1 files changed, 60 insertions, 0 deletions
diff --git a/tools/storage.py b/tools/storage.py
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+++ b/tools/storage.py
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+# -*- coding: utf-8 -*-
+#
+# custom storage class
+# and storage related tools
+#
+
+from django.conf import settings
+from django.core.files.storage import FileSystemStorage
+from django.db.models.fields.files import FieldFile
+
+import os
+
+
+### OverwriteStorage ###
+class OverwriteStorage(FileSystemStorage):
+    """
+    overwrite original file before store the new one
+    """
+    def get_available_name(self, name):
+        """
+        Returns a filename that's free on the target storage system,
+        and available for new content to be written to.
+        Ref: http://djangosnippets.org/snippets/976/
+
+        This file storage solves overwrite on upload problem. Another
+        proposed solution was to override the save method on the model
+        like so (from https://code.djangoproject.com/ticket/11663):
+
+        def save(self, *args, **kwargs):
+            try:
+                this = MyModelName.objects.get(id=self.id)
+                if this.MyImageFieldName != self.MyImageFieldName:
+                    this.MyImageFieldName.delete()
+            except: pass
+            super(MyModelName, self).save(*args, **kwargs)
+        """
+        # If the filename already exists,
+        # remove it as if it was a true file system
+        if self.exists(name):
+            filepath = os.path.join(settings.MEDIA_ROOT, name)
+            if os.path.isfile(filepath):
+                os.remove(filepath)
+        return name
+
+
+### delete files associated with model FileField
+# Pre-delete signal function for deleting files a model
+# https://djangosnippets.org/snippets/2820/
+def file_cleanup(sender, instance, *args, **kwargs):
+    """
+    Deletes the file(s) associated with a model instance. The model
+    is not saved after deletion of the file(s) since this is meant
+    to be used with the pre_delete signal.
+    """
+    for field_name, _ in instance.__dict__.iteritems():
+        field = getattr(instance, field_name)
+        if (issubclass(field.__class__, FieldFile) and field.name):
+            # pass False so FileField does not save the model
+            field.delete(save=False)
+