Google has a style guide for writing javascript. I think it’s great. Link

I’ve been looking at Rails examples for well over a year now. I’ve seen a lot of todo list examples, forum examples, and others. The one thing missing from these examples is authentication. I mean what kind of web app does not have authentication? Logging in / logging out and having other records attached to your user ID is a must for any real webapp.

In this tutorial I’ll show you how to build a todo list app, with authentication.

rails realtodo
cd realtodo
rake db:create

The act as authenticated plugin must be downloaded and installed first.

script/plugin install http://svn.techno-weenie.net/projects/plugins/acts_as_authenticated

More information on this plugin can be found here. http://wiki.rubyonrails.org/rails/pages/Acts_as_authenticated

Now using the new plugin generated the authentication

ruby script/generate authenticated user account

Add the AuthenticatedSystem to /app/controllers/application.rb

class ApplicationController < ActionController::Base helper :all # include all helpers, all the time include AuthenticatedSystem
And now our todo list. generated just like before.

script/generate scaffold Todo title:string body:text done:boolean due:datetime

We also need to add the user_id column to the Todo, we don’t do this in scaffolding so that we don’t have to removed user_id from all of the generated forms.

script/generate migration add_user_id_to_todo

edit the generated file /db/migrate/003_add_user_id_to_todo.rb

class AddUserIdToTodo < ActiveRecord::Migration def self.up add_column :todos, :user_id, :integer end def self.down remove_column :todos, :user_id end end

modify the todo.rb and user.rb files. We need to add the one to many relation

/app/models/todo.rb

class Todo < ActiveRecord::Base belongs_to :user end

/app/models/user.rb (Lots of stuff in this generated class, just add has_many :todos

class User < ActiveRecord::Base # Virtual attribute for the unencrypted password attr_accessor :pass has_many :todos
Change the todo controller so that login is required by adding
near the top of the controller.

/app/controllers/todos_controller.rb

class TodosController < ApplicationController before_filter :login_required

act_as_authenticated adds the curent_user object everywhere. This is great because we can just use it in our controller. We only want to show todo’s for each user, and other users should  not be able to see other users todos. To do this we need to change how todo are loaded and saved.

def index
#@todos = Todo.find(:all)
@todos = current_user.todos

def show
#@todo = Todo.find(params[:id])
@todo = current_user.todos.find(params[:id])

def new
#@todo = Todo.new
@todo = current_user.todos.create

def edit
#@todo = Todo.find(params[:id])
@todo = current_user.todos.find(params[:id])

def create
#@todo = Todo.new(params[:todo])
@todo = current_user.todos.create(params[:todo])

def update
#@todo = Todo.find(params[:id])
@todo = current_user.todos.find(params[:id])

def destroy
@todo = current_user.todos.find(params[:id])
@todo.destroy

With the controller created we now need an index page to link everything together.

delete the /public/index.html file

generate a new controller for the main page

script/generate controller Main

Define and index function on the main controller

  def index
end

and create a new view under views/main/index.rhtml

Todo lists

<% if current_user == :false %>
<%= link_to "Login",   {:controller => ‘account’, :action => ‘login’}%>

<%= link_to "Signup",  {:controller => ‘account’, :action => ‘signup’}%>
<% else %>
You are logged in as <%= current_user.login %>

<%= link_to "Todos", {:controller => ‘todos’, :action => ‘index’}%>

<%= link_to "Logout", {:controller => ‘account’, :action => ‘logout’}%>
<% end%>

Edit the account controller to return to the main index page by default

change every redirect_back_or_default(:controller => ‘/account’, :action => ‘index’) to
redirect_back_or_default(:controller => ‘/main’, :action => ‘index’)

add the following line to /config/routes.rb

 map.root :controller => “main”

from the command line
rake db:migrate
script/server

Thats it. Navigation between the todo lists and the index needs to be added, but we now have a complete working rails todo list webapp, with seperate todo lists for each user.

I’ve been meaning to try Rails 2.0.1, and I had some trouble finding an example. I did find this one, which is quite good.

I thought I would add one of my own. Here in five lines are the steps to create a basic todo list application in rails.

rails todo
cd todo
rake db:create:all
script/generate scaffold Todo title:string body:text done:boolean due:datetime
rake db:migrate

Then start the web server
script/server

Open your browser to http://localhost:3000/todos

You can now create, edit and Delete items. Wow. Not one SQL command.

This tutorial assumes the following:
ralis 2.0.1 installed
running mysql with no password for root at localhost.
(And it was also made on a Macbook OS X Leopard).