Cookies syntax built into Rails

sessions_helper.rb

module SessionsHelper

  def sign_in(user)
    cookies.permanent[:remember_token] = user.remember_token
    self.current_user = user
  end
end

# You can use cookies as if it were a hash even though it's not as it's actually saves a piece of text on the bowser.
# Each element in the cookies is itself a hash of two elements, a value and an optional expires date.

cookies[:remember_token] = { value:   user.remember_token,
                             expires: 20.years.from_now.utc }

# This is same as using the permanent method where rails will automatically set 20.years.from_now:

cookies.permanent[:remember_token] = user.remember_token

# After the cookie is set, on subsequent page views we can retrieve the user with code like:

User.find_by_remember_token(cookies[:remember_token])