How do I set/get session vars in a Rack app?

ruby session rack
rebnoob picture rebnoob · May 4, 2012 · Viewed 13.7k times · Source 
use Rack::Session::Pool
...
session[:msg]="Hello Rack"

EDIT: The word session doesn't seem to resolve. I included the Session pool middleware in my config.ru, and try to set a variable in an ERB file (I'm using Ruby Serve) and it complains "undefined local variable or method `session'"

Thanks!

Answer

matt picture matt · May 4, 2012

session is a method that is part of some web frameworks, for example Sinatra and Rails both have session methods. Plain rack applications don’t have a session method, unless you add one yourself.

The session hash is stored in the rack env hash under the key rack.session, so you can access it like this (assuming you’ve named the rack environment to your app env):

env['rack.session'][:msg]="Hello Rack"

Alternatively, you could use Rack’s built in request object, like this:

request = Rack::Request.new(env)
request.session[:msg]="Hello Rack"

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