Improved `from_url()` support.

`from_url()` is now implemented as a classmethod.  The previous
implementation always returned instances of the `Redis` class.  This
new approach lets us construct StrictRedis instances (or any other
class derived from StrictRedis, including Redis).

`utils.from_url()` has been preserved for backwards compatibility.

Also, both versions of `from_url()` now pass along any additional
keyword arguments to the class's initializer.

2 files changed, 33 insertions, 24 deletions

diff --git a/redis/client.py b/redis/client.py
index d866928..3cca591 100644
--- a/redis/client.py
+++ b/redis/client.py
@@ -3,6 +3,7 @@ import datetime
 import time
 import warnings
 from itertools import imap, izip, starmap
+from urlparse import urlparse
 from redis.connection import ConnectionPool, UnixDomainSocketConnection
 from redis.exceptions import (
     ConnectionError,
@@ -184,6 +185,36 @@ class StrictRedis(object):
         }
         )
 
+    @classmethod
+    def from_url(cls, url, db=None, **kwargs):
+        """
+        Return a Redis client object configured from the given URL.
+
+        For example::
+
+            redis://username:password@localhost:6379/0
+
+        If ``db`` is None, this method will attempt to extract the database ID
+        from the URL path component.
+
+        Any additional keyword arguments will be passed along to the Redis
+        class's initializer.
+        """
+        url = urlparse(url)
+
+        # We only support redis:// schemes.
+        assert url.scheme == 'redis' or not url.scheme
+
+        # Extract the database ID from the path component if hasn't been given.
+        if db is None:
+            try:
+                db = int(url.path.replace('/', ''))
+            except (AttributeError, ValueError):
+                db = 0
+
+        return cls(host=url.hostname, port=url.port, db=db,
+                   password=url.password, **kwargs)
+
     def __init__(self, host='localhost', port=6379,
                  db=0, password=None, socket_timeout=None,
                  connection_pool=None, charset='utf-8',
diff --git a/redis/utils.py b/redis/utils.py
index 863541d..8e3b124 100644
--- a/redis/utils.py
+++ b/redis/utils.py
@@ -1,31 +1,9 @@
-from urlparse import urlparse
-
 from .client import Redis
 
-DEFAULT_DATABASE_ID = 0
-
-def from_url(url, db=None):
+def from_url(url, db=None, **kwargs):
     """Returns an active Redis client generated from the given database URL.
 
     Will attempt to extract the database id from the path url fragment, if
     none is provided.
     """
-
-    url = urlparse(url)
-
-    # Make sure it's a redis database.
-    if url.scheme:
-        assert url.scheme == 'redis'
-
-    # Attempt to resolve database id.
-    if db is None:
-        try:
-            db = int(url.path.replace('/', ''))
-        except (AttributeError, ValueError):
-            db = DEFAULT_DATABASE_ID
-
-    return Redis(
-        host=url.hostname,
-        port=url.port,
-        db=db,
-        password=url.password)
\ No newline at end of file
+    return Redis.from_url(url, db, **kwargs)