Ruby Rail First Step

• Your first application with MySQL

Create the Application

rails new firstapp -d mysql

1. Move into the application directory

cd firstapp

1. If you setup MySQL or Postgres with a username/password, modify the
2. config/database.yml file to contain the username/password that you specified

1. Create the database

rake db:create

1. Start the server

rails server

1. Visite the web site

http://localhost:3000

1. change the default page

Add the following into config/routes.rb

root :to => "home#index"

Start to Work with Resources

Generate a resource (Post)

rails generate scaffold Post name:string title:string content:text

Creating and Customizing Rails Generators & Templates

Create Tables (posts)

rake db:migrate

• To create in production

rake db:migrate RAILS_ENV=production.

Add a link into the home page

• Add Post Page in the index file app/view/home/index.html.erb

<%= link_to "My Blog", posts_path %> 

Add validation

• Add validation into app/modles/post.rb

class Post < ActiveRecord::Base
  validates :name,  :presence => true
  validates :title, :presence => true,
                    :length => { :minimum => 5 }
end

Create an Xml List

• Modify the sectioni def index of the file app/controllers/posts_controller.rb

def index
  @posts = Post.all
 
  respond_to do |format|
    format.html # index.html.erb
    format.xml  { render :xml => @posts }
  end
end

• Now try http://localhost:3000/posts.xml
• More information at Active Record Query Interface

Creation Process

New Post Request

• the form is empty but has the same feild a the one used for modification
• Inside the file app/controllers/posts_controller.rb

  def new
    @post = Post.new
  end

Empty Form

• app/view/new.html.erb

New post
<%= render 'form' %>
<%= link_to 'Back', posts_path %>