Fixed #13165 -- Added edit and delete links to admin foreign key widgets.

Thanks to Collin Anderson for the review and suggestions and Tim for the
final review.

django/contrib/admin/options.py

@@ -188,11 +188,16 @@ class BaseModelAdmin(six.with_metaclass(forms.MediaDefiningClass)):
             # OneToOneField with parent_link=True or a M2M intermediary.
             if formfield and db_field.name not in self.raw_id_fields:
                 related_modeladmin = self.admin_site._registry.get(db_field.rel.to)
-                can_add_related = bool(related_modeladmin and
-                    related_modeladmin.has_add_permission(request))
+                wrapper_kwargs = {}
+                if related_modeladmin:
+                    wrapper_kwargs.update(
+                        can_add_related=related_modeladmin.has_add_permission(request),
+                        can_change_related=related_modeladmin.has_change_permission(request),
+                        can_delete_related=related_modeladmin.has_delete_permission(request),
+                    )
                 formfield.widget = widgets.RelatedFieldWidgetWrapper(
-                    formfield.widget, db_field.rel, self.admin_site,
-                    can_add_related=can_add_related)
+                    formfield.widget, db_field.rel, self.admin_site, **wrapper_kwargs
+                )
 
             return formfield
 
@@ -703,17 +708,18 @@ class ModelAdmin(BaseModelAdmin):
         from django.contrib.admin.views.main import ChangeList
         return ChangeList
 
-    def get_object(self, request, object_id):
+    def get_object(self, request, object_id, from_field=None):
         """
-        Returns an instance matching the primary key provided. ``None``  is
-        returned if no match is found (or the object_id failed validation
-        against the primary key field).
+        Returns an instance matching the field and value provided, the primary
+        key is used if no field is provided. Returns ``None`` if no match is
+        found or the object_id fails validation.
         """
         queryset = self.get_queryset(request)
         model = queryset.model
+        field = model._meta.pk if from_field is None else model._meta.get_field(from_field)
         try:
-            object_id = model._meta.pk.to_python(object_id)
-            return queryset.get(pk=object_id)
+            object_id = field.to_python(object_id)
+            return queryset.get(**{field.name: object_id})
         except (model.DoesNotExist, ValidationError, ValueError):
             return None
 
@@ -1186,6 +1192,19 @@ class ModelAdmin(BaseModelAdmin):
         Determines the HttpResponse for the change_view stage.
         """
 
+        if IS_POPUP_VAR in request.POST:
+            to_field = request.POST.get(TO_FIELD_VAR)
+            attr = str(to_field) if to_field else obj._meta.pk.attname
+            # Retrieve the `object_id` from the resolved pattern arguments.
+            value = request.resolver_match.args[0]
+            new_value = obj.serializable_value(attr)
+            return SimpleTemplateResponse('admin/popup_response.html', {
+                'action': 'change',
+                'value': escape(value),
+                'obj': escapejs(obj),
+                'new_value': escape(new_value),
+            })
+
         opts = self.model._meta
         pk_value = obj._get_pk_val()
         preserved_filters = self.get_preserved_filters(request)
@@ -1324,17 +1343,23 @@ class ModelAdmin(BaseModelAdmin):
             self.message_user(request, msg, messages.WARNING)
             return None
 
-    def response_delete(self, request, obj_display):
+    def response_delete(self, request, obj_display, obj_id):
         """
         Determines the HttpResponse for the delete_view stage.
         """
 
         opts = self.model._meta
 
+        if IS_POPUP_VAR in request.POST:
+            return SimpleTemplateResponse('admin/popup_response.html', {
+                'action': 'delete',
+                'value': escape(obj_id),
+            })
+
         self.message_user(request,
             _('The %(name)s "%(obj)s" was deleted successfully.') % {
                 'name': force_text(opts.verbose_name),
-                'obj': force_text(obj_display)
+                'obj': force_text(obj_display),
             }, messages.SUCCESS)
 
         if self.has_change_permission(request, None):
@@ -1355,6 +1380,10 @@ class ModelAdmin(BaseModelAdmin):
         app_label = opts.app_label
 
         request.current_app = self.admin_site.name
+        context.update(
+            to_field_var=TO_FIELD_VAR,
+            is_popup_var=IS_POPUP_VAR,
+        )
 
         return TemplateResponse(request,
             self.delete_confirmation_template or [
@@ -1409,7 +1438,7 @@ class ModelAdmin(BaseModelAdmin):
             obj = None
 
         else:
-            obj = self.get_object(request, unquote(object_id))
+            obj = self.get_object(request, unquote(object_id), to_field)
 
             if not self.has_change_permission(request, obj):
                 raise PermissionDenied
@@ -1654,7 +1683,11 @@ class ModelAdmin(BaseModelAdmin):
         opts = self.model._meta
         app_label = opts.app_label
 
-        obj = self.get_object(request, unquote(object_id))
+        to_field = request.POST.get(TO_FIELD_VAR, request.GET.get(TO_FIELD_VAR))
+        if to_field and not self.to_field_allowed(request, to_field):
+            raise DisallowedModelAdminToField("The field %s cannot be referenced." % to_field)
+
+        obj = self.get_object(request, unquote(object_id), to_field)
 
         if not self.has_delete_permission(request, obj):
             raise PermissionDenied
@@ -1676,10 +1709,12 @@ class ModelAdmin(BaseModelAdmin):
             if perms_needed:
                 raise PermissionDenied
             obj_display = force_text(obj)
+            attr = str(to_field) if to_field else opts.pk.attname
+            obj_id = obj.serializable_value(attr)
             self.log_deletion(request, obj, obj_display)
             self.delete_model(request, obj)
 
-            return self.response_delete(request, obj_display)
+            return self.response_delete(request, obj_display, obj_id)
 
         object_name = force_text(opts.verbose_name)
 
@@ -1700,6 +1735,9 @@ class ModelAdmin(BaseModelAdmin):
             opts=opts,
             app_label=app_label,
             preserved_filters=self.get_preserved_filters(request),
+            is_popup=(IS_POPUP_VAR in request.POST or
+                      IS_POPUP_VAR in request.GET),
+            to_field=to_field,
         )
         context.update(extra_context or {})
 

django/contrib/admin/static/admin/css/widgets.css

@@ -576,3 +576,13 @@ ul.orderer li.deleted:hover, ul.orderer li.deleted a.selector:hover {
     font-size: 11px;
     border-top: 1px solid #ddd;
 }
+
+/* RELATED WIDGET WRAPPER */
+
+.related-widget-wrapper-link {
+    opacity: 0.3;
+}
+
+.related-widget-wrapper-link:link {
+    opacity: 1;
+}

django/contrib/admin/static/admin/js/admin/RelatedObjectLookups.js

@@ -56,11 +56,16 @@ function dismissRelatedLookupPopup(win, chosenId) {
     win.close();
 }
 
-function showAddAnotherPopup(triggeringLink) {
-    return showAdminPopup(triggeringLink, /^add_/);
+function showRelatedObjectPopup(triggeringLink) {
+    var name = triggeringLink.id.replace(/^(change|add|delete)_/, '');
+    name = id_to_windowname(name);
+    var href = triggeringLink.href;
+    var win = window.open(href, name, 'height=500,width=800,resizable=yes,scrollbars=yes');
+    win.focus();
+    return false;
 }
 
-function dismissAddAnotherPopup(win, newId, newRepr) {
+function dismissAddRelatedObjectPopup(win, newId, newRepr) {
     // newId and newRepr are expected to have previously been escaped by
     // django.utils.html.escape.
     newId = html_unescape(newId);
@@ -81,6 +86,8 @@ function dismissAddAnotherPopup(win, newId, newRepr) {
                 elem.value = newId;
             }
         }
+        // Trigger a change event to update related links if required.
+        django.jQuery(elem).trigger('change');
     } else {
         var toId = name + "_to";
         o = new Option(newRepr, newId);
@@ -89,3 +96,35 @@ function dismissAddAnotherPopup(win, newId, newRepr) {
     }
     win.close();
 }
+
+function dismissChangeRelatedObjectPopup(win, objId, newRepr, newId) {
+    objId = html_unescape(objId);
+    newRepr = html_unescape(newRepr);
+    var id = windowname_to_id(win.name).replace(/^edit_/, '');
+    var selectsSelector = interpolate('#%s, #%s_from, #%s_to', [id, id, id]);
+    var selects = django.jQuery(selectsSelector);
+    selects.find('option').each(function() {
+        if (this.value == objId) {
+            this.innerHTML = newRepr;
+            this.value = newId;
+        }
+    });
+    win.close();
+};
+
+function dismissDeleteRelatedObjectPopup(win, objId) {
+    objId = html_unescape(objId);
+    var id = windowname_to_id(win.name).replace(/^delete_/, '');
+    var selectsSelector = interpolate('#%s, #%s_from, #%s_to', [id, id, id]);
+    var selects = django.jQuery(selectsSelector);
+    selects.find('option').each(function() {
+        if (this.value == objId) {
+            django.jQuery(this).remove();
+        }
+    }).trigger('change');
+    win.close();
+};
+
+// Kept for backward compatibility
+showAddAnotherPopup = showRelatedObjectPopup;
+dismissAddAnotherPopup = dismissAddRelatedObjectPopup;

django/contrib/admin/static/admin/js/related-widget-wrapper.js

+django.jQuery(function($){
+    function updateLinks() {
+        var $this = $(this);
+        var siblings = $this.nextAll('.change-related, .delete-related');
+        if (!siblings.length) return;
+        var value = $this.val();
+        if (value) {
+            siblings.each(function(){
+                var elm = $(this);
+                elm.attr('href', elm.attr('data-href-template').replace('__fk__', value));
+            });
+        } else siblings.removeAttr('href');
+    }
+    var container = $(document);
+    container.on('change', '.related-widget-wrapper select', updateLinks);
+    container.find('.related-widget-wrapper select').each(updateLinks);
+    container.on('click', '.related-widget-wrapper-link', function(event){
+        if (this.href) {
+            showRelatedObjectPopup(this);
+        }
+        event.preventDefault();
+    });
+});

django/contrib/admin/templates/admin/delete_confirmation.html

@@ -36,6 +36,8 @@
     <form action="" method="post">{% csrf_token %}
     <div>
     <input type="hidden" name="post" value="yes" />
+    {% if is_popup %}<input type="hidden" name="{{ is_popup_var }}" value="1" />{% endif %}
+    {% if to_field %}<input type="hidden" name="{{ to_field_var }}" value="{{ to_field }}" />{% endif %}
     <input type="submit" value="{% trans "Yes, I'm sure" %}" />
     <a href="#" onclick="window.history.back(); return false;" class="button cancel-link">{% trans "No, take me back" %}</a>
     </div>

django/contrib/admin/templates/admin/popup_response.html

@@ -3,7 +3,13 @@
   <head><title></title></head>
   <body>
     <script type="text/javascript">
-      opener.dismissAddAnotherPopup(window, "{{ value }}", "{{ obj }}");
+      {% if action == 'change' %}
+        opener.dismissChangeRelatedObjectPopup(window, "{{ value }}", "{{ obj }}", "{{ new_value }}");
+      {% elif action == 'delete' %}
+        opener.dismissDeleteRelatedObjectPopup(window, "{{ value }}");
+      {% else %}
+        opener.dismissAddRelatedObjectPopup(window, "{{ value }}", "{{ obj }}");
+      {% endif %}
     </script>
   </body>
 </html>

django/contrib/admin/templates/admin/related_widget_wrapper.html

+{% load i18n admin_static %}
+<div class="related-widget-wrapper">
+    {{ widget }}
+    {% block links %}
+        {% if can_change_related %}
+        <a class="related-widget-wrapper-link change-related" id="change_id_{{ name }}"
+            data-href-template="{{ change_related_template_url }}?{{ url_params }}"
+            title="{% blocktrans %}Change selected {{ model }}{% endblocktrans %}">
+            <img src="{% static 'admin/img/icon_changelink.gif' %}" width="10" height="10"
+                alt="{% trans 'Change' %}"/>
+        </a>
+        {% endif %}
+        {% if can_add_related %}
+        <a class="related-widget-wrapper-link add-related" id="add_id_{{ name }}"
+            href="{{ add_related_url }}?{{ url_params }}"
+            title="{% blocktrans %}Add another {{ model }}{% endblocktrans %}">
+            <img src="{% static 'admin/img/icon_addlink.gif' %}" width="10" height="10"
+                alt="{% trans 'Add' %}"/>
+        </a>
+        {% endif %}
+        {% if can_delete_related %}
+        <a class="related-widget-wrapper-link delete-related" id="delete_id_{{ name }}"
+            data-href-template="{{ delete_related_template_url }}?{{ url_params }}"
+            title="{% blocktrans %}Delete selected {{ model }}{% endblocktrans %}">
+            <img src="{% static 'admin/img/icon_deletelink.gif' %}" width="10" height="10"
+                alt="{% trans 'Delete' %}"/>
+        </a>
+        {% endif %}
+    {% endblock %}
+</div>

django/contrib/admin/widgets.py

@@ -8,8 +8,10 @@ import copy
 from django import forms
 from django.contrib.admin.templatetags.admin_static import static
 from django.core.urlresolvers import reverse
-from django.forms.widgets import RadioFieldRenderer
+from django.db.models.deletion import CASCADE
+from django.forms.widgets import Media, RadioFieldRenderer
 from django.forms.utils import flatatt
+from django.template.loader import render_to_string
 from django.utils.html import escape, format_html, format_html_join, smart_urlquote
 from django.utils.text import Truncator
 from django.utils.translation import ugettext as _
@@ -232,7 +234,10 @@ class RelatedFieldWidgetWrapper(forms.Widget):
     This class is a wrapper to a given widget to add the add icon for the
     admin interface.
     """
-    def __init__(self, widget, rel, admin_site, can_add_related=None):
+    template = 'admin/related_widget_wrapper.html'
+
+    def __init__(self, widget, rel, admin_site, can_add_related=None,
+                 can_change_related=False, can_delete_related=False):
         self.needs_multipart_form = widget.needs_multipart_form
         self.attrs = widget.attrs
         self.choices = widget.choices
@@ -243,6 +248,12 @@ class RelatedFieldWidgetWrapper(forms.Widget):
         if can_add_related is None:
             can_add_related = rel.to in admin_site._registry
         self.can_add_related = can_add_related
+        # XXX: The UX does not support multiple selected values.
+        multiple = getattr(widget, 'allow_multiple_selected', False)
+        self.can_change_related = not multiple and can_change_related
+        # XXX: The deletion UX can be confusing when dealing with cascading deletion.
+        cascade = getattr(rel, 'on_delete', None) is CASCADE
+        self.can_delete_related = not multiple and not cascade and can_delete_related
         # so we can check if the related object is registered with this AdminSite
         self.admin_site = admin_site
 
@@ -259,22 +270,47 @@ class RelatedFieldWidgetWrapper(forms.Widget):
 
     @property
     def media(self):
-        return self.widget.media
+        media = Media(js=['admin/js/related-widget-wrapper.js'])
+        return self.widget.media + media
+
+    def get_related_url(self, info, action, *args):
+        return reverse("admin:%s_%s_%s" % (info + (action,)),
+                       current_app=self.admin_site.name, args=args)
 
     def render(self, name, value, *args, **kwargs):
-        from django.contrib.admin.views.main import TO_FIELD_VAR
+        from django.contrib.admin.views.main import IS_POPUP_VAR, TO_FIELD_VAR
+        rel_opts = self.rel.to._meta
+        info = (rel_opts.app_label, rel_opts.model_name)
         self.widget.choices = self.choices
-        output = [self.widget.render(name, value, *args, **kwargs)]
+        url_params = '&'.join("%s=%s" % param for param in [
+            (TO_FIELD_VAR, self.rel.get_related_field().name),
+            (IS_POPUP_VAR, 1),
+        ])
+        context = {
+            'widget': self.widget.render(name, value, *args, **kwargs),
+            'name': name,
+            'url_params': url_params,
+            'model': rel_opts.verbose_name,
+        }
+        if self.can_change_related:
+            change_related_template_url = self.get_related_url(info, 'change', '__fk__')
+            context.update(
+                can_change_related=True,
+                change_related_template_url=change_related_template_url,
+            )
         if self.can_add_related:
-            rel_to = self.rel.to
-            info = (rel_to._meta.app_label, rel_to._meta.model_name)
-            related_url = reverse('admin:%s_%s_add' % info, current_app=self.admin_site.name)
-            url_params = '?%s=%s' % (TO_FIELD_VAR, self.rel.get_related_field().name)
-            # TODO: "add_id_" is hard-coded here. This should instead use the
-            # correct API to determine the ID dynamically.
-            output.append('<a href="%s%s" class="add-another" id="add_id_%s" title="%s"></a>'
-                          % (related_url, url_params, name, _('Add Another')))
-        return mark_safe(''.join(output))
+            add_related_url = self.get_related_url(info, 'add')
+            context.update(
+                can_add_related=True,
+                add_related_url=add_related_url,
+            )
+        if self.can_delete_related:
+            delete_related_template_url = self.get_related_url(info, 'delete', '__fk__')
+            context.update(
+                can_delete_related=True,
+                delete_related_template_url=delete_related_template_url,
+            )
+        return mark_safe(render_to_string(self.template, context))
 
     def build_attrs(self, extra_attrs=None, **kwargs):
         "Helper function for building an attribute dictionary."

docs/ref/contrib/admin/index.txt

@@ -1736,7 +1736,7 @@ templates used by the :class:`ModelAdmin` views:
     been saved. You can override it to change the default
     behavior after the object has been changed.
 
-.. method:: ModelAdmin.response_delete(request, obj_display)
+.. method:: ModelAdmin.response_delete(request, obj_display, obj_id)
 
     .. versionadded:: 1.7
 
@@ -1750,6 +1750,13 @@ templates used by the :class:`ModelAdmin` views:
     ``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)
 
     .. versionadded:: 1.7

docs/releases/1.8.txt

@@ -161,6 +161,9 @@ Minor features
   its value from :meth:`~django.contrib.admin.AdminSite.has_permission`,
   indicates whether the user may access the site.
 
+* Foreign key dropdowns now have buttons for changing or deleting related
+  objects using a popup.
+
 :mod:`django.contrib.admindocs`
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -913,6 +916,23 @@ those writing third-party backends in updating their code:
   ``data_type_check_constraints`` attributes have moved from the
   ``DatabaseCreation`` class to ``DatabaseWrapper``.
 
+:mod:`django.contrib.admin`
+~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+* ``AdminSite`` no longer takes an ``app_name`` argument and its ``app_name``
+  attribute has been removed. The application name is always ``admin`` (as
+  opposed to the instance name which you can still customize using
+  ``AdminSite(name="...")``.
+
+* The ``ModelAdmin.get_object()`` method (private API) now takes a third
+  argument named ``from_field`` in order to specify which field should match
+  the provided ``object_id``.
+
+* The :meth:`ModelAdmin.response_delete()
+  <django.contrib.admin.ModelAdmin.response_delete>` method
+  now takes a second argument named ``obj_id`` which is the serialized
+  identifier used to retrieve the object before deletion.
+
 Miscellaneous
 ~~~~~~~~~~~~~
 
@@ -945,11 +965,6 @@ Miscellaneous
   ``'username'``, using the the ``'unique'`` key in its
   :attr:`~django.forms.Field.error_messages` argument.
 
-* ``AdminSite`` no longer takes an ``app_name`` argument and its ``app_name``
-  attribute has been removed. The application name is always ``admin`` (as
-  opposed to the instance name which you can still customize using
-  ``AdminSite(name="...")``.
-
 * The block ``usertools`` in the ``base.html`` template of
   :mod:`django.contrib.admin` now requires the ``has_permission`` context
   variable to be set. If you have any custom admin views that use this

tests/admin_custom_urls/tests.py

@@ -50,7 +50,7 @@ class AdminCustomUrlsTest(TestCase):
         }
         response = self.client.post('/admin/admin_custom_urls/action/!add/', post_data)
         self.assertEqual(response.status_code, 200)
-        self.assertContains(response, 'dismissAddAnotherPopup')
+        self.assertContains(response, 'dismissAddRelatedObjectPopup')
         self.assertContains(response, 'Action added through a popup')
 
     def test_admin_URLs_no_clash(self):

tests/admin_views/admin.py

@@ -53,6 +53,7 @@ callable_year.admin_order_field = 'date'
 
 class ArticleInline(admin.TabularInline):
     model = Article
+    fk_name = 'section'
     prepopulated_fields = {
         'title': ('content',)
     }
@@ -93,7 +94,7 @@ class ArticleAdmin(admin.ModelAdmin):
         }),
         ('Some other fields', {
             'classes': ('wide',),
-            'fields': ('date', 'section')
+            'fields': ('date', 'section', 'sub_section')
         })
     )
 

tests/admin_views/models.py

@@ -32,6 +32,7 @@ class Article(models.Model):
     content = models.TextField()
     date = models.DateTimeField()
     section = models.ForeignKey(Section, null=True, blank=True)
+    sub_section = models.ForeignKey(Section, null=True, blank=True, on_delete=models.SET_NULL, related_name='+')
 
     def __str__(self):
         return self.title
@@ -545,7 +546,7 @@ class Pizza(models.Model):
 
 
 class Album(models.Model):
-    owner = models.ForeignKey(User)
+    owner = models.ForeignKey(User, null=True, blank=True, on_delete=models.SET_NULL)
     title = models.CharField(max_length=30)
 
 

tests/admin_views/tests.py

@@ -180,7 +180,7 @@ class AdminViewBasicTest(AdminViewBasicTestCase):
         }
         response = self.client.post('/test_admin/%s/admin_views/article/add/' % self.urlbit, post_data)
         self.assertEqual(response.status_code, 200)
-        self.assertContains(response, 'dismissAddAnotherPopup')
+        self.assertContains(response, 'dismissAddRelatedObjectPopup')
         self.assertContains(response, 'title with a new\\u000Aline')
 
     # Post data for edit inline
@@ -648,8 +648,8 @@ class AdminViewBasicTest(AdminViewBasicTestCase):
         response = self.client.get("/test_admin/admin/admin_views/referencedbyinline/", {TO_FIELD_VAR: 'name'})
         self.assertEqual(response.status_code, 200)
 
-        # We also want to prevent the add and change view from leaking a
-        # disallowed field value.
+        # We also want to prevent the add, change, and delete views from
+        # leaking a disallowed field value.
         with patch_logger('django.security.DisallowedModelAdminToField', 'error') as calls:
             response = self.client.post("/test_admin/admin/admin_views/section/add/", {TO_FIELD_VAR: 'name'})
             self.assertEqual(response.status_code, 400)
@@ -661,6 +661,11 @@ class AdminViewBasicTest(AdminViewBasicTestCase):
             self.assertEqual(response.status_code, 400)
             self.assertEqual(len(calls), 1)
 
+        with patch_logger('django.security.DisallowedModelAdminToField', 'error') as calls:
+            response = self.client.post("/test_admin/admin/admin_views/section/%d/delete/" % section.pk, {TO_FIELD_VAR: 'name'})
+            self.assertEqual(response.status_code, 400)
+            self.assertEqual(len(calls), 1)
+
     def test_allowed_filtering_15103(self):
         """
         Regressions test for ticket 15103 - filtering on fields defined in a
@@ -1472,21 +1477,75 @@ class AdminViewPermissionsTest(TestCase):
         login_url = reverse('admin:login') + '?next=/test_admin/admin/'
         # Set up and log in user.
         url = '/test_admin/admin/admin_views/article/add/'
-        add_link_text = ' class="add-another"'
-        self.client.get('/test_admin/admin/')
+        add_link_text = 'add_id_section'
         self.client.post(login_url, self.adduser_login)
-        # The add user can't add sections yet, so they shouldn't see the "add
+        # The user can't add sections yet, so they shouldn't see the "add
         # section" link.
         response = self.client.get(url)
         self.assertNotContains(response, add_link_text)
-        # Allow the add user to add sections too. Now they can see the "add
+        # Allow the user to add sections too. Now they can see the "add
         # section" link.
-        add_user = User.objects.get(username='adduser')
+        user = User.objects.get(username='adduser')
         perm = get_perm(Section, get_permission_codename('add', Section._meta))
-        add_user.user_permissions.add(perm)
+        user.user_permissions.add(perm)
         response = self.client.get(url)
         self.assertContains(response, add_link_text)
 
+    def test_conditionally_show_change_section_link(self):
+        """
+        The foreign key widget should only show the "change related" button if
+        the user has permission to change that related item.
+        """
+        def get_change_related(response):
+            return response.context['adminform'].form.fields['section'].widget.can_change_related
+
+        login_url = reverse('admin:login')
+        # Set up and log in user.
+        url = '/test_admin/admin/admin_views/article/add/'
+        change_link_text = 'change_id_section'
+        self.client.post(login_url, self.adduser_login)
+        # The user can't change sections yet, so they shouldn't see the "change
+        # section" link.
+        response = self.client.get(url)
+        self.assertFalse(get_change_related(response))
+        self.assertNotContains(response, change_link_text)
+        # Allow the user to change sections too. Now they can see the "change
+        # section" link.
+        user = User.objects.get(username='adduser')
+        perm = get_perm(Section, get_permission_codename('change', Section._meta))
+        user.user_permissions.add(perm)
+        response = self.client.get(url)
+        self.assertTrue(get_change_related(response))
+        self.assertContains(response, change_link_text)
+
+    def test_conditionally_show_delete_section_link(self):
+        """
+        The foreign key widget should only show the "delete related" button if
+        the user has permission to delete that related item.
+        """
+        def get_delete_related(response):
+            return response.context['adminform'].form.fields['sub_section'].widget.can_delete_related
+
+        login_url = reverse('admin:login')
+        # Set up and log in user.
+        url = '/test_admin/admin/admin_views/article/add/'
+        delete_link_text = 'delete_id_sub_section'
+        self.client.get('/test_admin/admin/')
+        self.client.post(login_url, self.adduser_login)
+        # The user can't delete sections yet, so they shouldn't see the "delete
+        # section" link.
+        response = self.client.get(url)
+        self.assertFalse(get_delete_related(response))
+        self.assertNotContains(response, delete_link_text)
+        # Allow the user to delete sections too. Now they can see the "delete
+        # section" link.
+        user = User.objects.get(username='adduser')
+        perm = get_perm(Section, get_permission_codename('delete', Section._meta))
+        user.user_permissions.add(perm)
+        response = self.client.get(url)
+        self.assertTrue(get_delete_related(response))
+        self.assertContains(response, delete_link_text)
+
     def test_custom_model_admin_templates(self):
         login_url = reverse('admin:login') + '?next=/test_admin/admin/'
         self.client.get('/test_admin/admin/')
@@ -4140,12 +4199,12 @@ class UserAdminTest(TestCase):
         self.assertEqual(adminform.form.errors['password2'],
             ["The two password fields didn't match."])
 
-    def test_user_fk_popup(self):
-        """Quick user addition in a FK popup shouldn't invoke view for further user customization"""
+    def test_user_fk_add_popup(self):
+        """User addition through a FK popup should return the appropriate JavaScript response."""
         response = self.client.get('/test_admin/admin/admin_views/album/add/')
         self.assertEqual(response.status_code, 200)
         self.assertContains(response, '/test_admin/admin/auth/user/add')
-        self.assertContains(response, 'class="add-another" id="add_id_owner"')
+        self.assertContains(response, 'class="related-widget-wrapper-link add-related" id="add_id_owner"')
         response = self.client.get('/test_admin/admin/auth/user/add/?_popup=1')
         self.assertEqual(response.status_code, 200)
         self.assertNotContains(response, 'name="_continue"')
@@ -4159,7 +4218,52 @@ class UserAdminTest(TestCase):
         }
         response = self.client.post('/test_admin/admin/auth/user/add/?_popup=1', data, follow=True)
         self.assertEqual(response.status_code, 200)
-        self.assertContains(response, 'dismissAddAnotherPopup')
+        self.assertContains(response, 'dismissAddRelatedObjectPopup')
+
+    def test_user_fk_change_popup(self):
+        """User change through a FK popup should return the appropriate JavaScript response."""
+        response = self.client.get('/test_admin/admin/admin_views/album/add/')
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, '/test_admin/admin/auth/user/__fk__/')
+        self.assertContains(response, 'class="related-widget-wrapper-link change-related" id="change_id_owner"')
+        user = User.objects.get(username='changeuser')
+        url = "/test_admin/admin/auth/user/%s/?_popup=1" % user.pk
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 200)
+        self.assertNotContains(response, 'name="_continue"')
+        self.assertNotContains(response, 'name="_addanother"')
+        data = {
+            'username': 'newuser',
+            'password1': 'newpassword',
+            'password2': 'newpassword',
+            'last_login_0': '2007-05-30',
+            'last_login_1': '13:20:10',
+            'date_joined_0': '2007-05-30',
+            'date_joined_1': '13:20:10',
+            '_popup': '1',
+            '_save': '1',
+        }
+        response = self.client.post(url, data, follow=True)
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, 'dismissChangeRelatedObjectPopup')
+
+    def test_user_fk_delete_popup(self):
+        """User deletion through a FK popup should return the appropriate JavaScript response."""
+        response = self.client.get('/test_admin/admin/admin_views/album/add/')
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, '/test_admin/admin/auth/user/__fk__/delete/')
+        self.assertContains(response, 'class="related-widget-wrapper-link change-related" id="change_id_owner"')
+        user = User.objects.get(username='changeuser')
+        url = "/test_admin/admin/auth/user/%s/delete/?_popup=1" % user.pk
+        response = self.client.get(url)
+        self.assertEqual(response.status_code, 200)
+        data = {
+            'post': 'yes',
+            '_popup': '1',
+        }
+        response = self.client.post(url, data, follow=True)
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, 'dismissDeleteRelatedObjectPopup')
 
     def test_save_add_another_button(self):
         user_count = User.objects.count()

tests/admin_widgets/models.py

@@ -108,7 +108,8 @@ class Individual(models.Model):
     related instances (rendering will be called programmatically in this case).
     """
     name = models.CharField(max_length=20)
-    parent = models.ForeignKey('self', null=True)
+    parent = models.ForeignKey('self', null=True, on_delete=models.SET_NULL)
+    soulmate = models.ForeignKey('self', null=True, on_delete=models.CASCADE, related_name='soulmates')
 
 
 class Company(models.Model):

tests/admin_widgets/tests.py

@@ -510,6 +510,32 @@ class RelatedFieldWidgetWrapperTests(DjangoTestCase):
         w = widgets.RelatedFieldWidgetWrapper(w, rel, widget_admin_site)
         self.assertFalse(w.can_add_related)
 
+    def test_select_multiple_widget_cant_change_delete_related(self):
+        rel = models.Individual._meta.get_field('parent').rel
+        widget = forms.SelectMultiple()
+        wrapper = widgets.RelatedFieldWidgetWrapper(
+            widget, rel, widget_admin_site,
+            can_add_related=True,
+            can_change_related=True,
+            can_delete_related=True,
+        )
+        self.assertTrue(wrapper.can_add_related)
+        self.assertFalse(wrapper.can_change_related)
+        self.assertFalse(wrapper.can_delete_related)
+
+    def test_on_delete_cascade_rel_cant_delete_related(self):
+        rel = models.Individual._meta.get_field('soulmate').rel
+        widget = forms.Select()
+        wrapper = widgets.RelatedFieldWidgetWrapper(
+            widget, rel, widget_admin_site,
+            can_add_related=True,
+            can_change_related=True,
+            can_delete_related=True,
+        )
+        self.assertTrue(wrapper.can_add_related)
+        self.assertTrue(wrapper.can_change_related)
+        self.assertFalse(wrapper.can_delete_related)
+
 
 @override_settings(PASSWORD_HASHERS=('django.contrib.auth.hashers.SHA1PasswordHasher',),
     ROOT_URLCONF='admin_widgets.urls')
@@ -1134,9 +1160,27 @@ class RelatedFieldWidgetSeleniumFirefoxTests(AdminSeleniumWebDriverTestCase):
         # The field now contains the new user
         self.wait_for('#id_user option[value="newuser"]')
 
+        # Click the Change User button to change it
+        self.selenium.find_element_by_id('change_id_user').click()
+        self.selenium.switch_to_window('id_user')
+        self.wait_page_loaded()
+
+        username_field = self.selenium.find_element_by_id('id_username')
+        username_value = 'changednewuser'
+        username_field.clear()
+        username_field.send_keys(username_value)
+
+        save_button_css_selector = '.submit-row > input[type=submit]'
+        self.selenium.find_element_by_css_selector(save_button_css_selector).click()
+        self.selenium.switch_to_window(main_window)
+        # Wait up to 2 seconds for the new option to show up after clicking save in the popup.
+        self.selenium.implicitly_wait(2)
+        self.selenium.find_element_by_css_selector('#id_user option[value=changednewuser]')
+        self.selenium.implicitly_wait(0)
+
         # Go ahead and submit the form to make sure it works
         self.selenium.find_element_by_css_selector(save_button_css_selector).click()
-        self.wait_for_text('li.success', 'The profile "newuser" was added successfully.')
+        self.wait_for_text('li.success', 'The profile "changednewuser" was added successfully.')
         profiles = models.Profile.objects.all()
         self.assertEqual(len(profiles), 1)
         self.assertEqual(profiles[0].user.username, username_value)

tests/modeladmin/tests.py

@@ -355,30 +355,30 @@ class ModelAdminTests(TestCase):
         form = ma.get_form(request)()
 
         self.assertHTMLEqual(str(form["main_band"]),
-            '<select name="main_band" id="id_main_band">\n'
-            '<option value="" selected="selected">---------</option>\n'
-            '<option value="%d">The Beatles</option>\n'
-            '<option value="%d">The Doors</option>\n'
-            '</select>' % (band2.id, self.band.id))
+            '<div class="related-widget-wrapper">'
+            '<select name="main_band" id="id_main_band">'
+            '<option value="" selected="selected">---------</option>'
+            '<option value="%d">The Beatles</option>'
+            '<option value="%d">The Doors</option>'
+            '</select></div>' % (band2.id, self.band.id))
 
         class AdminConcertForm(forms.ModelForm):
-            pass
-
             def __init__(self, *args, **kwargs):
                 super(AdminConcertForm, self).__init__(*args, **kwargs)
                 self.fields["main_band"].queryset = Band.objects.filter(name='The Doors')
 
-        class ConcertAdmin(ModelAdmin):
+        class ConcertAdminWithForm(ModelAdmin):
             form = AdminConcertForm
 
-        ma = ConcertAdmin(Concert, self.site)
+        ma = ConcertAdminWithForm(Concert, self.site)
         form = ma.get_form(request)()
 
         self.assertHTMLEqual(str(form["main_band"]),
-            '<select name="main_band" id="id_main_band">\n'
-            '<option value="" selected="selected">---------</option>\n'
-            '<option value="%d">The Doors</option>\n'
-            '</select>' % self.band.id)
+            '<div class="related-widget-wrapper">'
+            '<select name="main_band" id="id_main_band">'
+            '<option value="" selected="selected">---------</option>'
+            '<option value="%d">The Doors</option>'
+            '</select></div>' % self.band.id)
 
     def test_regression_for_ticket_15820(self):
         """