diff --git a/django/forms/widgets.py b/django/forms/widgets.py
index 02aa32b207..e944091f0d 100644
--- a/django/forms/widgets.py
+++ b/django/forms/widgets.py
@@ -6,16 +6,21 @@ import copy
import datetime
import re
import warnings
+from collections import defaultdict
from itertools import chain
from django.conf import settings
from django.forms.utils import to_current_timezone
from django.templatetags.static import static
from django.utils import datetime_safe, formats
+from django.utils.datastructures import OrderedSet
from django.utils.dates import MONTHS
from django.utils.formats import get_format
from django.utils.html import format_html, html_safe
from django.utils.safestring import mark_safe
+from django.utils.topological_sort import (
+ CyclicDependencyError, stable_topological_sort,
+)
from django.utils.translation import gettext_lazy as _
from .renderers import get_default_renderer
@@ -59,22 +64,15 @@ class Media:
@property
def _css(self):
- css = self._css_lists[0]
- # filter(None, ...) avoids calling merge with empty dicts.
- for obj in filter(None, self._css_lists[1:]):
- css = {
- medium: self.merge(css.get(medium, []), obj.get(medium, []))
- for medium in css.keys() | obj.keys()
- }
- return css
+ css = defaultdict(list)
+ for css_list in self._css_lists:
+ for medium, sublist in css_list.items():
+ css[medium].append(sublist)
+ return {medium: self.merge(*lists) for medium, lists in css.items()}
@property
def _js(self):
- js = self._js_lists[0]
- # filter(None, ...) avoids calling merge() with empty lists.
- for obj in filter(None, self._js_lists[1:]):
- js = self.merge(js, obj)
- return js
+ return self.merge(*self._js_lists)
def render(self):
return mark_safe('\n'.join(chain.from_iterable(getattr(self, 'render_' + name)() for name in MEDIA_TYPES)))
@@ -115,39 +113,37 @@ class Media:
raise KeyError('Unknown media type "%s"' % name)
@staticmethod
- def merge(list_1, list_2):
+ def merge(*lists):
"""
- Merge two lists while trying to keep the relative order of the elements.
- Warn if the lists have the same two elements in a different relative
- order.
+ Merge lists while trying to keep the relative order of the elements.
+ Warn if the lists have the same elements in a different relative order.
For static assets it can be important to have them included in the DOM
in a certain order. In JavaScript you may not be able to reference a
global or in CSS you might want to override a style.
"""
- # Start with a copy of list_1.
- combined_list = list(list_1)
- last_insert_index = len(list_1)
- # Walk list_2 in reverse, inserting each element into combined_list if
- # it doesn't already exist.
- for path in reversed(list_2):
- try:
- # Does path already exist in the list?
- index = combined_list.index(path)
- except ValueError:
- # Add path to combined_list since it doesn't exist.
- combined_list.insert(last_insert_index, path)
- else:
- if index > last_insert_index:
- warnings.warn(
- 'Detected duplicate Media files in an opposite order:\n'
- '%s\n%s' % (combined_list[last_insert_index], combined_list[index]),
- MediaOrderConflictWarning,
- )
- # path already exists in the list. Update last_insert_index so
- # that the following elements are inserted in front of this one.
- last_insert_index = index
- return combined_list
+ dependency_graph = defaultdict(set)
+ all_items = OrderedSet()
+ for list_ in filter(None, lists):
+ head = list_[0]
+ # The first items depend on nothing but have to be part of the
+ # dependency graph to be included in the result.
+ dependency_graph.setdefault(head, set())
+ for item in list_:
+ all_items.add(item)
+ # No self dependencies
+ if head != item:
+ dependency_graph[item].add(head)
+ head = item
+ try:
+ return stable_topological_sort(all_items, dependency_graph)
+ except CyclicDependencyError:
+ warnings.warn(
+ 'Detected duplicate Media files in an opposite order: {}'.format(
+ ', '.join(repr(l) for l in lists)
+ ), MediaOrderConflictWarning,
+ )
+ return list(all_items)
def __add__(self, other):
combined = Media()
diff --git a/tests/admin_inlines/tests.py b/tests/admin_inlines/tests.py
index 0a1ab5acbb..5272d44f35 100644
--- a/tests/admin_inlines/tests.py
+++ b/tests/admin_inlines/tests.py
@@ -497,10 +497,10 @@ class TestInlineMedia(TestDataMixin, TestCase):
response.context['inline_admin_formsets'][0].media._js,
[
'admin/js/vendor/jquery/jquery.min.js',
- 'admin/js/jquery.init.js',
- 'admin/js/inlines.min.js',
'my_awesome_inline_scripts.js',
'custom_number.js',
+ 'admin/js/jquery.init.js',
+ 'admin/js/inlines.min.js',
]
)
self.assertContains(response, 'my_awesome_inline_scripts.js')
diff --git a/tests/admin_widgets/test_autocomplete_widget.py b/tests/admin_widgets/test_autocomplete_widget.py
index cd9d58e347..601929fd37 100644
--- a/tests/admin_widgets/test_autocomplete_widget.py
+++ b/tests/admin_widgets/test_autocomplete_widget.py
@@ -139,4 +139,4 @@ class AutocompleteMixinTests(TestCase):
else:
expected_files = base_files
with translation.override(lang):
- self.assertEqual(AutocompleteSelect(rel, admin.site).media._js, expected_files)
+ self.assertEqual(AutocompleteSelect(rel, admin.site).media._js, list(expected_files))
diff --git a/tests/forms_tests/tests/test_media.py b/tests/forms_tests/tests/test_media.py
index 8cb484a15e..192d78f331 100644
--- a/tests/forms_tests/tests/test_media.py
+++ b/tests/forms_tests/tests/test_media.py
@@ -25,8 +25,8 @@ class FormsMediaTestCase(SimpleTestCase):
)
self.assertEqual(
repr(m),
- "Media(css={'all': ('path/to/css1', '/path/to/css2')}, "
- "js=('/path/to/js1', 'http://media.other.com/path/to/js2', 'https://secure.other.com/path/to/js3'))"
+ "Media(css={'all': ['path/to/css1', '/path/to/css2']}, "
+ "js=['/path/to/js1', 'http://media.other.com/path/to/js2', 'https://secure.other.com/path/to/js3'])"
)
class Foo:
@@ -125,8 +125,8 @@ class FormsMediaTestCase(SimpleTestCase):
-
-"""
+
+"""
)
# media addition hasn't affected the original objects
@@ -151,6 +151,17 @@ class FormsMediaTestCase(SimpleTestCase):
self.assertEqual(str(w4.media), """
""")
+ def test_media_deduplication(self):
+ # A deduplication test applied directly to a Media object, to confirm
+ # that the deduplication doesn't only happen at the point of merging
+ # two or more media objects.
+ media = Media(
+ css={'all': ('/path/to/css1', '/path/to/css1')},
+ js=('/path/to/js1', '/path/to/js1'),
+ )
+ self.assertEqual(str(media), """
+""")
+
def test_media_property(self):
###############################################################
# Property-based media definitions
@@ -197,12 +208,12 @@ class FormsMediaTestCase(SimpleTestCase):
self.assertEqual(
str(w6.media),
"""
-
+
+
-
-"""
+"""
)
def test_media_inheritance(self):
@@ -247,8 +258,8 @@ class FormsMediaTestCase(SimpleTestCase):
-
-"""
+
+"""
)
def test_media_inheritance_from_property(self):
@@ -322,8 +333,8 @@ class FormsMediaTestCase(SimpleTestCase):
-
-"""
+
+"""
)
def test_media_inheritance_single_type(self):
@@ -420,8 +431,8 @@ class FormsMediaTestCase(SimpleTestCase):
-
-"""
+
+"""
)
def test_form_media(self):
@@ -462,8 +473,8 @@ class FormsMediaTestCase(SimpleTestCase):
-
-"""
+
+"""
)
# Form media can be combined to produce a single media definition.
@@ -477,8 +488,8 @@ class FormsMediaTestCase(SimpleTestCase):
-
-"""
+
+"""
)
# Forms can also define media, following the same rules as widgets.
@@ -495,28 +506,28 @@ class FormsMediaTestCase(SimpleTestCase):
self.assertEqual(
str(f3.media),
"""
+
-
+
-
-"""
+"""
)
# Media works in templates
self.assertEqual(
Template("{{ form.media.js }}{{ form.media.css }}").render(Context({'form': f3})),
"""
+
-
-"""
+"""
"""
+
-
-"""
+"""
)
def test_html_safe(self):
@@ -526,19 +537,23 @@ class FormsMediaTestCase(SimpleTestCase):
def test_merge(self):
test_values = (
- (([1, 2], [3, 4]), [1, 2, 3, 4]),
+ (([1, 2], [3, 4]), [1, 3, 2, 4]),
(([1, 2], [2, 3]), [1, 2, 3]),
(([2, 3], [1, 2]), [1, 2, 3]),
(([1, 3], [2, 3]), [1, 2, 3]),
(([1, 2], [1, 3]), [1, 2, 3]),
(([1, 2], [3, 2]), [1, 3, 2]),
+ (([1, 2], [1, 2]), [1, 2]),
+ ([[1, 2], [1, 3], [2, 3], [5, 7], [5, 6], [6, 7, 9], [8, 9]], [1, 5, 8, 2, 6, 3, 7, 9]),
+ ((), []),
+ (([1, 2],), [1, 2]),
)
- for (list1, list2), expected in test_values:
- with self.subTest(list1=list1, list2=list2):
- self.assertEqual(Media.merge(list1, list2), expected)
+ for lists, expected in test_values:
+ with self.subTest(lists=lists):
+ self.assertEqual(Media.merge(*lists), expected)
def test_merge_warning(self):
- msg = 'Detected duplicate Media files in an opposite order:\n1\n2'
+ msg = 'Detected duplicate Media files in an opposite order: [1, 2], [2, 1]'
with self.assertWarnsMessage(RuntimeWarning, msg):
self.assertEqual(Media.merge([1, 2], [2, 1]), [1, 2])
@@ -546,28 +561,30 @@ class FormsMediaTestCase(SimpleTestCase):
"""
The relative order of scripts is preserved in a three-way merge.
"""
- # custom_widget.js doesn't depend on jquery.js.
- widget1 = Media(js=['custom_widget.js'])
- widget2 = Media(js=['jquery.js', 'uses_jquery.js'])
- form_media = widget1 + widget2
- # The relative ordering of custom_widget.js and jquery.js has been
- # established (but without a real need to).
- self.assertEqual(form_media._js, ['custom_widget.js', 'jquery.js', 'uses_jquery.js'])
- # The inline also uses custom_widget.js. This time, it's at the end.
- inline_media = Media(js=['jquery.js', 'also_jquery.js']) + Media(js=['custom_widget.js'])
- merged = form_media + inline_media
- self.assertEqual(merged._js, ['custom_widget.js', 'jquery.js', 'uses_jquery.js', 'also_jquery.js'])
+ widget1 = Media(js=['color-picker.js'])
+ widget2 = Media(js=['text-editor.js'])
+ widget3 = Media(js=['text-editor.js', 'text-editor-extras.js', 'color-picker.js'])
+ merged = widget1 + widget2 + widget3
+ self.assertEqual(merged._js, ['text-editor.js', 'text-editor-extras.js', 'color-picker.js'])
+
+ def test_merge_js_three_way2(self):
+ # The merge prefers to place 'c' before 'b' and 'g' before 'h' to
+ # preserve the original order. The preference 'c'->'b' is overridden by
+ # widget3's media, but 'g'->'h' survives in the final ordering.
+ widget1 = Media(js=['a', 'c', 'f', 'g', 'k'])
+ widget2 = Media(js=['a', 'b', 'f', 'h', 'k'])
+ widget3 = Media(js=['b', 'c', 'f', 'k'])
+ merged = widget1 + widget2 + widget3
+ self.assertEqual(merged._js, ['a', 'b', 'c', 'f', 'g', 'h', 'k'])
def test_merge_css_three_way(self):
- widget1 = Media(css={'screen': ['a.css']})
- widget2 = Media(css={'screen': ['b.css']})
- widget3 = Media(css={'all': ['c.css']})
- form1 = widget1 + widget2
- form2 = widget2 + widget1
- # form1 and form2 have a.css and b.css in different order...
- self.assertEqual(form1._css, {'screen': ['a.css', 'b.css']})
- self.assertEqual(form2._css, {'screen': ['b.css', 'a.css']})
- # ...but merging succeeds as the relative ordering of a.css and b.css
- # was never specified.
- merged = widget3 + form1 + form2
- self.assertEqual(merged._css, {'screen': ['a.css', 'b.css'], 'all': ['c.css']})
+ widget1 = Media(css={'screen': ['c.css'], 'all': ['d.css', 'e.css']})
+ widget2 = Media(css={'screen': ['a.css']})
+ widget3 = Media(css={'screen': ['a.css', 'b.css', 'c.css'], 'all': ['e.css']})
+ merged = widget1 + widget2
+ # c.css comes before a.css because widget1 + widget2 establishes this
+ # order.
+ self.assertEqual(merged._css, {'screen': ['c.css', 'a.css'], 'all': ['d.css', 'e.css']})
+ merged = merged + widget3
+ # widget3 contains an explicit ordering of c.css and a.css.
+ self.assertEqual(merged._css, {'screen': ['a.css', 'b.css', 'c.css'], 'all': ['d.css', 'e.css']})