lib/authenticated_system.rb

     1module AuthenticatedSystem
     2  protected
     3    # Returns true or false if the user is logged in.
     4    # Preloads @current_user with the user model if they're logged in.
     5    def logged_in?
     6      current_user != :false
     7    end
     8
     9    # Accesses the current user from the session.  Set it to :false if login fails
    10    # so that future calls do not hit the database.
    11    def current_user
    12      @current_user ||= (login_from_session || login_from_basic_auth || login_from_cookie || :false)
    13    end
    14
    15    # Store the given user id in the session.
    16    def current_user=(new_user)
    17      session[:user_id] = (new_user.nil? || new_user.is_a?(Symbol)) ? nil : new_user.id
    18      @current_user = new_user || :false
    19    end
    20
    21    # Check if the user is authorized
    22    #
    23    # Override this method in your controllers if you want to restrict access
    24    # to only a few actions or if you want to check if the user
    25    # has the correct rights.
    26    #
    27    # Example:
    28    #
    29    #  # only allow nonbobs
    30    #  def authorized?
    31    #    current_user.login != "bob"
    32    #  end
    33    def authorized?
    34      logged_in?
    35    end
    36
    37    # Filter method to enforce a login requirement.
    38    #
    39    # To require logins for all actions, use this in your controllers:
    40    #
    41    #   before_filter :login_required
    42    #
    43    # To require logins for specific actions, use this in your controllers:
    44    #
    45    #   before_filter :login_required, :only => [ :edit, :update ]
    46    #
    47    # To skip this in a subclassed controller:
    48    #
    49    #   skip_before_filter :login_required
    50    #
    51    def login_required
    52      authorized? || access_denied
    53    end
    54
    55    # Redirect as appropriate when an access request fails.
    56    #
    57    # The default action is to redirect to the login screen.
    58    #
    59    # Override this method in your controllers if you want to have special
    60    # behavior in case the user is not authorized
    61    # to access the requested action.  For example, a popup window might
    62    # simply close itself.
    63    def access_denied
    64      respond_to do |format|
    65        format.html do
    66          store_location
    67          redirect_to new_session_path
    68        end
    69        format.any do
    70          request_http_basic_authentication 'Web Password'
    71        end
    72      end
    73    end
    74
    75    # Store the URI of the current request in the session.
    76    #
    77    # We can return to this location by calling #redirect_back_or_default.
    78    def store_location
    79      session[:return_to] = request.request_uri
    80    end
    81
    82    # Redirect to the URI stored by the most recent store_location call or
    83    # to the passed default.
    84    def redirect_back_or_default(default)
    85      redirect_to(session[:return_to] || default)
    86      session[:return_to] = nil
    87    end
    88
    89    # Inclusion hook to make #current_user and #logged_in?
    90    # available as ActionView helper methods.
    91    def self.included(base)
    92      base.send :helper_method, :current_user, :logged_in?
    93    end
    94
    95    # Called from #current_user.  First attempt to login by the user id stored in the session.
    96    def login_from_session
    97      self.current_user = User.find_by_id(session[:user_id]) if session[:user_id]
    98    end
    99
   100    # Called from #current_user.  Now, attempt to login by basic authentication information.
   101    def login_from_basic_auth
   102      authenticate_with_http_basic do |username, password|
   103        self.current_user = User.authenticate(username, password)
   104      end
   105    end
   106
   107    # Called from #current_user.  Finaly, attempt to login by an expiring token in the cookie.
   108    def login_from_cookie
   109      user = cookies[:auth_token] && User.find_by_remember_token(cookies[:auth_token])
   110      if user && user.remember_token?
   111        user.remember_me
   112        cookies[:auth_token] = { :value => user.remember_token, :expires => user.remember_token_expires_at }
   113        self.current_user = user
   114      end
   115    end
   116end