Fixed #27395 -- Added sitemap 'alternates' generation.

Updated the sitemap generator and default template to optionally
include link elements with hreflang attribute to alternate language
URLs.

2 files changed, 119 insertions, 7 deletions

diff --git a/tests/sitemaps_tests/test_http.py b/tests/sitemaps_tests/test_http.py
index 3d4e1d84dc..3281774cc5 100644
--- a/tests/sitemaps_tests/test_http.py
+++ b/tests/sitemaps_tests/test_http.py
@@ -253,8 +253,10 @@ class HTTPSitemapTests(SitemapTestsBase):
         self.assertEqual(response.status_code, 200)
 
     @override_settings(LANGUAGES=(('en', 'English'), ('pt', 'Portuguese')))
-    def test_simple_i18nsitemap_index(self):
-        "A simple i18n sitemap index can be rendered"
+    def test_simple_i18n_sitemap_index(self):
+        """
+        A simple i18n sitemap index can be rendered.
+        """
         response = self.client.get('/simple/i18n.xml')
         expected_content = """<?xml version="1.0" encoding="UTF-8"?>
 <urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xhtml="http://www.w3.org/1999/xhtml">
@@ -263,6 +265,80 @@ class HTTPSitemapTests(SitemapTestsBase):
 """.format(self.base_url, self.i18n_model.pk)
         self.assertXMLEqual(response.content.decode(), expected_content)
 
+    @override_settings(LANGUAGES=(('en', 'English'), ('pt', 'Portuguese')))
+    def test_alternate_i18n_sitemap_index(self):
+        """
+        A i18n sitemap with alternate/hreflang links can be rendered.
+        """
+        response = self.client.get('/alternates/i18n.xml')
+        url, pk = self.base_url, self.i18n_model.pk
+        expected_urls = f"""
+<url><loc>{url}/en/i18n/testmodel/{pk}/</loc><changefreq>never</changefreq><priority>0.5</priority>
+<xhtml:link rel="alternate" hreflang="en" href="{url}/en/i18n/testmodel/{pk}/"/>
+<xhtml:link rel="alternate" hreflang="pt" href="{url}/pt/i18n/testmodel/{pk}/"/>
+</url>
+<url><loc>{url}/pt/i18n/testmodel/{pk}/</loc><changefreq>never</changefreq><priority>0.5</priority>
+<xhtml:link rel="alternate" hreflang="en" href="{url}/en/i18n/testmodel/{pk}/"/>
+<xhtml:link rel="alternate" hreflang="pt" href="{url}/pt/i18n/testmodel/{pk}/"/>
+</url>
+""".replace('\n', '')
+        expected_content = f"""<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xhtml="http://www.w3.org/1999/xhtml">
+{expected_urls}
+</urlset>
+"""
+        self.assertXMLEqual(response.content.decode(), expected_content)
+
+    @override_settings(LANGUAGES=(('en', 'English'), ('pt', 'Portuguese'), ('es', 'Spanish')))
+    def test_alternate_i18n_sitemap_limited(self):
+        """
+        A i18n sitemap index with limited languages can be rendered.
+        """
+        response = self.client.get('/limited/i18n.xml')
+        url, pk = self.base_url, self.i18n_model.pk
+        expected_urls = f"""
+<url><loc>{url}/en/i18n/testmodel/{pk}/</loc><changefreq>never</changefreq><priority>0.5</priority>
+<xhtml:link rel="alternate" hreflang="en" href="{url}/en/i18n/testmodel/{pk}/"/>
+<xhtml:link rel="alternate" hreflang="es" href="{url}/es/i18n/testmodel/{pk}/"/>
+</url>
+<url><loc>{url}/es/i18n/testmodel/{pk}/</loc><changefreq>never</changefreq><priority>0.5</priority>
+<xhtml:link rel="alternate" hreflang="en" href="{url}/en/i18n/testmodel/{pk}/"/>
+<xhtml:link rel="alternate" hreflang="es" href="{url}/es/i18n/testmodel/{pk}/"/>
+</url>
+""".replace('\n', '')
+        expected_content = f"""<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xhtml="http://www.w3.org/1999/xhtml">
+{expected_urls}
+</urlset>
+"""
+        self.assertXMLEqual(response.content.decode(), expected_content)
+
+    @override_settings(LANGUAGES=(('en', 'English'), ('pt', 'Portuguese')))
+    def test_alternate_i18n_sitemap_xdefault(self):
+        """
+        A i18n sitemap index with x-default can be rendered.
+        """
+        response = self.client.get('/x-default/i18n.xml')
+        url, pk = self.base_url, self.i18n_model.pk
+        expected_urls = f"""
+<url><loc>{url}/en/i18n/testmodel/{pk}/</loc><changefreq>never</changefreq><priority>0.5</priority>
+<xhtml:link rel="alternate" hreflang="en" href="{url}/en/i18n/testmodel/{pk}/"/>
+<xhtml:link rel="alternate" hreflang="pt" href="{url}/pt/i18n/testmodel/{pk}/"/>
+<xhtml:link rel="alternate" hreflang="x-default" href="{url}/i18n/testmodel/{pk}/"/>
+</url>
+<url><loc>{url}/pt/i18n/testmodel/{pk}/</loc><changefreq>never</changefreq><priority>0.5</priority>
+<xhtml:link rel="alternate" hreflang="en" href="{url}/en/i18n/testmodel/{pk}/"/>
+<xhtml:link rel="alternate" hreflang="pt" href="{url}/pt/i18n/testmodel/{pk}/"/>
+<xhtml:link rel="alternate" hreflang="x-default" href="{url}/i18n/testmodel/{pk}/"/>
+</url>
+""".replace('\n', '')
+        expected_content = f"""<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:xhtml="http://www.w3.org/1999/xhtml">
+{expected_urls}
+</urlset>
+"""
+        self.assertXMLEqual(response.content.decode(), expected_content)
+
     def test_sitemap_without_entries(self):
         response = self.client.get('/sitemap-without-entries/sitemap.xml')
         expected_content = """<?xml version="1.0" encoding="UTF-8"?>
diff --git a/tests/sitemaps_tests/urls/http.py b/tests/sitemaps_tests/urls/http.py
index 495f60fb1a..e4cba4c42f 100644
--- a/tests/sitemaps_tests/urls/http.py
+++ b/tests/sitemaps_tests/urls/http.py
@@ -34,6 +34,18 @@ class SimpleI18nSitemap(Sitemap):
         return I18nTestModel.objects.order_by('pk').all()
 
 
+class AlternatesI18nSitemap(SimpleI18nSitemap):
+    alternates = True
+
+
+class LimitedI18nSitemap(AlternatesI18nSitemap):
+    languages = ['en', 'es']
+
+
+class XDefaultI18nSitemap(AlternatesI18nSitemap):
+    x_default = True
+
+
 class EmptySitemap(Sitemap):
     changefreq = "never"
     priority = 0.5
@@ -77,8 +89,20 @@ simple_sitemaps = {
     'simple': SimpleSitemap,
 }
 
-simple_i18nsitemaps = {
-    'simple': SimpleI18nSitemap,
+simple_i18n_sitemaps = {
+    'i18n': SimpleI18nSitemap,
+}
+
+alternates_i18n_sitemaps = {
+    'i18n-alternates': AlternatesI18nSitemap,
+}
+
+limited_i18n_sitemaps = {
+    'i18n-limited': LimitedI18nSitemap,
+}
+
+xdefault_i18n_sitemaps = {
+    'i18n-xdefault': XDefaultI18nSitemap,
 }
 
 simple_sitemaps_not_callable = {
@@ -97,7 +121,7 @@ fixed_lastmod_sitemaps = {
     'fixed-lastmod': FixedLastmodSitemap,
 }
 
-fixed_lastmod__mixed_sitemaps = {
+fixed_lastmod_mixed_sitemaps = {
     'fixed-lastmod-mixed': FixedLastmodMixedSitemap,
 }
 
@@ -151,7 +175,19 @@ urlpatterns = [
         name='django.contrib.sitemaps.views.sitemap'),
     path(
         'simple/i18n.xml', views.sitemap,
-        {'sitemaps': simple_i18nsitemaps},
+        {'sitemaps': simple_i18n_sitemaps},
+        name='django.contrib.sitemaps.views.sitemap'),
+    path(
+        'alternates/i18n.xml', views.sitemap,
+        {'sitemaps': alternates_i18n_sitemaps},
+        name='django.contrib.sitemaps.views.sitemap'),
+    path(
+        'limited/i18n.xml', views.sitemap,
+        {'sitemaps': limited_i18n_sitemaps},
+        name='django.contrib.sitemaps.views.sitemap'),
+    path(
+        'x-default/i18n.xml', views.sitemap,
+        {'sitemaps': xdefault_i18n_sitemaps},
         name='django.contrib.sitemaps.views.sitemap'),
     path(
         'simple/custom-sitemap.xml', views.sitemap,
@@ -167,7 +203,7 @@ urlpatterns = [
         name='django.contrib.sitemaps.views.sitemap'),
     path(
         'lastmod-mixed/sitemap.xml', views.sitemap,
-        {'sitemaps': fixed_lastmod__mixed_sitemaps},
+        {'sitemaps': fixed_lastmod_mixed_sitemaps},
         name='django.contrib.sitemaps.views.sitemap'),
     path(
         'lastmod/date-sitemap.xml', views.sitemap,