Fixed #26013 -- Moved django.core.urlresolvers to django.urls.

Thanks to Tim Graham for the review.

1 files changed, 64 insertions, 0 deletions

diff --git a/django/urls/utils.py b/django/urls/utils.py
new file mode 100644
index 0000000000..1901c0a494
--- /dev/null
+++ b/django/urls/utils.py
@@ -0,0 +1,64 @@
+from __future__ import unicode_literals
+
+from importlib import import_module
+
+from django.core.exceptions import ViewDoesNotExist
+from django.utils import lru_cache, six
+from django.utils.module_loading import module_has_submodule
+
+
+@lru_cache.lru_cache(maxsize=None)
+def get_callable(lookup_view):
+    """
+    Return a callable corresponding to lookup_view.
+    * If lookup_view is already a callable, return it.
+    * If lookup_view is a string import path that can be resolved to a callable,
+      import that callable and return it, otherwise raise an exception
+      (ImportError or ViewDoesNotExist).
+    """
+    if callable(lookup_view):
+        return lookup_view
+
+    if not isinstance(lookup_view, six.string_types):
+        raise ViewDoesNotExist("'%s' is not a callable or a dot-notation path" % lookup_view)
+
+    mod_name, func_name = get_mod_func(lookup_view)
+    if not func_name:  # No '.' in lookup_view
+        raise ImportError("Could not import '%s'. The path must be fully qualified." % lookup_view)
+
+    try:
+        mod = import_module(mod_name)
+    except ImportError:
+        parentmod, submod = get_mod_func(mod_name)
+        if submod and not module_has_submodule(import_module(parentmod), submod):
+            raise ViewDoesNotExist(
+                "Could not import '%s'. Parent module %s does not exist." %
+                (lookup_view, mod_name)
+            )
+        else:
+            raise
+    else:
+        try:
+            view_func = getattr(mod, func_name)
+        except AttributeError:
+            raise ViewDoesNotExist(
+                "Could not import '%s'. View does not exist in module %s." %
+                (lookup_view, mod_name)
+            )
+        else:
+            if not callable(view_func):
+                raise ViewDoesNotExist(
+                    "Could not import '%s.%s'. View is not callable." %
+                    (mod_name, func_name)
+                )
+            return view_func
+
+
+def get_mod_func(callback):
+    # Convert 'django.views.news.stories.story_detail' to
+    # ['django.views.news.stories', 'story_detail']
+    try:
+        dot = callback.rindex('.')
+    except ValueError:
+        return callback, ''
+    return callback[:dot], callback[dot + 1:]