Ensures that default template tags are loaded for Django 1.11

setup.py

@@ -35,7 +35,7 @@ def package_data(pkg, root_list):
 
 setup(
     name='xblock-utils',
-    version='1.1.0',
+    version='1.1.1',
     description='Various utilities for XBlocks',
     packages=[
         'xblockutils',

tests/unit/data/l10n_django_template.txt

+{% load l10n %}
+{{ 1000|localize }}
+{{ 1000|unlocalize }}

tests/unit/test_resources.py

@@ -90,6 +90,12 @@ mUlTi_LiNe TrAnSlAtIoN: This is a fine name
 
 """
 
+expected_localized_template = u"""\
+
+1000
+1000
+"""
+
 example_id = "example-unique-id"
 
 expected_filled_js_template = u"""\
@@ -167,6 +173,14 @@ class TestResourceLoader(unittest.TestCase):
         s = loader.render_django_template("data/trans_django_template.txt", example_context)
         self.assertEquals(s, expected_not_translated_template)
 
+    def test_render_django_template_localized(self):
+        # Test that default template tags like l10n are loaded
+        loader = ResourceLoader(__name__)
+        s = loader.render_django_template("data/l10n_django_template.txt",
+                                          context=example_context,
+                                          i18n_service=MockI18nService())
+        self.assertEquals(s, expected_localized_template)
+
     def test_render_mako_template(self):
         loader = ResourceLoader(__name__)
         s = loader.render_mako_template("data/simple_mako_template.txt", example_context)

xblockutils/resources.py

@@ -68,7 +68,11 @@ class ResourceLoader(object):
             engine = Engine()
         else:
             # Django>1.8 Engine can load the extra templatetag libraries itself
-            engine = Engine(libraries=libraries)
+            # but we have to override the default installed libraries.
+            from django.template.backends.django import get_installed_libraries
+            installed_libraries = get_installed_libraries()
+            installed_libraries.update(libraries)
+            engine = Engine(libraries=installed_libraries)
 
         template_str = self.load_unicode(template_path)
         template = Template(template_str, engine=engine)