Rails Basics Application

Create new application

rails new application -d mysql --skip-test-unit

Other options Rails Basics

Application Directory

/application
  /app
      /assets
          /images           Image 
          /javascripts      JavaScript(CoffeeScript)
          /stylesheets      CSS(SCSS)
      /controllers          Controller class
          /concerns         Controller common module
          application_controller.rb     Application common controller    
      /helpers              View Helper
            application_heler.rb     Application common helper
      /mailers              ActionMailer
      /models               Model class
      /views                View script
         /layout                       layout
            application.html.erb       Application common layout
  /bin      Helper script
  /config   Config
      /environments
      /initializers
      /locales  
  /db
  /lib                Library by yourself
      /assets
  /log
  /public
  /test
  /tmp
  /vendor          3rd party codes
       /assets     3rd party assets
  config.ru        Application entry point
  Gemfile
  Rakefile
  README.rdoc

Controller

Details are Rails Controller
Controllers and Action are Rails Controller Action

rails g controller hello

What is created?

/application
  /app
    /assets
      /javascripts
        hello.js.coffee  (coffee)
      /stylesheets
        hello.css.scss  (scss)
    /controllers
       hello_controller.rb
    /views
       /hello      (erb)
    /helpers
       hello_helpers.rb  (helper)
  /test
    /controllers
      hello_controller_test.rb   (test_unit)
    /helpers  
      hello_helper_test.rb  (test_unit)

Clean controller

rails destroy controller controllername

Class

class HelloController < ApplicationController
end
&#91;/ruby&#93;
Output text
&#91;ruby&#93;
render text: ''
&#91;/ruby&#93;

<h4>Files naming rule</h4>
[bash]
rails g controller abc
[/bash]
<table>
<tr><th>Name</th><th>File name</th></tr>
<tr><td>class</td><td>ABCController</td></tr>
<tr><td>file</td><td>abc_controller.rb</td></tr>
<tr><td>helper</td><td>abc_helper.rb</td></tr>
<tr><td>test</td><td>abc_controller_test.rb</td></tr>
</table>

<hr>
<h3>Basic Route</h3>
config/routes.rb
[ruby]
action ':controller(/:action(:id))', via: [ :get, :post, :patch ]

This covers all controller/action (not for production)
Example) /hello/index

View

ERB
app/views/hello/index.html.erb
app/views/controllername/actionname.html.erb

<% %>
<%= @value %>

Model Basics

Details are following
Model Start Up
database setting is config/database.yml
Details are Database and check

Create model

rails g model book

Several files are created

/application
  /app
    /models
      book.rb     Model
  /db
    /migrate
     20141012132619_create_book.rb
  /test
    /models
       book_test.rb
    /fixtures
       book.yml       Fixture files for test

migration file is in db/migrate

Add type

Add db column in migration file

class CreateBooks < ActiveRecord::Migration
  def change
    create_table :books do |t|
      t.string :isbn
      t.string :title
      t.integer :price
      t.string :publish
      t.date :published
      t.boolean :cd
      t.timestamps
    end   
  end
end
&#91;/ruby&#93;

<h4>migration</h4>
[bash]
rake db:migrate
[/bash]

<h4>Check database</h4>
We can check database using dbconsole
[bash]
rails dbconsole
[/bash]
Open clinent using config/database.yml
In case of Sqlite3, open sqlite3

[bash]
sqlite>.tables
sqlite>.schema tablename
sqlite>.quit
[/bash]

<hr>
<h3>Simple Action and View</h3>
<h4>List Action</h4>
app/controllers/hello_controller.rb
[ruby]
def list
  @books = Book.all
end

View template
app/views/hello/list.html.erb

<table border="1">
  <tr>
   <th>Name</th><th>Price</th>
  </tr>
<%= @books.each do |book| %>
  <tr>
    <td><%= book.isbn %></td>
	<td><%= book.title %></td>
	<td><%= book.price %></td>
  </tr>
<% end %>
</table>