From c48c720f8a7cfda47c46b38004d80921ab2ea305 Mon Sep 17 00:00:00 2001
From: Matthew Tretter <m@tthewwithanm.com>
Date: Fri, 15 Mar 2013 00:27:23 -0400
Subject: [PATCH] Add __nonzero__ method that will work for async

---
 imagekit/cachefiles/__init__.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/imagekit/cachefiles/__init__.py b/imagekit/cachefiles/__init__.py
index 24a77e3..c53a5ef 100644
--- a/imagekit/cachefiles/__init__.py
+++ b/imagekit/cachefiles/__init__.py
@@ -75,6 +75,15 @@ class ImageCacheFile(BaseIKFile, ImageFile):
                 )
             )
 
+    def __nonzero__(self):
+        if not self.name:
+            return False
+
+        # Dispatch the before_access signal before checking to see if the file
+        # exists. This gives the strategy a chance to create the file.
+        before_access.send(sender=self, file=self)
+        return self.cachefile_backend.exists(self)
+
 
 class LazyImageCacheFile(LazyObject):
     def __init__(self, generator_id, *args, **kwargs):