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1 =====================
2 The Django admin site
3 =====================
4
5 One of the most powerful parts of Django is the automatic admin interface. It
6 reads metadata in your model to provide a powerful and production-ready
7 interface that content producers can immediately use to start adding content to
8 the site. In this document, we discuss how to activate, use and customize
9 Django's admin interface.
10
11 .. admonition:: Note
12
13     The admin site has been refactored significantly since Django 0.96. This
14     document describes the newest version of the admin site, which allows for
15     much richer customization. If you follow the development of Django itself,
16     you may have heard this described as "newforms-admin."
17
18 Overview
19 ========
20
21 There are five steps in activating the Django admin site:
22
23     1. Add ``django.contrib.admin`` to your ``INSTALLED_APPS`` setting.
24
25     2. Determine which of your application's models should be editable in the
26        admin interface.
27
28     3. For each of those models, optionally create a ``ModelAdmin`` class that
29        encapsulates the customized admin functionality and options for that
30        particular model.
31
32     4. Instantiate an ``AdminSite`` and tell it about each of your models and
33        ``ModelAdmin`` classes.
34
35     5. Hook the ``AdminSite`` instance into your URLconf.
36
37 ``ModelAdmin`` objects
38 ======================
39
40 The ``ModelAdmin`` class is the representation of a model in the admin
41 interface. These are stored in a file named ``admin.py`` in your application.
42 Let's take a look at a very simple example the ``ModelAdmin``::
43
44     from django.contrib import admin
45     from myproject.myapp.models import Author
46
47     class AuthorAdmin(admin.ModelAdmin):
48         pass
49     admin.site.register(Author, AuthorAdmin)
50
51 ``ModelAdmin`` Options
52 ----------------------
53
54 The ``ModelAdmin`` is very flexible. It has several options for dealing with
55 customizing the interface. All options are defined on the ``ModelAdmin``
56 subclass::
57
58     class AuthorAdmin(admin.ModelAdmin):
59         date_hierarchy = 'pub_date'
60
61 ``date_hierarchy``
62 ~~~~~~~~~~~~~~~~~~
63
64 Set ``date_hierarchy`` to the name of a ``DateField`` or ``DateTimeField`` in
65 your model, and the change list page will include a date-based drilldown
66 navigation by that field.
67
68 Example::
69
70     date_hierarchy = 'pub_date'
71
72 ``form``
73 ~~~~~~~~
74
75 The default ``forms.ModelForm`` class used to generate the form on the
76 add/change pages for models. You can easily change this to your own
77 ``ModelForm`` to override the default form behavior of the add/change pages.
78
79 ``fieldsets``
80 ~~~~~~~~~~~~~
81
82 Set ``fieldsets`` to control the layout of admin "add" and "change" pages.
83
84 ``fieldsets`` is a list of two-tuples, in which each two-tuple represents a
85 ``<fieldset>`` on the admin form page. (A ``<fieldset>`` is a "section" of the
86 form.)
87
88 The two-tuples are in the format ``(name, field_options)``, where ``name`` is a
89 string representing the title of the fieldset and ``field_options`` is a
90 dictionary of information about the fieldset, including a list of fields to be
91 displayed in it.
92
93 A full example, taken from the ``django.contrib.flatpages.FlatPage`` model::
94
95     class FlatPageAdmin(admin.ModelAdmin):
96         fieldsets = (
97             (None, {
98                 'fields': ('url', 'title', 'content', 'sites')
99             }),
100             ('Advanced options', {
101                 'classes': ('collapse',),
102                 'fields': ('enable_comments', 'registration_required', 'template_name')
103             }),
104         )
105
106 This results in an admin page that looks like:
107
108     .. image:: http://media.djangoproject.com/img/doc/flatfiles_admin.png
109
110 If ``fieldsets`` isn't given, Django will default to displaying each field
111 that isn't an ``AutoField`` and has ``editable=True``, in a single fieldset,
112 in the same order as the fields are defined in the model.
113
114 The ``field_options`` dictionary can have the following keys:
115
116 ``fields``
117     A tuple of field names to display in this fieldset. This key is required.
118
119     Example::
120
121         {
122         'fields': ('first_name', 'last_name', 'address', 'city', 'state'),
123         }
124
125     To display multiple fields on the same line, wrap those fields in their own
126     tuple. In this example, the ``first_name`` and ``last_name`` fields will
127     display on the same line::
128
129         {
130         'fields': (('first_name', 'last_name'), 'address', 'city', 'state'),
131         }
132
133 ``classes``
134     A list containing extra CSS classes to apply to the fieldset.
135
136     Example::
137
138         {
139         'classes': ['wide', 'extrapretty'],
140         }
141
142     Two useful classes defined by the default admin-site stylesheet are
143     ``collapse`` and ``wide``. Fieldsets with the ``collapse`` style will be
144     initially collapsed in the admin and replaced with a small "click to expand"
145     link. Fieldsets with the ``wide`` style will be given extra horizontal space.
146
147 ``description``
148     A string of optional extra text to be displayed at the top of each fieldset,
149     under the heading of the fieldset.
150
151     Note that this value is *not* HTML-escaped when it's displayed in
152     the admin interface. This lets you include HTML if you so desire.
153     Alternatively you can use plain text and
154     ``django.utils.html.escape()`` to escape any HTML special
155     characters.
156
157 ``fields``
158 ~~~~~~~~~~
159
160 Use this option as an alternative to ``fieldsets`` if the layout does not
161 matter and if you want to only show a subset of the available fields in the
162 form. For example, you could define a simpler version of the admin form for
163 the ``django.contrib.flatpages.FlatPage`` model as follows::
164
165     class FlatPageAdmin(admin.ModelAdmin):
166         fields = ('url', 'title', 'content')
167
168 In the above example, only the fields 'url', 'title' and 'content' will be
169 displayed, sequencially, in the form.
170
171 .. admonition:: Note
172
173     This ``fields`` option should not be confused with the ``fields``
174     dictionary key that is within the ``fieldsets`` option, as described in
175     the previous section.
176
177 ``filter_horizontal``
178 ~~~~~~~~~~~~~~~~~~~~~
179
180 Use a nifty unobtrusive JavaScript "filter" interface instead of the
181 usability-challenged ``<select multiple>`` in the admin form. The value is a
182 list of fields that should be displayed as a horizontal filter interface. See
183 ``filter_vertical`` to use a vertical interface.
184
185 ``filter_vertical``
186 ~~~~~~~~~~~~~~~~~~~
187
188 Same as ``filter_horizontal``, but is a vertical display of the filter
189 interface.
190
191 ``list_display``
192 ~~~~~~~~~~~~~~~~
193
194 Set ``list_display`` to control which fields are displayed on the change list
195 page of the admin.
196
197 Example::
198
199     list_display = ('first_name', 'last_name')
200
201 If you don't set ``list_display``, the admin site will display a single column
202 that displays the ``__unicode__()`` representation of each object.
203
204 A few special cases to note about ``list_display``:
205
206     * If the field is a ``ForeignKey``, Django will display the
207       ``__unicode__()`` of the related object.
208
209     * ``ManyToManyField`` fields aren't supported, because that would entail
210       executing a separate SQL statement for each row in the table. If you
211       want to do this nonetheless, give your model a custom method, and add
212       that method's name to ``list_display``. (See below for more on custom
213       methods in ``list_display``.)
214
215     * If the field is a ``BooleanField`` or ``NullBooleanField``, Django will
216       display a pretty "on" or "off" icon instead of ``True`` or ``False``.
217
218     * If the string given is a method of the model, Django will call it and
219       display the output. This method should have a ``short_description``
220       function attribute, for use as the header for the field.
221
222       Here's a full example model::
223
224           class Person(models.Model):
225               name = models.CharField(max_length=50)
226               birthday = models.DateField()
227
228               def decade_born_in(self):
229                   return self.birthday.strftime('%Y')[:3] + "0's"
230               decade_born_in.short_description = 'Birth decade'
231
232           class PersonAdmin(admin.ModelAdmin):
233               list_display = ('name', 'decade_born_in')
234
235     * If the string given is a method of the model, Django will HTML-escape the
236       output by default. If you'd rather not escape the output of the method,
237       give the method an ``allow_tags`` attribute whose value is ``True``.
238
239       Here's a full example model::
240
241           class Person(models.Model):
242               first_name = models.CharField(max_length=50)
243               last_name = models.CharField(max_length=50)
244               color_code = models.CharField(max_length=6)
245
246               def colored_name(self):
247                   return '<span style="color: #%s;">%s %s</span>' % (self.color_code, self.first_name, self.last_name)
248               colored_name.allow_tags = True
249
250           class PersonAdmin(admin.ModelAdmin):
251               list_display = ('first_name', 'last_name', 'colored_name')
252
253     * If the string given is a method of the model that returns True or False
254       Django will display a pretty "on" or "off" icon if you give the method a
255       ``boolean`` attribute whose value is ``True``.
256
257       Here's a full example model::
258
259           class Person(models.Model):
260               first_name = models.CharField(max_length=50)
261               birthday = models.DateField()
262
263               def born_in_fifties(self):
264                   return self.birthday.strftime('%Y')[:3] == 5
265               born_in_fifties.boolean = True
266
267           class PersonAdmin(admin.ModelAdmin):
268               list_display = ('name', 'born_in_fifties')
269
270
271     * The ``__str__()`` and ``__unicode__()`` methods are just as valid in
272       ``list_display`` as any other model method, so it's perfectly OK to do
273       this::
274
275           list_display = ('__unicode__', 'some_other_field')
276
277     * Usually, elements of ``list_display`` that aren't actual database fields
278       can't be used in sorting (because Django does all the sorting at the
279       database level).
280
281       However, if an element of ``list_display`` represents a certain database
282       field, you can indicate this fact by setting the ``admin_order_field``
283       attribute of the item.
284
285       For example::
286
287         class Person(models.Model):
288             first_name = models.CharField(max_length=50)
289             color_code = models.CharField(max_length=6)
290
291             def colored_first_name(self):
292                 return '<span style="color: #%s;">%s</span>' % (self.color_code, self.first_name)
293             colored_first_name.allow_tags = True
294             colored_first_name.admin_order_field = 'first_name'
295
296         class PersonAdmin(admin.ModelAdmin):
297             list_display = ('first_name', 'colored_first_name')
298
299       The above will tell Django to order by the ``first_name`` field when
300       trying to sort by ``colored_first_name`` in the admin.
301
302 ``list_display_links``
303 ~~~~~~~~~~~~~~~~~~~~~~
304
305 Set ``list_display_links`` to control which fields in ``list_display`` should
306 be linked to the "change" page for an object.
307
308 By default, the change list page will link the first column -- the first field
309 specified in ``list_display`` -- to the change page for each item. But
310 ``list_display_links`` lets you change which columns are linked. Set
311 ``list_display_links`` to a list or tuple of field names (in the same format as
312 ``list_display``) to link.
313
314 ``list_display_links`` can specify one or many field names. As long as the
315 field names appear in ``list_display``, Django doesn't care how many (or how
316 few) fields are linked. The only requirement is: If you want to use
317 ``list_display_links``, you must define ``list_display``.
318
319 In this example, the ``first_name`` and ``last_name`` fields will be linked on
320 the change list page::
321
322     class PersonAdmin(admin.ModelAdmin):
323         list_display = ('first_name', 'last_name', 'birthday')
324         list_display_links = ('first_name', 'last_name')
325
326 Finally, note that in order to use ``list_display_links``, you must define
327 ``list_display``, too.
328
329 ``list_filter``
330 ~~~~~~~~~~~~~~~
331
332 Set ``list_filter`` to activate filters in the right sidebar of the change list
333 page of the admin. This should be a list of field names, and each specified
334 field should be either a ``BooleanField``, ``CharField``, ``DateField``,
335 ``DateTimeField``, ``IntegerField`` or ``ForeignKey``.
336
337 This example, taken from the ``django.contrib.auth.models.User`` model, shows
338 how both ``list_display`` and ``list_filter`` work::
339
340     class UserAdmin(admin.ModelAdmin):
341         list_display = ('username', 'email', 'first_name', 'last_name', 'is_staff')
342         list_filter = ('is_staff', 'is_superuser')
343
344 The above code results in an admin change list page that looks like this:
345
346     .. image:: http://media.djangoproject.com/img/doc/users_changelist.png
347
348 (This example also has ``search_fields`` defined. See below.)
349
350 ``list_per_page``
351 ~~~~~~~~~~~~~~~~~
352
353 Set ``list_per_page`` to control how many items appear on each paginated admin
354 change list page. By default, this is set to ``100``.
355
356 ``list_select_related``
357 ~~~~~~~~~~~~~~~~~~~~~~~
358
359 Set ``list_select_related`` to tell Django to use ``select_related()`` in
360 retrieving the list of objects on the admin change list page. This can save you
361 a bunch of database queries.
362
363 The value should be either ``True`` or ``False``. Default is ``False``.
364
365 Note that Django will use ``select_related()``, regardless of this setting,
366 if one of the ``list_display`` fields is a ``ForeignKey``.
367
368 For more on ``select_related()``, see `the select_related() docs`_.
369
370 .. _the select_related() docs: ../db-api/#select-related
371
372 ``inlines``
373 ~~~~~~~~~~~
374
375 See ``InlineModelAdmin`` objects below.
376
377 ``ordering``
378 ~~~~~~~~~~~~
379
380 Set ``ordering`` to specify how objects on the admin change list page should be
381 ordered. This should be a list or tuple in the same format as a model's
382 ``ordering`` parameter.
383
384 If this isn't provided, the Django admin will use the model's default ordering.
385
386 .. admonition:: Note
387
388     Django will only honor the first element in the list/tuple; any others
389     will be ignored.
390
391 ``prepopulated_fields``
392 ~~~~~~~~~~~~~~~~~~~~~~~
393
394 Set ``prepopulated_fields`` to a dictionary mapping field names to the fields
395 it should prepopulate from::
396
397     class ArticleAdmin(admin.ModelAdmin):
398         prepopulated_fields = {"slug": ("title",)}
399
400 When set, the given fields will use a bit of JavaScript to populate from the
401 fields assigned. The main use for this functionality is to automatically
402 generate the value for ``SlugField`` fields from one or more other fields. The
403 generated value is produced by concatenating the values of the source fields,
404 and then by transforming that result into a valid slug (e.g. substituting
405 dashes for spaces).
406
407 ``prepopulated_fields`` doesn't accept ``DateTimeField``, ``ForeignKey``, nor
408 ``ManyToManyField`` fields.
409
410 ``radio_fields``
411 ~~~~~~~~~~~~~~~~
412
413 By default, Django's admin uses a select-box interface (<select>) for
414 fields that are ``ForeignKey`` or have ``choices`` set. If a field is present
415 in ``radio_fields``, Django will use a radio-button interface instead.
416 Assuming ``group`` is a ``ForeignKey`` on the ``Person`` model::
417
418     class PersonAdmin(admin.ModelAdmin):
419         radio_fields = {"group": admin.VERTICAL}
420
421 You have the choice of using ``HORIZONTAL`` or ``VERTICAL`` from the
422 ``django.contrib.admin`` module.
423
424 Don't include a field in ``radio_fields`` unless it's a ``ForeignKey`` or has
425 ``choices`` set.
426
427 ``raw_id_fields``
428 ~~~~~~~~~~~~~~~~~
429
430 By default, Django's admin uses a select-box interface (<select>) for
431 fields that are ``ForeignKey``. Sometimes you don't want to incur the
432 overhead of having to select all the related instances to display in the
433 drop-down.
434
435 ``raw_id_fields`` is a list of fields you would like to change
436 into a ``Input`` widget for either a ``ForeignKey`` or ``ManyToManyField``::
437
438     class ArticleAdmin(admin.ModelAdmin):
439         raw_id_fields = ("newspaper",)
440
441 ``save_as``
442 ~~~~~~~~~~~
443
444 Set ``save_as`` to enable a "save as" feature on admin change forms.
445
446 Normally, objects have three save options: "Save", "Save and continue editing"
447 and "Save and add another". If ``save_as`` is ``True``, "Save and add another"
448 will be replaced by a "Save as" button.
449
450 "Save as" means the object will be saved as a new object (with a new ID),
451 rather than the old object.
452
453 By default, ``save_as`` is set to ``False``.
454
455 ``save_on_top``
456 ~~~~~~~~~~~~~~~
457
458 Set ``save_on_top`` to add save buttons across the top of your admin change
459 forms.
460
461 Normally, the save buttons appear only at the bottom of the forms. If you set
462 ``save_on_top``, the buttons will appear both on the top and the bottom.
463
464 By default, ``save_on_top`` is set to ``False``.
465
466 ``search_fields``
467 ~~~~~~~~~~~~~~~~~
468
469 Set ``search_fields`` to enable a search box on the admin change list page.
470 This should be set to a list of field names that will be searched whenever
471 somebody submits a search query in that text box.
472
473 These fields should be some kind of text field, such as ``CharField`` or
474 ``TextField``. You can also perform a related lookup on a ``ForeignKey`` with
475 the lookup API "follow" notation::
476
477     search_fields = ['foreign_key__related_fieldname']
478
479 When somebody does a search in the admin search box, Django splits the search
480 query into words and returns all objects that contain each of the words, case
481 insensitive, where each word must be in at least one of ``search_fields``. For
482 example, if ``search_fields`` is set to ``['first_name', 'last_name']`` and a
483 user searches for ``john lennon``, Django will do the equivalent of this SQL
484 ``WHERE`` clause::
485
486     WHERE (first_name ILIKE '%john%' OR last_name ILIKE '%john%')
487     AND (first_name ILIKE '%lennon%' OR last_name ILIKE '%lennon%')
488
489 For faster and/or more restrictive searches, prefix the field name
490 with an operator:
491
492 ``^``
493     Matches the beginning of the field. For example, if ``search_fields`` is
494     set to ``['^first_name', '^last_name']`` and a user searches for
495     ``john lennon``, Django will do the equivalent of this SQL ``WHERE``
496     clause::
497
498         WHERE (first_name ILIKE 'john%' OR last_name ILIKE 'john%')
499         AND (first_name ILIKE 'lennon%' OR last_name ILIKE 'lennon%')
500
501     This query is more efficient than the normal ``'%john%'`` query, because
502     the database only needs to check the beginning of a column's data, rather
503     than seeking through the entire column's data. Plus, if the column has an
504     index on it, some databases may be able to use the index for this query,
505     even though it's a ``LIKE`` query.
506
507 ``=``
508     Matches exactly, case-insensitive. For example, if
509     ``search_fields`` is set to ``['=first_name', '=last_name']`` and
510     a user searches for ``john lennon``, Django will do the equivalent
511     of this SQL ``WHERE`` clause::
512
513         WHERE (first_name ILIKE 'john' OR last_name ILIKE 'john')
514         AND (first_name ILIKE 'lennon' OR last_name ILIKE 'lennon')
515
516     Note that the query input is split by spaces, so, following this example,
517     it's currently not possible to search for all records in which
518     ``first_name`` is exactly ``'john winston'`` (containing a space).
519
520 ``@``
521     Performs a full-text match. This is like the default search method but uses
522     an index. Currently this is only available for MySQL.
523
524 ``ModelAdmin`` media definitions
525 --------------------------------
526
527 There are times where you would like add a bit of CSS and/or JavaScript to
528 the add/change views. This can be accomplished by using a Media inner class
529 on your ``ModelAdmin``::
530
531     class ArticleAdmin(admin.ModelAdmin):
532         class Media:
533             css = {
534                 "all": ("my_styles.css",)
535             }
536             js = ("my_code.js",)
537
538 Keep in mind that this will be prepended with ``MEDIA_URL``. The same rules
539 apply as `regular media definitions on forms`_.
540
541 .. _regular media definitions on forms: ../forms/#media
542
543 Adding custom validation to the admin
544 -------------------------------------
545
546 Adding custom validation of data in the admin is quite easy. The automatic
547 admin interfaces reuses the Django `forms`_ module. The ``ModelAdmin`` class
548 gives you the ability define your own form::
549
550     class ArticleAdmin(admin.ModelAdmin):
551         form = MyArticleAdminForm
552
553 ``MyArticleAdminForm`` can be defined anywhere as long as you import where
554 needed. Now within your form you can add your own custom validation for
555 any field::
556    
557     class MyArticleAdminForm(forms.ModelForm):
558         def clean_name(self):
559             # do something that validates your data
560             return self.cleaned_data["name"]
561
562 It is important you use a ``ModelForm`` here otherwise things can break. See
563 the `forms`_ documentation on `custom validation`_ for more information.
564
565 .. _forms: ../forms/
566 .. _custom validation: ../forms/#custom-form-and-field-validation
567
568 ``InlineModelAdmin`` objects
569 ============================
570
571 The admin interface has the ability to edit models on the same page as a
572 parent model. These are called inlines. You can add them to a model by
573 specifying them in a ``ModelAdmin.inlines`` attribute::
574
575     class BookInline(admin.TabularInline):
576         model = Book
577
578     class AuthorAdmin(admin.ModelAdmin):
579         inlines = [
580             BookInline,
581         ]
582
583 Django provides two subclasses of ``InlineModelAdmin`` and they are:
584
585     * ``TabularInline``
586     * ``StackedInline``
587
588 The difference between these two is merely the template used to render them.
589
590 ``InlineModelAdmin`` options
591 -----------------------------
592
593 The ``InlineModelAdmin`` class is a subclass of ``ModelAdmin`` so it inherits
594 all the same functionality as well as some of its own:
595
596 ``model``
597 ~~~~~~~~~
598
599 The model in which the inline is using. This is required.
600
601 ``fk_name``
602 ~~~~~~~~~~~
603
604 The name of the foreign key on the model. In most cases this will be dealt
605 with automatically, but ``fk_name`` must be specified explicitly if there are
606 more than one foreign key to the same parent model.
607
608 ``formset``
609 ~~~~~~~~~~~
610
611 This defaults to ``BaseInlineFormset``. Using your own formset can give you
612 many possibilities of customization. Inlines are built around
613 `model formsets`_.
614
615 .. _model formsets: ../modelforms/#model-formsets
616
617 ``form``
618 ~~~~~~~~
619
620 The value for ``form`` is inherited from ``ModelAdmin``. This is what is
621 passed through to ``formset_factory`` when creating the formset for this
622 inline.
623
624 ``extra``
625 ~~~~~~~~~
626
627 This controls the number of extra forms the formset will display in addition
628 to the initial forms. See the `formsets documentation`_ for more information.
629
630 .. _formsets documentation: ../forms/#formsets
631
632 ``max_num``
633 ~~~~~~~~~~~
634
635 This controls the maximum number of forms to show in the inline. This doesn't
636 directly corrolate to the number of objects, but can if the value is small
637 enough. See `max_num in formsets`_ for more information.
638
639 .. _max_num in formsets: ../modelforms/#limiting-the-number-of-objects-editable
640
641 ``raw_id_fields``
642 ~~~~~~~~~~~~~~~~~
643
644 By default, Django's admin uses a select-box interface (<select>) for
645 fields that are ``ForeignKey``. Sometimes you don't want to incur the
646 overhead of having to select all the related instances to display in the
647 drop-down.
648
649 ``raw_id_fields`` is a list of fields you would like to change
650 into a ``Input`` widget for either a ``ForeignKey`` or ``ManyToManyField``::
651
652     class BookInline(admin.TabularInline):
653         model = Book
654         raw_id_fields = ("pages",)
655
656 ``template``
657 ~~~~~~~~~~~~
658
659 The template used to render the inline on the page.
660
661 ``verbose_name``
662 ~~~~~~~~~~~~~~~~
663
664 An override to the ``verbose_name`` found in the model's inner ``Meta`` class.
665
666 ``verbose_name_plural``
667 ~~~~~~~~~~~~~~~~~~~~~~~
668
669 An override to the ``verbose_name_plural`` found in the model's inner ``Meta``
670 class.
671
672 Working with a model with two or more foreign keys to the same parent model
673 ---------------------------------------------------------------------------
674
675 It is sometimes possible to have more than one foreign key to the same model.
676 Take this model for instance::
677
678     class Friendship(models.Model):
679         to_person = models.ForeignKey(Person, related_name="friends")
680         from_person = models.ForeignKey(Person, related_name="from_friends")
681
682 If you wanted to display an inline on the ``Person`` admin add/change pages
683 you need to explicitly define the foreign key since it is unable to do so
684 automatically::
685
686     class FriendshipInline(admin.TabularInline):
687         model = Friendship
688         fk_name = "to_person"
689
690     class PersonAdmin(admin.ModelAdmin):
691         inlines = [
692             FriendshipInline,
693         ]
694
695 Working with Many-to-Many Intermediary Models
696 ----------------------------------------------
697
698 By default, admin widgets for many-to-many relations will be displayed inline
699 on whichever model contains the actual reference to the ``ManyToManyField``.
700 However, when you specify an intermediary model using the ``through``
701 argument to a ``ManyToManyField``, the admin will not display a widget by
702 default. This is because each instance of that intermediary model requires
703 more information than could be displayed in a single widget, and the layout
704 required for multiple widgets will vary depending on the intermediate model.
705
706 However, we still want to be able to edit that information inline. Fortunately,
707 this is easy to do with inline admin models. Suppose we have the following
708 models::
709
710     class Person(models.Model):
711         name = models.CharField(max_length=128)
712    
713     class Group(models.Model):
714         name = models.CharField(max_length=128)
715         members = models.ManyToManyField(Person, through='Membership')
716
717     class Membership(models.Model):
718         person = models.ForeignKey(Person)
719         group = models.ForeignKey(Group)
720         date_joined = models.DateField()
721         invite_reason = models.CharField(max_length=64)
722
723 The first step in displaying this intermediate model in the admin is to
724 define an inline class for the ``Membership`` model::
725
726     class MembershipInline(admin.TabularInline):
727         model = Membership
728         extra = 1
729
730 This simple example uses the default ``InlineModelAdmin`` values for the
731 ``Membership`` model, and limits the extra add forms to one. This could be
732 customized using any of the options available to ``InlineModelAdmin`` classes.
733
734 Now create admin views for the ``Person`` and ``Group`` models::
735
736     class PersonAdmin(admin.ModelAdmin):
737         inlines = (MembershipInline,)
738
739     class GroupAdmin(admin.ModelAdmin):
740         inlines = (MembershipInline,)
741
742 Finally, register your ``Person`` and ``Group`` models with the admin site::
743    
744     admin.site.register(Person, PersonAdmin)
745     admin.site.register(Group, GroupAdmin)
746
747 Now your admin site is set up to edit ``Membership`` objects inline from
748 either the ``Person`` or the ``Group`` detail pages.
749
750 ``AdminSite`` objects
751 =====================
752
753 Hooking ``AdminSite`` instances into your URLconf
754 -------------------------------------------------
755
756 The last step in setting up the Django admin is to hook your ``AdminSite``
757 instance into your URLconf. Do this by pointing a given URL at the
758 ``AdminSite.root`` method.
759
760 In this example, we register the default ``AdminSite`` instance
761 ``django.contrib.admin.site`` at the URL ``/admin/`` ::
762
763     # urls.py
764     from django.conf.urls.defaults import *
765     from django.contrib import admin
766
767     admin.autodiscover()
768
769     urlpatterns = patterns('',
770         ('^admin/(.*)', admin.site.root),
771     )
772
773 Above we used ``admin.autodiscover()`` to automatically load the
774 ``INSTALLED_APPS`` admin.py modules.
775
776 In this example, we register the ``AdminSite`` instance
777 ``myproject.admin.admin_site`` at the URL ``/myadmin/`` ::
778
779     # urls.py
780     from django.conf.urls.defaults import *
781     from myproject.admin import admin_site
782
783     urlpatterns = patterns('',
784         ('^myadmin/(.*)', admin_site.root),
785     )
786
787 There is really no need to use autodiscover when using your own ``AdminSite``
788 instance since you will likely be importing all the per-app admin.py modules
789 in your ``myproject.admin`` module.
790
791 Note that the regular expression in the URLpattern *must* group everything in
792 the URL that comes after the URL root -- hence the ``(.*)`` in these examples.
793
794 Multiple admin sites in the same URLconf
795 ----------------------------------------
796
797 It's easy to create multiple instances of the admin site on the same
798 Django-powered Web site. Just create multiple instances of ``AdminSite`` and
799 root each one at a different URL.
800
801 In this example, the URLs ``/basic-admin/`` and ``/advanced-admin/`` feature
802 separate versions of the admin site -- using the ``AdminSite`` instances
803 ``myproject.admin.basic_site`` and ``myproject.admin.advanced_site``,
804 respectively::
805
806     # urls.py
807     from django.conf.urls.defaults import *
808     from myproject.admin import basic_site, advanced_site
809
810     urlpatterns = patterns('',
811         ('^basic-admin/(.*)', basic_site.root),
812         ('^advanced-admin/(.*)', advanced_site.root),
813     )
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