Fixed #8641: Documented the fact that file-saving methods must receive a File instance

git-svn-id: http://code.djangoproject.com/svn/django/trunk@8759 bcc190cf-cafb-0310-a4f2-bffc1f526a37

docs/ref/files/file.txt

@@ -110,6 +110,9 @@ are the same as this one line::
 
     >>> car.photo.save('myphoto.jpg', contents, save=True)
 
+Note that the ``content`` argument must be an instance of
+:class:`File` or of a subclass of :class:`File`.
+
 ``File.delete(save=True)``
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 

docs/ref/files/storage.txt

@@ -42,6 +42,10 @@ If there already exists a file with this name ``name``, the storage system may
 modify the filename as necessary to get a unique name. The actual name of the
 stored file will be returned.
 
+The ``content`` argument must be an instance of
+:class:`django.db.files.File` or of a subclass of
+:class:`~django.db.files.File`.
+
 ``Storage.delete(name)``
 ~~~~~~~~~~~~~~~~~~~~~~~~
 

docs/topics/files.txt

@@ -96,8 +96,9 @@ You can create an instance of some custom file storage class, or -- often more
 useful -- you can use the global default storage system::
 
     >>> from django.core.files.storage import default_storage
+    >>> from django.core.files.base import ContentFile
 
-    >>> path = default_storage.save('/path/to/file', 'new content')
+    >>> path = default_storage.save('/path/to/file', ContentFile('new content'))
     >>> path
     u'/path/to/file'