root/django/branches/newforms-admin/docs/admin.txt

=====================
The Django 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.

.. admonition:: Note

    The admin site has been refactored significantly since Django 0.96. This
    document describes the newest version of the admin site, which allows for
    much richer customization. If you follow the development of Django itself,
    you may have heard this described as "newforms-admin."

Overview
========

There are four steps in activating the Django admin site:

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

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

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

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

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

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

    from django.contrib import admin
    from myproject.myapp.models import Author
    
    class AuthorAdmin(admin.ModelAdmin):
        pass
    admin.site.register(Author, AuthorAdmin)

``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::

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

``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'

``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 ``django.contrib.flatpages.FlatPage`` model::
    
    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:: http://media.djangoproject.com/img/doc/flatfiles_admin.png

If ``fieldsets`` isn't given, 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'),
        }

    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'),
        }

``classes``
    A string containing extra CSS classes to apply to the fieldset.
    
    Example::
        
        {
        'classes': 'wide',
        }

    Apply multiple classes by separating them with spaces. 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. It's used verbatim, so you can use any HTML
    and you must escape any special HTML characters (such as ampersands) yourself.

``filter_horizontal``
~~~~~~~~~~~~~~~~~~~~~

Use a nifty unobtrusive Javascript "filter" interface instead of the
usability-challenged ``<select multiple>`` in the admin form. The value is a
list of fields that should be displayed as a horizontal filter interface. See
``filter_vertical`` to use a vertical interface.

``filter_vertical``
~~~~~~~~~~~~~~~~~~~

Same as ``filter_horizontal``, but is a vertical display of the filter
interface.

``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 ``__unicode__()`` representation of each object.

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

    * If the field is a ``ForeignKey``, Django will display the
      ``__unicode__()`` 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, Django will call it and
      display the output. This method should have a ``short_description``
      function attribute, for use as the header for the field.

      Here's a full example model::
          
          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')

    * If the string given is a method of the model, 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``.

      Here's a full example model::

          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 '<span style="color: #%s;">%s %s</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 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::

          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] == 5
              born_in_fifties.boolean = True
          
          class PersonAdmin(admin.ModelAdmin):
              list_display = ('name', 'born_in_fifties')


    * The ``__str__()`` and ``__unicode__()`` methods are just as valid in
      ``list_display`` as any other model method, so it's perfectly OK to do
      this::

          list_display = ('__unicode__', '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::

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

            def colored_first_name(self):
                return '<span style="color: #%s;">%s</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.

``list_display_links``
~~~~~~~~~~~~~~~~~~~~~~

Set ``list_display_links`` to control which fields in ``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 which columns are linked. Set
``list_display_links`` to a list or tuple of field names (in the same format as
``list_display``) to link.

``list_display_links`` can specify one or many field names. As long as the
field names appear in ``list_display``, Django doesn't care how many (or how
few) fields are linked. The only requirement is: If you want to use
``list_display_links``, 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')

Finally, note that in order to use ``list_display_links``, you must define
``list_display``, too.

``list_filter``
~~~~~~~~~~~~~~~

Set ``list_filter`` to activate filters in the right sidebar of the change list
page of the admin. This should be a list of field names, and each specified
field should be either a ``BooleanField``, ``CharField``, ``DateField``,
``DateTimeField``, ``IntegerField`` or ``ForeignKey``.

This example, taken from the ``django.contrib.auth.models.User`` model, shows
how both ``list_display`` and ``list_filter`` work::

    class UserAdmin(admin.ModelAdmin):
        list_display = ('username', 'email', 'first_name', 'last_name', 'is_staff')
        list_filter = ('is_staff', 'is_superuser')

The above code results in an admin change list page that looks like this:

    .. image:: http://media.djangoproject.com/img/doc/users_changelist.png

(This example also has ``search_fields`` defined. See below.)

``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``.

``list_select_related``
~~~~~~~~~~~~~~~~~~~~~~~

Set ``list_select_related`` to tell Django to use ``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 ``True`` or ``False``. Default is ``False``.

Note that Django will use ``select_related()``, regardless of this setting,
if one of the ``list_display`` fields is a ``ForeignKey``.

For more on ``select_related()``, see `the select_related() docs`_.

.. _the select_related() docs: ../db-api/#select-related

``inlines``
~~~~~~~~~~~

See ``InlineModelAdmin`` objects below.

``ordering``
~~~~~~~~~~~~

Set ``ordering`` to specify how objects on the admin change list page should be
ordered. This should be a list or tuple in the same format as a model's
``ordering`` parameter.

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

``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.

``prepopulated_fields`` doesn't accept DateTimeFields, ForeignKeys nor
ManyToManyFields.

``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.

``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 the primary key.

``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``.

``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``.

``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`` with
the lookup API "follow" notation::

    search_fields = ['foreign_key__related_fieldname']

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.

``ModelAdmin`` media 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",)

Keep in mind that this will be prepended with ``MEDIA_URL``. The same rules
apply as `regular media definitions on forms`_.

.. _regular media definitions on forms: ../newforms/#media

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

The admin interface has the ability to edit models on the same page as a
parent model. These are called inlines. You can add them a model being
specifing them in a ``ModelAdmin.inlines`` attribute::

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

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

    * ``TabularInline``
    * ``StackedInline``

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

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

The ``InlineModelAdmin`` class is a subclass of ``ModelAdmin`` so it inherits
all the same functionality as well as some of its own:

``model``
~~~~~~~~~

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

``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.

``formset``
~~~~~~~~~~~

This defaults to ``BaseInlineFormset``. Using your own formset can give you
many possibilities of customization. Inlines are built around
`model formsets`_.

.. _model formsets: ../modelforms/#model-formsets

``form``
~~~~~~~~

The value for ``form`` is inherited from ``ModelAdmin``. This is what is
passed through to ``formset_factory`` when creating the formset for this
inline.

``extra``
~~~~~~~~~

This controls the number of extra forms the formset will display in addition
to the initial forms. See the `formsets documentation`_ for more information.

.. _formsets documentation: ../newforms/#formsets

``max_num``
~~~~~~~~~~~

This controls the maximum number of forms to show in the inline. This doesn't
directly corrolate to the number of objects, but can if the value is small
enough. See `max_num in formsets`_ for more information.

.. _max_num in formsets: ../modelforms/#limiting-the-number-of-objects-editable

``template``
~~~~~~~~~~~~

The template used to render the inline on the page.

``verbose_name``
~~~~~~~~~~~~~~~~

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

``verbose_name_plural``
~~~~~~~~~~~~~~~~~~~~~~~

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

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::

    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::

    class FriendshipInline(admin.TabularInline):
        model = Friendship
        fk_name = "to_person"
    
    class PersonAdmin(admin.ModelAdmin):
        inlines = [
            FriendshipInline,
        ]

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

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.root`` method.

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

    # urls.py
    from django.conf.urls.defaults import *
    from django.contrib import admin
    
    admin.autodiscover()

    urlpatterns = patterns('',
        ('^admin/(.*)', admin.site.root),
    )

Above we used ``admin.autodiscover()`` to automatically load the
``INSTALLED_APPS`` admin.py modules.

In this example, we register the ``AdminSite`` instance
``myproject.admin.admin_site`` at the URL ``/myadmin/`` ::

    # urls.py
    from django.conf.urls.defaults import *
    from myproject.admin import admin_site

    urlpatterns = patterns('',
        ('^myadmin/(.*)', admin_site.root),
    )

There is really no need to use autodiscover when using your own ``AdminSite``
instance since you will likely be importing all the per-app admin.py modules
in your ``myproject.admin`` module.

Note that the regular expression in the URLpattern *must* group everything in
the URL that comes after the URL root -- hence the ``(.*)`` in these examples.

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.defaults import *
    from myproject.admin import basic_site, advanced_site

    urlpatterns = patterns('',
        ('^basic-admin/(.*)', basic_site.root),
        ('^advanced-admin/(.*)', advanced_site.root),
    )