Fix #110 -- Enable S3Input support for dummy storage

Author: codingjoe

README.rst

@@ -68,7 +68,8 @@ you do not need to alter your code at all.
 
 The ``ClearableFileInput`` widget is only than automatically replaced
 when the ``DEFAULT_FILE_STORAGE`` setting is set to
-``django-storages``\ ’ ``S3Boto3Storage``.
+``django-storages``\ ’ ``S3Boto3Storage`` or the dummy ``FileSystemStorage``
+is enabled.
 
 Setting up the AWS S3 bucket
 ----------------------------

s3file/apps.py

@@ -10,12 +10,12 @@ class S3FileConfig(AppConfig):
 
     def ready(self):
         from django import forms
-        from django.core.files.storage import default_storage
+        from django.core.files.storage import FileSystemStorage, default_storage
         from storages.backends.s3boto3 import S3Boto3Storage
 
         from .forms import S3FileInputMixin
 
-        if isinstance(default_storage, S3Boto3Storage) and \
+        if isinstance(default_storage, (S3Boto3Storage, FileSystemStorage)) and \
                 S3FileInputMixin not in forms.ClearableFileInput.__bases__:
             forms.ClearableFileInput.__bases__ = \
                 (S3FileInputMixin,) + forms.ClearableFileInput.__bases__