Fixed #17896 -- Added file_hash method to CachedStaticFilesStorage to…

… be able to customize the way the hashed name of a file is created. Thanks to mkai for the initial patch.

django/contrib/staticfiles/storage.py

@@ -64,6 +64,17 @@ def __init__(self, *args, **kwargs):
                 compiled = re.compile(pattern)
                 self._patterns.setdefault(extension, []).append(compiled)
 
+    def file_hash(self, name, content=None):
+        """
+        Retuns a hash of the file with the given name and optional content.
+        """
+        if content is None:
+            return None
+        md5 = hashlib.md5()
+        for chunk in content.chunks():
+            md5.update(chunk)
+        return md5.hexdigest()[:12]
+
     def hashed_name(self, name, content=None):
         parsed_name = urlsplit(unquote(name))
         clean_name = parsed_name.path.strip()
@@ -78,13 +89,11 @@ def hashed_name(self, name, content=None):
                 return name
         path, filename = os.path.split(clean_name)
         root, ext = os.path.splitext(filename)
-        # Get the MD5 hash of the file
-        md5 = hashlib.md5()
-        for chunk in content.chunks():
-            md5.update(chunk)
-        md5sum = md5.hexdigest()[:12]
-        hashed_name = os.path.join(path, u"%s.%s%s" %
-                                   (root, md5sum, ext))
+        file_hash = self.file_hash(clean_name, content)
+        if file_hash is not None:
+            file_hash = u".%s" % file_hash
+        hashed_name = os.path.join(path, u"%s%s%s" %
+                                   (root, file_hash, ext))
         unparsed_name = list(parsed_name)
         unparsed_name[2] = hashed_name
         # Special casing for a @font-face hack, like url(myfont.eot?#iefix")

docs/ref/contrib/staticfiles.txt

@@ -348,6 +348,15 @@ CachedStaticFilesStorage
     :setting:`CACHES` setting named ``'staticfiles'``. It falls back to using
     the ``'default'`` cache backend.
 
+    .. method:: file_hash(name, content=None)
+
+    .. versionadded:: 1.5
+
+    The method that is used when creating the hashed name of a file.
+    Needs to return a hash for the given file name and content.
+    By default it calculates a MD5 hash from the content's chunks as
+    mentioned above.
+
 .. _`far future Expires headers`: http://developer.yahoo.com/performance/rules.html#expires
 .. _`@import`: http://www.w3.org/TR/CSS2/cascade.html#at-import
 .. _`url()`: http://www.w3.org/TR/CSS2/syndata.html#uri

tests/regressiontests/staticfiles_tests/storage.py

@@ -1,5 +1,6 @@
 from datetime import datetime
 from django.core.files import storage
+from django.contrib.staticfiles.storage import CachedStaticFilesStorage
 
 class DummyStorage(storage.Storage):
     """
@@ -17,3 +18,9 @@ def exists(self, name):
 
     def modified_time(self, name):
         return datetime.date(1970, 1, 1)
+
+
+class SimpleCachedStaticFilesStorage(CachedStaticFilesStorage):
+
+    def file_hash(self, name, content=None):
+        return 'deploy12345'

tests/regressiontests/staticfiles_tests/tests.py

@@ -10,7 +10,7 @@
 
 from django.template import loader, Context
 from django.conf import settings
-from django.core.cache.backends.base import BaseCache, CacheKeyWarning
+from django.core.cache.backends.base import BaseCache
 from django.core.exceptions import ImproperlyConfigured
 from django.core.files.storage import default_storage
 from django.core.management import call_command
@@ -515,6 +515,44 @@ def test_cache_key_memcache_validation(self):
         self.assertEqual(cache_key, 'staticfiles:e95bbc36387084582df2a70750d7b351')
 
 
+# we set DEBUG to False here since the template tag wouldn't work otherwise
+@override_settings(**dict(TEST_SETTINGS,
+    STATICFILES_STORAGE='regressiontests.staticfiles_tests.storage.SimpleCachedStaticFilesStorage',
+    DEBUG=False,
+))
+class TestCollectionSimpleCachedStorage(BaseCollectionTestCase,
+        BaseStaticFilesTestCase, TestCase):
+    """
+    Tests for the Cache busting storage
+    """
+    def cached_file_path(self, path):
+        fullpath = self.render_template(self.static_template_snippet(path))
+        return fullpath.replace(settings.STATIC_URL, '')
+
+    def test_template_tag_return(self):
+        """
+        Test the CachedStaticFilesStorage backend.
+        """
+        self.assertStaticRaises(ValueError,
+                                "does/not/exist.png",
+                                "/static/does/not/exist.png")
+        self.assertStaticRenders("test/file.txt",
+                                 "/static/test/file.deploy12345.txt")
+        self.assertStaticRenders("cached/styles.css",
+                                 "/static/cached/styles.deploy12345.css")
+        self.assertStaticRenders("path/",
+                                 "/static/path/")
+        self.assertStaticRenders("path/?query",
+                                 "/static/path/?query")
+
+    def test_template_tag_simple_content(self):
+        relpath = self.cached_file_path("cached/styles.css")
+        self.assertEqual(relpath, "cached/styles.deploy12345.css")
+        with storage.staticfiles_storage.open(relpath) as relfile:
+            content = relfile.read()
+            self.assertNotIn("cached/other.css", content)
+            self.assertIn("other.deploy12345.css", content)
+
 if sys.platform != 'win32':
 
     class TestCollectionLinks(CollectionTestCase, TestDefaults):