File: README.rdoc
| Path: | README.rdoc |
| Modified: | Fri Aug 06 10:45:21 -0400 2010 |
session_countdown
A Ruby on Rails plugin that puts a countdown timer on the session object.
session.countdown_start(1.hour)
session.countdown_count #=> 3600
session.countdown_running? # => true
# 60 minutes pass
session.countdown_count #=> 0
session.countdown_running? # => false
session.countdown_expired? # => true
session.countdown_restart
session.countdown_running? # => true
session.countdown_abort
session.countdown_running? # => false
session.countdown_expired? # => false
But why?!?
Sometimes I need to build my own custom rails authentication systems rather than use plugins such as Authlogic, Devise or restful_authentication.
There is always a "timer" in my custom authentication contraptions, and there is always a session object lurking when I‘m dealing with authentication stuff, so why not combine the two?
API
Note that countdown_abort(), countdown_restart() and countdown_count() will throw a NoCountdown exception if called on a non-existent countdown timer.
Start a countdown timer
session.countdown_start(seconds, name = :default)
You can have multiple countdown timers if you name them. The default countdown timer is named "default".
Check if a countdown timer exists and is currently running
session.countdown_running?(name = :default)
Expire early (i.e. logout)
session.countdown_abort(name = :default)
Restart, using the duration supplied to countdown_start
session.countdown_restart(name = :default)
Check if expired
session.countdown_expired?(name = :default)
Remaining time in seconds
session.countdown_count(name = :default)
Understanding timer running, expired, and never started
countdown_running? == true # timer running
countdown_expired? == true # timer expired
countdown_running? == false && countdown_expired? == false # never ran
Synopsis
In application_controller.rb
before_filter :authorize
def
if session.countdown_running?
session.countdown_restart # extend user's login
else
# store attempted access before rudely redirected to login screen
session[:original_uri] = request.request_uri # rails3 use request.fullpath
if session.countdown_expired?
flash[:notice] = "Login Expired"
else
flash[:notice] = "Please login"
end
redirect_to :login
end
end
In any controller
def login
user = User.find_by_email(params[:email)
if user && user.password_matches?(params[:password])
session.countdown_start(1.hour)
redirect_to :controller => :private
else
flash.now[:notice] = "Sorry, email/password wrong"
render :index
end
end
def logout
session.countdown_abort
flash[:notice] = "You are now logged out"
redirect_to :index
end
In user model
def before_save
if self.password_changed?
self.salt = SecureRandom.hex(10)
self.password = Digest::MD5.hexdigest(self.salt + self.password)
end
end
def password_matches?(password_to_match)
self.password == Digest::MD5.hexdigest(self.salt + password_to_match)
end
Note: Remember me
If you want an "remember me" feature you need to do two things.
Set timer for far future when user checks "remember me"
session.countdown_start(1.year)
Tell rails to serve up a persistent cookie instead of session cookie, probably in application_controller.rb
ActionController::Base.[:expire_after] = 1.year
Persistent vs session cookies
There are two types of browser cookies: ones with expiration dates and ones without. When a cookie doesnt have an expiration date it‘s a session cookie and will be deleted when the browser quits. If the cookie has an expiration date it‘s a persistent cookie (a.k.a. domain cookie) and will be valid until that date.
"Remember me" could work fine with only session cookies, provided the user never quits the browser, but users expect "remember me" to never expire their login and to persist across browser quits. It also makes sense to set a far future expiration date or the cookie will eventually expire before the login does.