Handle login/logout.

Use a user_id cookie to store the login ID.  Added a global logout action.
Added users/login.

app/controllers/application.rb

 # Filters added to this controller will be run for all controllers in the application.
 # Likewise, all the methods added will be available for all controllers.
 class ApplicationController < ActionController::Base
+  def logout
+    cookies.delete :user_id
+    flash[:notice] = "You have been logged out"
+    redirect_to :controller => "users", :action => "login"
+  end
 end

app/controllers/recordings_controller.rb

@@ -13,10 +13,17 @@ class RecordingsController < ApplicationController
   end
 
   def list_owned
-    @owner = User.find(params[:user_id])
+    user_id = cookies[:user_id]
+    if user_id.nil?
+      logger.add(Logger::DEBUG, "No user_id cookie found")
+      redirect_to :controller => "users", :action => "login"
+      return
+    end
+
+    @owner = User.find(user_id)
     @recording_pages, @recordings = paginate :recordings, 
 	:per_page => 10,
-	:conditions => [ "(user_id = ? OR user_id IS NULL)", params[:user_id]],
+	:conditions => [ "(user_id = ? OR user_id IS NULL)", user_id],
 	:order => "updated_on"
   end
 

app/controllers/users_controller.rb

@@ -48,4 +48,25 @@ class UsersController < ApplicationController
     User.find(params[:id]).destroy
     redirect_to :action => 'list'
   end
+
+  def login
+
+    logger.add(Logger::DEBUG, "This is a log message!")
+
+    @user_pages, @users = paginate :users, :per_page => 10
+
+    if params[:id].nil?
+      return
+    end
+      
+    user = User.find(params[:id])
+    if user.nil?
+      flash.now[:notice] = "User id " + params[:id] + " not found"
+      return
+    end
+
+    cookies[:user_id] = params[:id]
+    flash[:notice] = "Welcome, " + user.username
+    redirect_to :controller => "recordings", :action => "list_owned"
+  end
 end

app/views/users/login.rhtml

+<h1>Login</h1>
+
+<p>Welcome!  Who are you?</p>
+
+<% for user in @users %>
+  <% form_for :user, @user do |f| %>
+    <input type="hidden" name="id" value="<%= user.id %>" />
+    <input type="submit" value="<%= user.username %>" />
+  <% end %>
+<% end %>
+
+<%= link_to 'Previous page', { :page => @user_pages.current.previous } if @user_pages.current.previous %>
+<%= link_to 'Next page', { :page => @user_pages.current.next } if @user_pages.current.next %> 
+
+<br />
+
+<%= link_to 'New user', :action => 'new' %>