Support URLPattern and URLResolver from Django 2.0 (#5500)

* Support URLPattern and URLResolver from Django 2.0

* fix import order

rest_framework/compat.py

@@ -25,14 +25,35 @@
 
 try:
     from django.urls import (
-        NoReverseMatch, RegexURLPattern, RegexURLResolver, ResolverMatch, Resolver404, get_script_prefix, reverse, reverse_lazy, resolve
+        NoReverseMatch, URLPattern as RegexURLPattern, URLResolver as RegexURLResolver, ResolverMatch, Resolver404, get_script_prefix, reverse, reverse_lazy, resolve
     )
+
 except ImportError:
     from django.core.urlresolvers import (  # Will be removed in Django 2.0
         NoReverseMatch, RegexURLPattern, RegexURLResolver, ResolverMatch, Resolver404, get_script_prefix, reverse, reverse_lazy, resolve
     )
 
 
+def get_regex_pattern(urlpattern):
+    if hasattr(urlpattern, 'pattern'):
+        # Django 2.0
+        return urlpattern.pattern.regex.pattern
+    else:
+        # Django < 2.0
+        return urlpattern.regex.pattern
+
+
+def make_url_resolver(regex, urlpatterns):
+    try:
+        # Django 2.0
+        from django.urls.resolvers import RegexPattern
+        return RegexURLResolver(RegexPattern(regex), urlpatterns)
+
+    except ImportError:
+        # Django < 2.0
+        return RegexURLResolver(regex, urlpatterns)
+
+
 try:
     import urlparse  # Python 2.x
 except ImportError:

rest_framework/schemas/generators.py

@@ -15,7 +15,7 @@
 
 from rest_framework import exceptions
 from rest_framework.compat import (
-    RegexURLPattern, RegexURLResolver, coreapi, coreschema
+    RegexURLPattern, RegexURLResolver, coreapi, coreschema, get_regex_pattern
 )
 from rest_framework.request import clone_request
 from rest_framework.settings import api_settings
@@ -135,7 +135,7 @@ def get_api_endpoints(self, patterns=None, prefix=''):
         api_endpoints = []
 
         for pattern in patterns:
-            path_regex = prefix + pattern.regex.pattern
+            path_regex = prefix + get_regex_pattern(pattern)
             if isinstance(pattern, RegexURLPattern):
                 path = self.get_path_from_regex(path_regex)
                 callback = pattern.callback

rest_framework/urlpatterns.py

@@ -2,7 +2,7 @@
 
 from django.conf.urls import include, url
 
-from rest_framework.compat import RegexURLResolver
+from rest_framework.compat import RegexURLResolver, get_regex_pattern
 from rest_framework.settings import api_settings
 
 
@@ -11,7 +11,7 @@ def apply_suffix_patterns(urlpatterns, suffix_pattern, suffix_required):
     for urlpattern in urlpatterns:
         if isinstance(urlpattern, RegexURLResolver):
             # Set of included URL patterns
-            regex = urlpattern.regex.pattern
+            regex = get_regex_pattern(urlpattern)
             namespace = urlpattern.namespace
             app_name = urlpattern.app_name
             kwargs = urlpattern.default_kwargs
@@ -22,7 +22,7 @@ def apply_suffix_patterns(urlpatterns, suffix_pattern, suffix_required):
             ret.append(url(regex, include((patterns, app_name), namespace), kwargs))
         else:
             # Regular URL pattern
-            regex = urlpattern.regex.pattern.rstrip('$').rstrip('/') + suffix_pattern
+            regex = get_regex_pattern(urlpattern).rstrip('$').rstrip('/') + suffix_pattern
             view = urlpattern.callback
             kwargs = urlpattern.default_args
             name = urlpattern.name

tests/test_urlpatterns.py

@@ -5,7 +5,7 @@
 from django.conf.urls import include, url
 from django.test import TestCase
 
-from rest_framework.compat import RegexURLResolver, Resolver404
+from rest_framework.compat import Resolver404, make_url_resolver
 from rest_framework.test import APIRequestFactory
 from rest_framework.urlpatterns import format_suffix_patterns
 
@@ -28,7 +28,7 @@ def _resolve_urlpatterns(self, urlpatterns, test_paths):
             urlpatterns = format_suffix_patterns(urlpatterns)
         except Exception:
             self.fail("Failed to apply `format_suffix_patterns` on  the supplied urlpatterns")
-        resolver = RegexURLResolver(r'^/', urlpatterns)
+        resolver = make_url_resolver(r'^/', urlpatterns)
         for test_path in test_paths:
             request = factory.get(test_path.path)
             try:
@@ -43,7 +43,7 @@ def test_trailing_slash(self):
         urlpatterns = format_suffix_patterns([
             url(r'^test/$', dummy_view),
         ])
-        resolver = RegexURLResolver(r'^/', urlpatterns)
+        resolver = make_url_resolver(r'^/', urlpatterns)
 
         test_paths = [
             (URLTestPath('/test.api', (), {'format': 'api'}), True),