Rails Pocket Reference

Real World Example: Honey-Do Task List

Just to get our feet wet in the Rails/Ajax world, let’s create a simple application that will manage our honey-do tasks. What we want to achieve is to be able to dynamically add and remove tasks, all using Scriptaculous and Prototype. Let’s get started.

1. Create a new Rails application called “honey-do”:

   rails honey-do

2. Now let’s create the Task model with some fields:

   ./script/generate model Task name:string priority:integer 
     completed:boolean

   Run the rake command to generate the database, then the command to run the migrations:

   rake db:create   # This is necessary only if the db isn't 
                    # created and you are not using SQLite3
   rake db:migrate

3. Create the Tasks controller:

   ./script/generate controller tasks

4. Now that we have the infrastructure in place, let’s start adding some code. First, let’s add some methods to the Task model and give it a validator:

   # app/models/task.rb
   
   class Task < ActiveRecord::Base
     
     validates_length_of :name, :minimum => 3, 
                         :message => 
                          "must be at least 3 characters long"
     
     # This is our list of available priorities.
     def self.priorities
       %w(1 2 3 4 5)
     end
     
     # Helper method to get open tasks sorted by priority
     def self.open_tasks
       Task.find(:all, :order => [:priority], :conditions =>  
        ["completed = ?", false])
     end
     
   end

   Note that our Task model requires that the length of the name is at least three characters. We also created two static helper methods.

5. Now let’s take a look at the controller:

   # app/controllers/tasks_controller.rb class TasksController ...