Add docs for serializer option #25

README.md

@@ -80,6 +80,27 @@ My::Application.config.session_store = :redis_session_store, {
 }
 ```
 
+### Serializer
+
+By default the Marshal serializer is used. With Rails 4, you can use JSON as a
+custom serializer:
+
+* `:json` - serialize cookie values with `JSON` (Requires Rails 4+)
+* `:marshal` - serialize cookie values with `Marshal` (Default)
+* `:hybrid` - transparently migrate existing `Marshal` cookie values to `JSON` (Requires Rails 4+)
+* `CustomClass` - You can just pass the constant name of any class that responds to `.load` and `.dump`
+
+``` ruby
+My::Application.config.session_store = :redis_session_store, {
+  # ... other options ...
+  serializer: :hybrid
+}
+```
+
+**Note**: Rails 4 is required for using the `:json` and `:hybrid` serializers
+because the `Flash` object doesn't serializer well in 3.2. See [Rails
+#13945](https://github.com/rails/rails/pull/13945) for more info.
+
 Contributing, Authors, & License
 --------------------------------
 

lib/redis-session-store.rb

@@ -16,6 +16,7 @@ class RedisSessionStore < ActionDispatch::Session::AbstractStore
   #   * +:expire_after+ - A number in seconds for session timeout
   # * +:on_sid_collision:+ - Called with SID string when generated SID collides
   # * +:on_redis_down:+ - Called with err, env, and SID on Errno::ECONNREFUSED
+  # * +:serializer:+ - Serializer to use on session data, default is :marshal.
   #
   # ==== Examples
   #
@@ -30,6 +31,7 @@ class RedisSessionStore < ActionDispatch::Session::AbstractStore
   #       },
   #       on_sid_collision: ->(sid) { logger.warn("SID collision! #{sid}") },
   #       on_redis_down: ->(*a) { logger.error("Redis down! #{a.inspect}") }
+  #       serializer: :hybrid # migrate from Marshal to JSON
   #     }
   #
   def initialize(app, options = {})