargs)

.. method:: ModelAdmin.formfield_for_choice_field(db_field, request, **kwargs)

    Like the ``formfield_for_foreignkey`` and ``formfield_for_manytomany``
    methods, the ``formfield_for_choice_field`` method can be overridden to
    change the default formfield for a field that has declared choices. For
    example, if the choices available to a superuser should be different than
    those available to regular staff, you could proceed as follows::

        class MyModelAdmin(admin.ModelAdmin):
            def formfield_for_choice_field(self, db_field, request, **kwargs):
                if db_field.name == "status":
                    kwargs['choices'] = (
                        ('accepted', 'Accepted'),
                        ('denied', 'Denied'),
                    )
                    if request.user.is_superuser:
                        kwargs['choices'] += (('ready', 'Ready for deployment'),)
                return super(MyModelAdmin, self).formfield_for_choice_field(db_field, request, **kwargs)

    .. admonition:: Note

        Any ``choices`` attribute set on the formfield will limited to the form
        field only. If the corresponding field on the model has choices set,
        the choices provided to the form must be a valid subset of those
        choices, otherwise the form submission will fail with
        a :exc:`~django.core.exceptions.ValidationError` when the model itself
        is validated before saving.

.. method:: ModelAdmin.get_changelist(request, **kwargs)

    Returns the ``Changelist`` class to be used for listing. By default,
    ``django.contrib.admin.views.main.ChangeList`` is used. By inheriting this
    class you can change the behavior of the listing.

.. method:: ModelAdmin.get_changelist_form(request, **kwargs)

    Returns a :class:`~django.forms.ModelForm` class for use in the ``Formset``
    on the changelist page. To use a custom form, for example::

        from django import forms

        class MyForm(forms.ModelForm):
            pass

        class MyModelAdmin(admin.ModelAdmin):
            def get_changelist_form(self, request, **kwargs):
                return MyForm

    .. admonition:: Note

        If you define the ``Meta.model`` attribute on a
        :class:`~django.forms.ModelForm`, you must also define the
        ``Meta.fields`` attribute (or the ``Meta.exclude`` attribute). However,
        ``ModelAdmin`` ignores this value, overriding it with the
        :attr:`ModelAdmin.list_editable` attribute. The easiest solution is to
        omit the ``Meta.model`` attribute, since ``ModelAdmin`` will provide the
        correct model to use.

.. method::  ModelAdmin.get_changelist_formset(request, **kwargs)

    Returns a :ref:`ModelFormSet <model-formsets>` class for use on the
    changelist page if :attr:`~ModelAdmin.list_editable` is used. To use a
    custom formset, for example::

        from django.forms.models import BaseModelFormSet

        class MyAdminFormSet(BaseModelFormSet):
            pass

        class MyModelAdmin(admin.ModelAdmin):
            def get_changelist_formset(self, request, **kwargs):
                kwargs['formset'] = MyAdminFormSet
                return super(MyModelAdmin, self).get_changelist_formset(request, **kwargs)

.. method:: ModelAdmin.has_add_permission(request)

    Should return ``True`` if adding an object is permitted, ``False``
    otherwise.

.. method:: ModelAdmin.has_change_permission(request, obj=None)

    Should return ``True`` if editing obj is permitted, ``False`` otherwise.
    If obj is ``None``, should return ``True`` or ``False`` to indicate whether
    editing of objects of this type is permitted in general (e.g., ``False``
    will be interpreted as meaning that the current user is not permitted to
    edit any object of this type).

.. method:: ModelAdmin.has_delete_permission(request, obj=None)

    Should return ``True`` if deleting obj is permitted, ``False`` otherwise.
    If obj is ``None``, should return ``True`` or ``False`` to indicate whether
    deleting objects of this type is permitted in general (e.g., ``False`` will
    be interpreted as meaning that the current user is not permitted to delete
    any object of this type).

.. method:: ModelAdmin.has_module_permission(request)

    .. versionadded:: 1.8

    Should return ``True`` if displaying the module on the admin index page and
    accessing the module's index page is permitted, ``False`` otherwise.
    Uses :meth:`User.has_module_perms()
    <django.contrib.auth.models.User.has_module_perms>` by default. Overriding
    it does not restrict access to the add, change or delete views,
    :meth:`~ModelAdmin.has_add_permission`,
    :meth:`~ModelAdmin.has_change_permission`, and
    :meth:`~ModelAdmin.has_delete_permission` should be used for that.

.. method:: ModelAdmin.get_queryset(request)

    The ``get_queryset`` method on a ``ModelAdmin`` returns a
    :class:`~django.db.models.query.QuerySet` of all model instances that
    can be edited by the admin site. One use case for overriding this method
    is to show objects owned by the logged-in user::

        class MyModelAdmin(admin.ModelAdmin):
            def get_queryset(self, request):
                qs = super(MyModelAdmin, self).get_queryset(request)
                if request.user.is_superuser:
                    return qs
                return qs.filter(author=request.user)

.. method:: ModelAdmin.message_user(request, message, level=messages.INFO, extra_tags='', fail_silently=False)

    Sends a message to the user using the :mod:`django.contrib.messages`
    backend.  See the :ref:`custom ModelAdmin example <custom-admin-action>`.

    Keyword arguments allow you to change the message level, add extra CSS
    tags, or fail silently if the ``contrib.messages`` framework is not
    installed. These keyword arguments match those for
    :func:`django.contrib.messages.add_message`, see that function's
    documentation for more details. One difference is that the level may be
    passed as a string label in addition to integer/constant.

.. method:: ModelAdmin.get_paginator(queryset, per_page, orphans=0, allow_empty_first_page=True)

    Returns an instance of the paginator to use for this view. By default,
    instantiates an instance of :attr:`paginator`.

.. method:: ModelAdmin.response_add(request, obj, post_url_continue=None)

    Determines the :class:`~django.http.HttpResponse` for the
    :meth:`add_view` stage.

    ``response_add`` is called after the admin form is submitted and
    just after the object and all the related instances have
    been created and saved. You can override it to change the default behavior
    after the object has been created.

.. method:: ModelAdmin.response_change(request, obj)

    Determines the :class:`~django.http.HttpResponse` for the
    :meth:`change_view` stage.

    ``response_change`` is called after the admin form is submitted and
    just after the object and all the related instances have
    been saved. You can override it to change the default
    behavior after the object has been changed.

.. method:: ModelAdmin.response_delete(request, obj_display, obj_id)

    Determines the :class:`~django.http.HttpResponse` for the
    :meth:`delete_view` stage.

    ``response_delete`` is called after the object has been
    deleted. You can override it to change the default
    behavior after the object has been deleted.

    ``obj_display`` is a string with the name of the deleted
    object.

    ``obj_id`` is the serialized identifier used to retrieve the object to be
    deleted.

    .. versionadded:: 1.8

        The ``obj_id`` parameter was added.

.. method:: ModelAdmin.get_changeform_initial_data(request)

    A hook for the initial data on admin change forms. By default, fields are
    given initial values from ``GET`` parameters. For instance,
    ``?name=initial_value`` will set the ``name`` field's initial value to be
    ``initial_value``.

    This method should return a dictionary in the form
    ``{'fieldname': 'fieldval'}``::

        def get_changeform_initial_data(self, request):
            return {'name': 'custom_initial_value'}

Other methods
~~~~~~~~~~~~~

.. method:: ModelAdmin.add_view(request, form_url='', extra_context=None)

    Django view for the model instance addition page. See note below.

.. method:: ModelAdmin.change_view(request, object_id, form_url='', extra_context=None)

    Django view for the model instance edition page. See note below.

.. method:: ModelAdmin.changelist_view(request, extra_context=None)

    Django view for the model instances change list/actions page. See note
    below.

.. method:: ModelAdmin.delete_view(request, object_id, extra_context=None)

    Django view for the model instance(s) deletion confirmation page. See note
    below.

.. method:: ModelAdmin.history_view(request, object_id, extra_context=None)

    Django view for the page that shows the modification history for a given
    model instance.

Unlike the hook-type ``ModelAdmin`` methods detailed in the previous section,
these five methods are in reality designed to be invoked as Django views from
the admin application URL dispatching handler to render the pages that deal
with model instances CRUD operations. As a result, completely overriding these
methods will significantly change the behavior of the admin application.

One common reason for overriding these methods is to augment the context data
that is provided to the template that renders the view. In the following
example, the change view is overridden so that the rendered template is
provided some extra mapping data that would not otherwise be available::

    class MyModelAdmin(admin.ModelAdmin):

        # A template for a very customized change view:
        change_form_template = 'admin/myapp/extras/openstreetmap_change_form.html'

        def get_osm_info(self):
            # ...
            pass

        def change_view(self, request, object_id, form_url='', extra_context=None):
            extra_context = extra_context or {}
            extra_context['osm_data'] = self.get_osm_info()
            return super(MyModelAdmin, self).change_view(request, object_id,
                form_url, extra_context=extra_context)

These views return :class:`~django.template.response.TemplateResponse`
instances which allow you to easily customize the response data before
rendering. For more details, see the :doc:`TemplateResponse documentation
</ref/template-response>`.

.. _modeladmin-asset-definitions:

``ModelAdmin`` asset definitions
--------------------------------

There are times where you would like add a bit of CSS and/or JavaScript to
the add/change views. This can be accomplished by using a ``Media`` inner class
on your ``ModelAdmin``::

    class ArticleAdmin(admin.ModelAdmin):
        class Media:
            css = {
                "all": ("my_styles.css",)
            }
            js = ("my_code.js",)

The :doc:`staticfiles app </ref/contrib/staticfiles>` prepends
:setting:`STATIC_URL` (or :setting:`MEDIA_URL` if :setting:`STATIC_URL` is
``None``) to any asset paths. The same rules apply as :ref:`regular asset
definitions on forms <form-asset-paths>`.

jQuery
~~~~~~

Django admin JavaScript makes use of the `jQuery`_ library.

To avoid conflicts with user-supplied scripts or libraries, Django's jQuery
(version 1.11.2) is namespaced as ``django.jQuery``. If you want to use jQuery
in your own admin JavaScript without including a second copy, you can use the
``django.jQuery`` object on changelist and add/edit views.

.. versionchanged:: 1.8

    The embedded jQuery has been upgraded from 1.9.1 to 1.11.2.

The :class:`ModelAdmin` class requires jQuery by default, so there is no need
to add jQuery to your ``ModelAdmin``’s list of media resources unless you have
a specific need. For example, if you require the jQuery library to be in the
global namespace (for example when using third-party jQuery plugins) or if you
need a newer version of jQuery, you will have to include your own copy.

Django provides both uncompressed and 'minified' versions of jQuery, as
``jquery.js`` and ``jquery.min.js`` respectively.

:class:`ModelAdmin` and :class:`InlineModelAdmin` have a ``media`` property
that returns a list of ``Media`` objects which store paths to the JavaScript
files for the forms and/or formsets. If :setting:`DEBUG` is ``True`` it will
return the uncompressed versions of the various JavaScript files, including
``jquery.js``; if not, it will return the 'minified' versions.

.. _jQuery: http://jquery.com

.. _admin-custom-validation:

Adding custom validation to the admin
-------------------------------------

Adding custom validation of data in the admin is quite easy. The automatic
admin interface reuses :mod:`django.forms`, and the ``ModelAdmin`` class gives
you the ability define your own form::

    class ArticleAdmin(admin.ModelAdmin):
        form = MyArticleAdminForm

``MyArticleAdminForm`` can be defined anywhere as long as you import where
needed. Now within your form you can add your own custom validation for
any field::

    class MyArticleAdminForm(forms.ModelForm):
        def clean_name(self):
            # do something that validates your data
            return self.cleaned_data["name"]

It is important you use a ``ModelForm`` here otherwise things can break. See
the :doc:`forms </ref/forms/index>` documentation on :doc:`custom validation
</ref/forms/validation>` and, more specifically, the
:ref:`model form validation notes <overriding-modelform-clean-method>` for more
information.

.. _admin-inlines:

``InlineModelAdmin`` objects
============================

.. class:: InlineModelAdmin
.. class:: TabularInline
.. class:: StackedInline

    The admin interface has the ability to edit models on the same page as a
    parent model. These are called inlines. Suppose you have these two models::

         from django.db import models

         class Author(models.Model):
            name = models.CharField(max_length=100)

         class Book(models.Model):
            author = models.ForeignKey(Author)
            title = models.CharField(max_length=100)

    You can edit the books authored by an author on the author page. You add
    inlines to a model by specifying them in a ``ModelAdmin.inlines``::

        from django.contrib import admin

        class BookInline(admin.TabularInline):
            model = Book

        class AuthorAdmin(admin.ModelAdmin):
            inlines = [
                BookInline,
            ]

    Django provides two subclasses of ``InlineModelAdmin`` and they are:

    * :class:`~django.contrib.admin.TabularInline`
    * :class:`~django.contrib.admin.StackedInline`

    The difference between these two is merely the template used to render
    them.

``InlineModelAdmin`` options
-----------------------------

``InlineModelAdmin`` shares many of the same features as ``ModelAdmin``, and
adds some of its own (the shared features are actually defined in the
``BaseModelAdmin`` superclass). The shared features are:

- :attr:`~InlineModelAdmin.form`
- :attr:`~ModelAdmin.fieldsets`
- :attr:`~ModelAdmin.fields`
- :attr:`~ModelAdmin.formfield_overrides`
- :attr:`~ModelAdmin.exclude`
- :attr:`~ModelAdmin.filter_horizontal`
- :attr:`~ModelAdmin.filter_vertical`
- :attr:`~ModelAdmin.ordering`
- :attr:`~ModelAdmin.prepopulated_fields`
- :meth:`~ModelAdmin.get_queryset`
- :attr:`~ModelAdmin.radio_fields`
- :attr:`~ModelAdmin.readonly_fields`
- :attr:`~InlineModelAdmin.raw_id_fields`
- :meth:`~ModelAdmin.formfield_for_choice_field`
- :meth:`~ModelAdmin.formfield_for_foreignkey`
- :meth:`~ModelAdmin.formfield_for_manytomany`
- :meth:`~ModelAdmin.has_add_permission`
- :meth:`~ModelAdmin.has_change_permission`
- :meth:`~ModelAdmin.has_delete_permission`
- :meth:`~ModelAdmin.has_module_permission`

The ``InlineModelAdmin`` class adds:

.. attribute:: InlineModelAdmin.model

    The model which the inline is using. This is required.

.. attribute:: InlineModelAdmin.fk_name

    The name of the foreign key on the model. In most cases this will be dealt
    with automatically, but ``fk_name`` must be specified explicitly if there
    are more than one foreign key to the same parent model.

.. attribute:: InlineModelAdmin.formset

    This defaults to :class:`~django.forms.models.BaseInlineFormSet`. Using
    your own formset can give you many possibilities of customization. Inlines
    are built around :ref:`model formsets <model-formsets>`.

.. attribute:: InlineModelAdmin.form

    The value for ``form`` defaults to ``ModelForm``. This is what is passed
    through to :func:`~django.forms.models.inlineformset_factory` when
    creating the formset for this inline.

.. warning::
    When writing custom validation for ``InlineModelAdmin`` forms, be cautious
    of writing validation that relies on features of the parent model. If the
    parent model fails to validate, it may be left in an inconsistent state as
    described in the warning in :ref:`validation-on-modelform`.

.. attribute:: InlineModelAdmin.extra

    This controls the number of extra forms the formset will display in
    addition to the initial forms. See the
    :doc:`formsets documentation </topics/forms/formsets>` for more
    information.

    For users with JavaScript-enabled browsers, an "Add another" link is
    provided to enable any number of additional inlines to be added in addition
    to those provided as a result of the ``extra`` argument.

    The dynamic link will not appear if the number of currently displayed forms
    exceeds ``max_num``, or if the user does not have JavaScript enabled.

    :meth:`InlineModelAdmin.get_extra` also allows you to customize the number
    of extra forms.

.. attribute:: InlineModelAdmin.max_num

    This controls the maximum number of forms to show in the inline. This
    doesn't directly correlate to the number of objects, but can if the value
    is small enough. See :ref:`model-formsets-max-num` for more information.

    :meth:`InlineModelAdmin.get_max_num` also allows you to customize the
    maximum number of extra forms.

.. attribute:: InlineModelAdmin.min_num

    This controls the minimum number of forms to show in the inline.
    See :func:`~django.forms.models.modelformset_factory` for more information.

    :meth:`InlineModelAdmin.get_min_num` also allows you to customize the
    minimum number of displayed forms.

.. attribute:: InlineModelAdmin.raw_id_fields

    By default, Django's admin uses a select-box interface (<select>) for
    fields that are ``ForeignKey``. Sometimes you don't want to incur the
    overhead of having to select all the related instances to display in the
    drop-down.

    ``raw_id_fields`` is a list of fields you would like to change into a
    ``Input`` widget for either a ``ForeignKey`` or ``ManyToManyField``::

        class BookInline(admin.TabularInline):
            model = Book
            raw_id_fields = ("pages",)


.. attribute:: InlineModelAdmin.template

    The template used to render the inline on the page.

.. attribute:: InlineModelAdmin.verbose_name

    An override to the ``verbose_name`` found in the model's inner ``Meta``
    class.

.. attribute:: InlineModelAdmin.verbose_name_plural

    An override to the ``verbose_name_plural`` found in the model's inner
    ``Meta`` class.

.. attribute:: InlineModelAdmin.can_delete

    Specifies whether or not inline objects can be deleted in the inline.
    Defaults to ``True``.

.. attribute:: InlineModelAdmin.show_change_link

    .. versionadded:: 1.8

    Specifies whether or not inline objects that can be changed in the
    admin have a link to the change form. Defaults to ``False``.

.. method:: InlineModelAdmin.get_formset(request, obj=None, **kwargs)

    Returns a :class:`~django.forms.models.BaseInlineFormSet` class for use in
    admin add/change views. See the example for
    :class:`ModelAdmin.get_formsets_with_inlines`.

.. method:: InlineModelAdmin.get_extra(request, obj=None, **kwargs)

    Returns the number of extra inline forms to use. By default, returns the
    :attr:`InlineModelAdmin.extra` attribute.

    Override this method to programmatically determine the number of extra
    inline forms. For example, this may be based on the model instance
    (passed as the keyword argument ``obj``)::

        class BinaryTreeAdmin(admin.TabularInline):
            model = BinaryTree

            def get_extra(self, request, obj=None, **kwargs):
                extra = 2
                if obj:
                    return extra - obj.binarytree_set.count()
                return extra

.. method:: InlineModelAdmin.get_max_num(request, obj=None, **kwargs)

    Returns the maximum number of extra inline forms to use. By default,
    returns the :attr:`InlineModelAdmin.max_num` attribute.

    Override this method to programmatically determine the maximum number of
    inline forms. For example, this may be based on the model instance
    (passed as the keyword argument ``obj``)::

        class BinaryTreeAdmin(admin.TabularInline):
            model = BinaryTree

            def get_max_num(self, request, obj=None, **kwargs):
                max_num = 10
                if obj.parent:
                    return max_num - 5
                return max_num

.. method:: InlineModelAdmin.get_min_num(request, obj=None, **kwargs)

    Returns the minimum number of inline forms to use. By default,
    returns the :attr:`InlineModelAdmin.min_num` attribute.

    Override this method to programmatically determine the minimum number of
    inline forms. For example, this may be based on the model instance
    (passed as the keyword argument ``obj``).

Working with a model with two or more foreign keys to the same parent model
---------------------------------------------------------------------------

It is sometimes possible to have more than one foreign key to the same model.
Take this model for instance::

    from django.db import models

    class Friendship(models.Model):
        to_person = models.ForeignKey(Person, related_name="friends")
        from_person = models.ForeignKey(Person, related_name="from_friends")

If you wanted to display an inline on the ``Person`` admin add/change pages
you need to explicitly define the foreign key since it is unable to do so
automatically::

    from django.contrib import admin
    from myapp.models import Friendship

    class FriendshipInline(admin.TabularInline):
        model = Friendship
        fk_name = "to_person"

    class PersonAdmin(admin.ModelAdmin):
        inlines = [
            FriendshipInline,
        ]

Working with many-to-many models
--------------------------------

By default, admin widgets for many-to-many relations will be displayed
on whichever model contains the actual reference to the
:class:`~django.db.models.ManyToManyField`. Depending on your ``ModelAdmin``
definition, each many-to-many field in your model will be represented by a
standard HTML ``<select multiple>``, a horizontal or vertical filter, or a
``raw_id_admin`` widget. However, it is also possible to replace these
widgets with inlines.

Suppose we have the following models::

    from django.db import models

    class Person(models.Model):
        name = models.CharField(max_length=128)

    class Group(models.Model):
        name = models.CharField(max_length=128)
        members = models.ManyToManyField(Person, related_name='groups')

If you want to display many-to-many relations using an inline, you can do
so by defining an ``InlineModelAdmin`` object for the relationship::

    from django.contrib import admin

    class MembershipInline(admin.TabularInline):
        model = Group.members.through

    class PersonAdmin(admin.ModelAdmin):
        inlines = [
            MembershipInline,
        ]

    class GroupAdmin(admin.ModelAdmin):
        inlines = [
            MembershipInline,
        ]
        exclude = ('members',)

There are two features worth noting in this example.

Firstly - the ``MembershipInline`` class references ``Group.members.through``.
The ``through`` attribute is a reference to the model that manages the
many-to-many relation. This model is automatically created by Django when you
define a many-to-many field.

Secondly, the ``GroupAdmin`` must manually exclude the ``members`` field.
Django displays an admin widget for a many-to-many field on the model that
defines the relation (in this case, ``Group``). If you want to use an inline
model to represent the many-to-many relationship, you must tell Django's admin
to *not* display this widget - otherwise you will end up with two widgets on
your admin page for managing the relation.

Note that when using this technique the
:data:`~django.db.models.signals.m2m_changed` signals aren't triggered. This
is because as far as the admin is concerned, ``through`` is just a model with
two foreign key fields rather than a many-to-many relation.

In all other respects, the ``InlineModelAdmin`` is exactly the same as any
other. You can customize the appearance using any of the normal
``ModelAdmin`` properties.

Working with many-to-many intermediary models
---------------------------------------------

When you specify an intermediary model using the ``through`` argument to a
:class:`~django.db.models.ManyToManyField`, the admin will not display a
widget by default. This is because each instance of that intermediary model
requires more information than could be displayed in a single widget, and the
layout required for multiple widgets will vary depending on the intermediate
model.

However, we still want to be able to edit that information inline. Fortunately,
this is easy to do with inline admin models. Suppose we have the following
models::

    from django.db import models

    class Person(models.Model):
        name = models.CharField(max_length=128)

    class Group(models.Model):
        name = models.CharField(max_length=128)
        members = models.ManyToManyField(Person, through='Membership')

    class Membership(models.Model):
        person = models.ForeignKey(Person)
        group = models.ForeignKey(Group)
        date_joined = models.DateField()
        invite_reason = models.CharField(max_length=64)

The first step in displaying this intermediate model in the admin is to
define an inline class for the ``Membership`` model::

    class MembershipInline(admin.TabularInline):
        model = Membership
        extra = 1

This simple example uses the default ``InlineModelAdmin`` values for the
``Membership`` model, and limits the extra add forms to one. This could be
customized using any of the options available to ``InlineModelAdmin`` classes.

Now create admin views for the ``Person`` and ``Group`` models::

    class PersonAdmin(admin.ModelAdmin):
        inlines = (MembershipInline,)

    class GroupAdmin(admin.ModelAdmin):
        inlines = (MembershipInline,)

Finally, register your ``Person`` and ``Group`` models with the admin site::

    admin.site.register(Person, PersonAdmin)
    admin.site.register(Group, GroupAdmin)

Now your admin site is set up to edit ``Membership`` objects inline from
either the ``Person`` or the ``Group`` detail pages.

.. _using-generic-relations-as-an-inline:

Using generic relations as an inline
------------------------------------

It is possible to use an inline with generically related objects. Let's say
you have the following models::

    from django.db import models
    from django.contrib.contenttypes.fields import GenericForeignKey

    class Image(models.Model):
        image = models.ImageField(upload_to="images")
        content_type = models.ForeignKey(ContentType)
        object_id = models.PositiveIntegerField()
        content_object = GenericForeignKey("content_type", "object_id")

    class Product(models.Model):
        name = models.CharField(max_length=100)

If you want to allow editing and creating ``Image`` instance on the ``Product``
add/change views you can use :class:`~django.contrib.contenttypes.admin.GenericTabularInline`
or :class:`~django.contrib.contenttypes.admin.GenericStackedInline` (both
subclasses of :class:`~django.contrib.contenttypes.admin.GenericInlineModelAdmin`)
provided by :mod:`~django.contrib.contenttypes.admin`, they implement tabular and
stacked visual layouts for the forms representing the inline objects
respectively just like their non-generic counterparts and behave just like any
other inline. In your ``admin.py`` for this example app::

    from django.contrib import admin
    from django.contrib.contenttypes.admin import GenericTabularInline

    from myproject.myapp.models import Image, Product

    class ImageInline(GenericTabularInline):
        model = Image

    class ProductAdmin(admin.ModelAdmin):
        inlines = [
            ImageInline,
        ]

    admin.site.register(Product, ProductAdmin)

See the :doc:`contenttypes documentation </ref/contrib/contenttypes>` for more
specific information.

.. _admin-overriding-templates:

Overriding admin templates
==========================

It is relatively easy to override many of the templates which the admin module
uses to generate the various pages of an admin site. You can even override a
few of these templates for a specific app, or a specific model.

Set up your projects admin template directories
-----------------------------------------------

The admin template files are located in the ``contrib/admin/templates/admin``
directory.

In order to override one or more of them, first create an ``admin`` directory
in your project's ``templates`` directory. This can be any of the directories
you specified in the :setting:`DIRS <TEMPLATES-DIRS>` option of the
``DjangoTemplates`` backend in the :setting:`TEMPLATES` setting. If you have
customized the ``'loaders'`` option, be sure
``'django.template.loaders.filesystem.Loader'`` appears before
``'django.template.loaders.app_directories.Loader'`` so that your custom
templates will be found by the template loading system before those that are
included with :mod:`django.contrib.admin`.

Within this ``admin`` directory, create sub-directories named after your app.
Within these app subdirectories create sub-directories named after your models.
Note, that the admin app will lowercase the model name when looking for the
directory, so make sure you name the directory in all lowercase if you are
going to run your app on a case-sensitive filesystem.

To override an admin template for a specific app, copy and edit the template
from the ``django/contrib/admin/templates/admin`` directory, and save it to one
of the directories you just created.

For example, if we wanted to add a tool to the change list view for all the
models in an app named ``my_app``, we would copy
``contrib/admin/templates/admin/change_list.html`` to the
``templates/admin/my_app/`` directory of our project, and make any necessary
changes.

If we wanted to add a tool to the change list view for only a specific model
named 'Page', we would copy that same file to the
``templates/admin/my_app/page`` directory of our project.

Overriding vs. replacing an admin template
------------------------------------------

Because of the modular design of the admin templates, it is usually neither
necessary nor advisable to replace an entire template. It is almost always
better to override only the section of the template which you need to change.

To continue the example above, we want to add a new link next to the
``History`` tool for the ``Page`` model. After looking at ``change_form.html``
we determine that we only need to override the ``object-tools-items`` block.
Therefore here is our new ``change_form.html`` :

.. code-block:: html+django

    {% extends "admin/change_form.html" %}
    {% load i18n admin_urls %}
    {% block object-tools-items %}
        <li>
            <a href="{% url opts|admin_urlname:'history' original.pk|admin_urlquote %}" class="historylink">{% trans "History" %}</a>
        </li>
        <li>
            <a href="mylink/" class="historylink">My Link</a>
        </li>
        {% if has_absolute_url %}
            <li>
                <a href="{% url 'admin:view_on_site' content_type_id original.pk %}" class="viewsitelink">{% trans "View on site" %}</a>
            </li>
        {% endif %}
    {% endblock %}

And that's it! If we placed this file in the ``templates/admin/my_app``
directory, our link would appear on the change form for all models within
my_app.

Templates which may be overridden per app or model
--------------------------------------------------

Not every template in ``contrib/admin/templates/admin`` may be overridden per
app or per model. The following can:

* ``app_index.html``
* ``change_form.html``
* ``change_list.html``
* ``delete_confirmation.html``
* ``object_history.html``

For those templates that cannot be overridden in this way, you may still
override them for your entire project. Just place the new version in your
``templates/admin`` directory. This is particularly useful to create custom 404
and 500 pages.

.. note::

    Some of the admin templates, such as ``change_list_results.html`` are used
    to render custom inclusion tags. These may be overridden, but in such cases
    you are probably better off creating your own version of the tag in
    question and giving it a different name. That way you can use it
    selectively.

Root and login templates
------------------------

If you wish to change the index, login or logout templates, you are better off
creating your own ``AdminSite`` instance (see below), and changing the
:attr:`AdminSite.index_template` , :attr:`AdminSite.login_template` or
:attr:`AdminSite.logout_template` properties.

``AdminSite`` objects
=====================

.. class:: AdminSite(name='admin')

    A Django administrative site is represented by an instance of
    ``django.contrib.admin.sites.AdminSite``; by default, an instance of
    this class is created as ``django.contrib.admin.site`` and you can
    register your models and ``ModelAdmin`` instances with it.

    When constructing an instance of an ``AdminSite``, you can provide
    a unique instance name using the ``name`` argument to the constructor. This
    instance name is used to identify the instance, especially when
    :ref:`reversing admin URLs <admin-reverse-urls>`. If no instance name is
    provided, a default instance name of ``admin`` will be used.
    See :ref:`customizing-adminsite` for an example of customizing the
    :class:`AdminSite` class.

``AdminSite`` attributes
------------------------

Templates can override or extend base admin templates as described in
:ref:`admin-overriding-templates`.

.. attribute:: AdminSite.site_header

    The text to put at the top of each admin page, as an ``<h1>`` (a string).
    By default, this is "Django administration".

.. attribute:: AdminSite.site_title

    The text to put at the end of each admin page's ``<title>`` (a string). By
    default, this is "Django site admin".

.. attribute:: AdminSite.site_url

    .. versionadded:: 1.8

    The URL for the "View site" link at the top of each admin page. By default,
    ``site_url`` is ``/``. Set it to ``None`` to remove the link.

.. attribute:: AdminSite.index_title

    The text to put at the top of the admin index page (a string). By default,
    this is "Site administration".

.. attribute:: AdminSite.index_template

    Path to a custom template that will be used by the admin site main index
    view.

.. attribute:: AdminSite.app_index_template

    Path to a custom template that will be used by the admin site app index view.

.. attribute:: AdminSite.login_template

    Path to a custom template that will be used by the admin site login view.

.. attribute:: AdminSite.login_form

    Subclass of :class:`~django.contrib.auth.forms.AuthenticationForm` that
    will be used by the admin site login view.

.. attribute:: AdminSite.logout_template

    Path to a custom template that will be used by the admin site logout view.

.. attribute:: AdminSite.password_change_template

    Path to a custom template that will be used by the admin site password
    change view.

.. attribute:: AdminSite.password_change_done_template

    Path to a custom template that will be used by the admin site password
    change done view.

``AdminSite`` methods
---------------------

.. method:: AdminSite.each_context(request)

    Returns a dictionary of variables to put in the template context for
    every page in the admin site.

    Includes the following variables and values by default:

    * ``site_header``: :attr:`AdminSite.site_header`
    * ``site_title``: :attr:`AdminSite.site_title`
    * ``site_url``: :attr:`AdminSite.site_url`
    * ``has_permission``: :meth:`AdminSite.has_permission`

    .. versionchanged:: 1.8

        The ``request`` argument and the ``has_permission`` variable were added.

.. method:: AdminSite.has_permission(request)

    Returns ``True`` if the user for the given ``HttpRequest`` has permission
    to view at least one page in the admin site. Defaults to requiring both
    :attr:`User.is_active <django.contrib.auth.models.User.is_active>` and
    :attr:`User.is_staff <django.contrib.auth.models.User.is_staff>` to be
    ``True``.

Hooking ``AdminSite`` instances into your URLconf
-------------------------------------------------

The last step in setting up the Django admin is to hook your ``AdminSite``
instance into your URLconf. Do this by pointing a given URL at the
``AdminSite.urls`` method.

In this example, we register the default ``AdminSite`` instance
``django.contrib.admin.site`` at the URL ``/admin/`` ::

    # urls.py
    from django.conf.urls import include, url
    from django.contrib import admin

    urlpatterns = [
        url(r'^admin/', include(admin.site.urls)),
    ]

.. _customizing-adminsite:

Customizing the :class:`AdminSite` class
----------------------------------------

If you'd like to set up your own admin site with custom behavior, you're free
to subclass ``AdminSite`` and override or add anything you like. Then, simply
create an instance of your ``AdminSite`` subclass (the same way you'd
instantiate any other Python class) and register your models and
``ModelAdmin`` subclasses with it instead of with the default site. Finally,
update :file:`myproject/urls.py` to reference your :class:`AdminSite` subclass.

.. snippet::
    :filename: myapp/admin.py

    from django.contrib.admin import AdminSite

    from .models import MyModel

    class MyAdminSite(AdminSite):
        site_header = 'Monty Python administration'

    admin_site = MyAdminSite(name='myadmin')
    admin_site.register(MyModel)


.. snippet::
    :filename: myproject/urls.py

    from django.conf.urls import include, url

    from myapp.admin import admin_site

    urlpatterns = [
        url(r'^myadmin/', include(admin_site.urls)),
    ]

Note that you may not want autodiscovery of ``admin`` modules when using your
own ``AdminSite`` instance since you will likely be importing all the per-app
``admin`` modules in your ``myproject.admin`` module. This means you need to
put ``'django.contrib.admin.apps.SimpleAdminConfig'`` instead of
``'django.contrib.admin'`` in your :setting:`INSTALLED_APPS` setting.

.. _multiple-admin-sites:

Multiple admin sites in the same URLconf
----------------------------------------

It's easy to create multiple instances of the admin site on the same
Django-powered Web site. Just create multiple instances of ``AdminSite`` and
root each one at a different URL.

In this example, the URLs ``/basic-admin/`` and ``/advanced-admin/`` feature
separate versions of the admin site -- using the ``AdminSite`` instances
``myproject.admin.basic_site`` and ``myproject.admin.advanced_site``,
respectively::

    # urls.py
    from django.conf.urls import include, url
    from myproject.admin import basic_site, advanced_site

    urlpatterns = [
        url(r'^basic-admin/', include(basic_site.urls)),
        url(r'^advanced-admin/', include(advanced_site.urls)),
    ]

``AdminSite`` instances take a single argument to their constructor, their
name, which can be anything you like. This argument becomes the prefix to the
URL names for the purposes of :ref:`reversing them<admin-reverse-urls>`. This
is only necessary if you are using more than one ``AdminSite``.

Adding views to admin sites
---------------------------

Just like :class:`ModelAdmin`, :class:`AdminSite` provides a
:meth:`~django.contrib.admin.ModelAdmin.get_urls()` method
that can be overridden to define additional views for the site. To add
a new view to your admin site, extend the base
:meth:`~django.contrib.admin.ModelAdmin.get_urls()` method to include
a pattern for your new view.

.. note::

    Any view you render that uses the admin templates, or extends the base
    admin template, should set ``request.current_app`` before rendering the
    template. It should be set to either ``self.name`` if your view is on an
    ``AdminSite`` or ``self.admin_site.name`` if your view is on a
    ``ModelAdmin``.

    .. versionchanged:: 1.8

       In previous versions of Django, you had to provide the ``current_app``
       argument to :class:`~django.template.RequestContext` or
       :class:`~django.template.Context` when rendering the template.

.. _auth_password_reset:

Adding a password-reset feature
-------------------------------

You can add a password-reset feature to the admin site by adding a few lines to
your URLconf. Specifically, add these four patterns::

    from django.contrib.auth import views as auth_views

    url(r'^admin/password_reset/$', auth_views.password_reset, name='admin_password_reset'),
    url(r'^admin/password_reset/done/$', auth_views.password_reset_done, name='password_reset_done'),
    url(r'^reset/(?P<uidb64>[0-9A-Za-z_\-]+)/(?P<token>.+)/$', auth_views.password_reset_confirm, name='password_reset_confirm'),
    url(r'^reset/done/$', auth_views.password_reset_complete, name='password_reset_complete'),

(This assumes you've added the admin at ``admin/`` and requires that you put
the URLs starting with ``^admin/`` before the line that includes the admin app
itself).

The presence of the ``admin_password_reset`` named URL will cause a "forgotten
your password?" link to appear on the default admin log-in page under the
password box.

.. _admin-reverse-urls:

Reversing admin URLs
====================

When an :class:`AdminSite` is deployed, the views provided by that site are
accessible using Django's :ref:`URL reversing system <naming-url-patterns>`.

The :class:`AdminSite` provides the following named URL patterns:

=========================  ========================  ==================================
Page                       URL name                  Parameters
=========================  ========================  ==================================
Index                      ``index``
Logout                     ``logout``
Password change            ``password_change``
Password change done       ``password_change_done``
i18n JavaScript            ``jsi18n``
Application index page     ``app_list``              ``app_label``
Redirect to object's page  ``view_on_site``          ``content_type_id``, ``object_id``
=========================  ========================  ==================================

Each :class:`ModelAdmin` instance provides an additional set of named URLs:

======================  ===============================================   =============
Page                    URL name                                          Parameters
======================  ===============================================   =============
Changelist              ``{{ app_label }}_{{ model_name }}_changelist``
Add                     ``{{ app_label }}_{{ model_name }}_add``
History                 ``{{ app_label }}_{{ model_name }}_history``      ``object_id``
Delete                  ``{{ app_label }}_{{ model_name }}_delete``       ``object_id``
Change                  ``{{ app_label }}_{{ model_name }}_change``       ``object_id``
======================  ===============================================   =============

These named URLs are registered with the application namespace ``admin``, and
with an instance namespace corresponding to the name of the Site instance.

So - if you wanted to get a reference to the Change view for a particular
``Choice`` object (from the polls application) in the default admin, you would
call::

    >>> from django.core import urlresolvers
    >>> c = Choice.objects.get(...)
    >>> change_url = urlresolvers.reverse('admin:polls_choice_change', args=(c.id,))

This will find the first registered instance of the admin application
(whatever the instance name), and resolve to the view for changing
``poll.Choice`` instances in that instance.

If you want to find a URL in a specific admin instance, provide the name of
that instance as a ``current_app`` hint to the reverse call. For example,
if you specifically wanted the admin view from the admin instance named
``custom``, you would need to call::

    >>> change_url = urlresolvers.reverse('admin:polls_choice_change',
    ...                                   args=(c.id,), current_app='custom')

For more details, see the documentation on :ref:`reversing namespaced URLs
<topics-http-reversing-url-namespaces>`.

To allow easier reversing of the admin urls in templates, Django provides an
``admin_urlname`` filter which takes an action as argument:

.. code-block:: html+django

    {% load admin_urls %}
    <a href="{% url opts|admin_urlname:'add' %}">Add user</a>
    <a href="{% url opts|admin_urlname:'delete' user.pk %}">Delete this user</a>

The action in the examples above match the last part of the URL names for
:class:`ModelAdmin` instances described above. The ``opts`` variable can be any
object which has an ``app_label`` and ``model_name`` attributes and is usually
supplied by the admin views for the current model.

.. currentmodule:: django.contrib.admin.views.decorators

The ``staff_member_required`` decorator
=======================================

.. function:: staff_member_required([redirect_field_name=REDIRECT_FIELD_NAME, login_url='admin:login'])

    This decorator is used on the admin views that require authorization. A
    view decorated with this function will having the following behavior:

    * If the user is logged in, is a staff member (``User.is_staff=True``), and
      is active (``User.is_active=True``), execute the view normally.

    * Otherwise, the request will be redirected to the URL specified by the
      ``login_url`` parameter, with the originally requested path in a query
      string variable specified by ``redirect_field_name``. For example:
      ``/admin/login/?next=/admin/polls/question/3/``.

    Example usage::

        from django.contrib.admin.views.decorators import staff_member_required

        @staff_member_required
        def my_view(request):
            ...