newforms-admin: Merged to [4939]

git-svn-id: http://code.djangoproject.com/svn/django/branches/newforms-admin@4940 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 32 insertions, 0 deletions

diff --git a/django/utils/encoding.py b/django/utils/encoding.py
new file mode 100644
index 0000000000..4774fb0d26
--- /dev/null
+++ b/django/utils/encoding.py
@@ -0,0 +1,32 @@
+from django.conf import settings
+from django.utils.functional import Promise
+
+def smart_unicode(s):
+    if isinstance(s, Promise):
+        # The input is the result of a gettext_lazy() call, or similar. It will
+        # already be encoded in DEFAULT_CHARSET on evaluation and we don't want
+        # to evaluate it until render time.
+        # FIXME: This isn't totally consistent, because it eventually returns a
+        # bytestring rather than a unicode object. It works wherever we use
+        # smart_unicode() at the moment. Fixing this requires work in the
+        # i18n internals.
+        return s
+    if not isinstance(s, basestring,):
+        if hasattr(s, '__unicode__'):
+            s = unicode(s)
+        else:
+            s = unicode(str(s), settings.DEFAULT_CHARSET)
+    elif not isinstance(s, unicode):
+        s = unicode(s, settings.DEFAULT_CHARSET)
+    return s
+
+class StrAndUnicode(object):
+    """
+    A class whose __str__ returns its __unicode__ as a bytestring
+    according to settings.DEFAULT_CHARSET.
+
+    Useful as a mix-in.
+    """
+    def __str__(self):
+        return self.__unicode__().encode(settings.DEFAULT_CHARSET)
+