[2.0.x] Fixed #28871 -- Fixed initialization of autocomplete widgets in "Add another" inlines.

Also allowed autocomplete widgets to work on AdminSites with a name other
than 'admin'.

Backport of 81057645 from master

django/contrib/admin/options.py

@@ -220,7 +220,7 @@ class BaseModelAdmin(metaclass=forms.MediaDefiningClass):
         db = kwargs.get('using')
 
         if db_field.name in self.get_autocomplete_fields(request):
-            kwargs['widget'] = AutocompleteSelect(db_field.remote_field, using=db)
+            kwargs['widget'] = AutocompleteSelect(db_field.remote_field, self.admin_site, using=db)
         elif db_field.name in self.raw_id_fields:
             kwargs['widget'] = widgets.ForeignKeyRawIdWidget(db_field.remote_field, self.admin_site, using=db)
         elif db_field.name in self.radio_fields:
@@ -248,7 +248,7 @@ class BaseModelAdmin(metaclass=forms.MediaDefiningClass):
 
         autocomplete_fields = self.get_autocomplete_fields(request)
         if db_field.name in autocomplete_fields:
-            kwargs['widget'] = AutocompleteSelectMultiple(db_field.remote_field, using=db)
+            kwargs['widget'] = AutocompleteSelectMultiple(db_field.remote_field, self.admin_site, using=db)
         elif db_field.name in self.raw_id_fields:
             kwargs['widget'] = widgets.ManyToManyRawIdWidget(db_field.remote_field, self.admin_site, using=db)
         elif db_field.name in list(self.filter_vertical) + list(self.filter_horizontal):

django/contrib/admin/static/admin/js/autocomplete.js

@@ -24,15 +24,14 @@
     };
 
     $(function() {
-        $('.admin-autocomplete').djangoAdminSelect2();
+        // Initialize all autocomplete widgets except the one in the template
+        // form used when a new formset is added.
+        $('.admin-autocomplete').not('[name*=__prefix__]').djangoAdminSelect2();
     });
 
     $(document).on('formset:added', (function() {
         return function(event, $newFormset) {
-            var $widget = $newFormset.find('.admin-autocomplete');
-            // Exclude already initialized Select2 inputs.
-            $widget = $widget.not('.select2-hidden-accessible');
-            return init($widget);
+            return $newFormset.find('.admin-autocomplete').djangoAdminSelect2();
         };
     })(this));
 }(django.jQuery));

django/contrib/admin/widgets.py

@@ -400,10 +400,11 @@ class AutocompleteMixin:
     Renders the necessary data attributes for select2 and adds the static form
     media.
     """
-    url_name = 'admin:%s_%s_autocomplete'
+    url_name = '%s:%s_%s_autocomplete'
 
-    def __init__(self, rel, attrs=None, choices=(), using=None):
+    def __init__(self, rel, admin_site, attrs=None, choices=(), using=None):
         self.rel = rel
+        self.admin_site = admin_site
         self.db = using
         self.choices = choices
         if attrs is not None:
@@ -413,7 +414,7 @@ class AutocompleteMixin:
 
     def get_url(self):
         model = self.rel.model
-        return reverse(self.url_name % (model._meta.app_label, model._meta.model_name))
+        return reverse(self.url_name % (self.admin_site.name, model._meta.app_label, model._meta.model_name))
 
     def build_attrs(self, base_attrs, extra_attrs=None):
         """

tests/admin_views/test_autocomplete_view.py

@@ -17,6 +17,7 @@ PAGINATOR_SIZE = AutocompleteJsonView.paginate_by
 
 
 class AuthorAdmin(admin.ModelAdmin):
+    ordering = ['id']
     search_fields = ['id']
 
 
@@ -229,3 +230,23 @@ class SeleniumTests(AdminSeleniumTestCase):
         search.send_keys(Keys.RETURN)
         select = Select(self.selenium.find_element_by_id('id_related_questions'))
         self.assertEqual(len(select.all_selected_options), 2)
+
+    def test_inline_add_another_widgets(self):
+        def assertNoResults(row):
+            elem = row.find_element_by_css_selector('.select2-selection')
+            elem.click()  # Open the autocomplete dropdown.
+            results = self.selenium.find_element_by_css_selector('.select2-results')
+            self.assertTrue(results.is_displayed())
+            option = self.selenium.find_element_by_css_selector('.select2-results__option')
+            self.assertEqual(option.text, 'No results found')
+
+        # Autocomplete works in rows present when the page loads.
+        self.selenium.get(self.live_server_url + reverse('autocomplete_admin:admin_views_book_add'))
+        rows = self.selenium.find_elements_by_css_selector('.dynamic-authorship_set')
+        self.assertEqual(len(rows), 3)
+        assertNoResults(rows[0])
+        # Autocomplete works in rows added using the "Add another" button.
+        self.selenium.find_element_by_link_text('Add another Authorship').click()
+        rows = self.selenium.find_elements_by_css_selector('.dynamic-authorship_set')
+        self.assertEqual(len(rows), 4)
+        assertNoResults(rows[-1])

tests/admin_widgets/test_autocomplete_widget.py

 from django import forms
+from django.contrib import admin
 from django.contrib.admin.widgets import AutocompleteSelect
 from django.forms import ModelChoiceField
 from django.test import TestCase, override_settings
@@ -14,10 +15,12 @@ class AlbumForm(forms.ModelForm):
         widgets = {
             'band': AutocompleteSelect(
                 Album._meta.get_field('band').remote_field,
+                admin.site,
                 attrs={'class': 'my-class'},
             ),
             'featuring': AutocompleteSelect(
                 Album._meta.get_field('featuring').remote_field,
+                admin.site,
             )
         }
 
@@ -25,7 +28,7 @@ class AlbumForm(forms.ModelForm):
 class NotRequiredBandForm(forms.Form):
     band = ModelChoiceField(
         queryset=Album.objects.all(),
-        widget=AutocompleteSelect(Album._meta.get_field('band').remote_field),
+        widget=AutocompleteSelect(Album._meta.get_field('band').remote_field, admin.site),
         required=False,
     )
 
@@ -33,7 +36,7 @@ class NotRequiredBandForm(forms.Form):
 class RequiredBandForm(forms.Form):
     band = ModelChoiceField(
         queryset=Album.objects.all(),
-        widget=AutocompleteSelect(Album._meta.get_field('band').remote_field),
+        widget=AutocompleteSelect(Album._meta.get_field('band').remote_field, admin.site),
         required=True,
     )
 
@@ -68,7 +71,7 @@ class AutocompleteMixinTests(TestCase):
 
     def test_get_url(self):
         rel = Album._meta.get_field('band').remote_field
-        w = AutocompleteSelect(rel)
+        w = AutocompleteSelect(rel, admin.site)
         url = w.get_url()
         self.assertEqual(url, '/admin_widgets/band/autocomplete/')
 
@@ -130,4 +133,4 @@ class AutocompleteMixinTests(TestCase):
                 else:
                     expected_files = base_files
                 with translation.override(lang):
-                    self.assertEqual(AutocompleteSelect(rel).media._js, expected_files)
+                    self.assertEqual(AutocompleteSelect(rel, admin.site).media._js, expected_files)