This document provides an overview of using scaffolding and basic CRUD functionality in Ruby on Rails. It demonstrates generating a Post resource using scaffolding, running migrations to create the database tables, using the generated controller actions and views to list, create, show, edit and delete posts. It also discusses using the console, adding validations, and connecting the application to a remote Git repository.

1. ROR Lab. Season 2
- The 2nd Round -
Getting Started
with Rails (2)
July 7, 2012
Hyoseong Choi
ROR Lab.

2. A Blog Project
Post
ny
on
a
m
separate form nested form
e
to form_for
to
ne
m
an
o
y
Comment Tag
form_for fields_for
ROR Lab.

3. Using Scaffolding
$ rails generate scaffold Post
name:string title:string content:text
Scaffolding Generator • MVC
• asset
• helper
• test unit
• routing
ROR Lab.

4. Creating
a Resource w scaffolding
$ rails g scaffold post name title content:text
invoke active_record
create db/migrate/20120705045702_create_posts.rb
create app/models/post.rb
invoke test_unit
create test/unit/post_test.rb
create test/fixtures/posts.yml
invoke resource_route
route resources :posts
invoke scaffold_controller
create app/controllers/posts_controller.rb
invoke erb
create app/views/posts
create app/views/posts/index.html.erb
create app/views/posts/edit.html.erb
create app/views/posts/show.html.erb
create app/views/posts/new.html.erb
create app/views/posts/_form.html.erb
invoke test_unit
create test/functional/posts_controller_test.rb
invoke helper
create app/helpers/posts_helper.rb
invoke test_unit
create test/unit/helpers/posts_helper_test.rb
invoke assets
invoke coffee
create app/assets/javascripts/posts.js.coffee
invoke scss
create app/assets/stylesheets/posts.css.scss
invoke scss
create app/assets/stylesheets/scaffolds.css.scss
ROR Lab.

5. Running
a Migration
class CreatePosts < ActiveRecord::Migration
def change
create_table :posts do |t|
t.string :name
t.string :title
t.text :content
t.timestamps
end
end
end db/migrate/20100207214725_create_posts.rb
ROR Lab.

6. Running
a Migration
$ rake db:migrate
== CreatePosts: migrating
=========================================
===========
-- create_table(:posts)
-> 0.0019s
== CreatePosts: migrated (0.0020s)
to Where?
ROR Lab.

7. Adding a Link
<h1>Hello, Rails!</h1>
<%= link_to "My Blog", posts_path %>
app/views/home/index.html.erb
Hello, Rails!
My Blog
ROR Lab.

8. The Model
class Post < ActiveRecord::Base
attr_accessible :content, :name, :title
end
app/models/post.rb
Rails Active
Model Record
database.yml
ROR Lab.

9. Adding Validations
class Post < ActiveRecord::Base
attr_accessible :content, :name, :title
validates :name, :presence => true
validates :title, :presence => true,
:length => { :minimum => 5 }
end app/models/post.rb
app/models/post.rb
ROR Lab.

10. Using the Console
$ rails console --sandbox
$ rails c --sandbox
Loading development environment in sandbox (Rails
3.2.6)
Any modifications you make will be rolled back on exit
1.9.3p194 :001 > Post.all
Post Load (0.1ms) SELECT "posts".* FROM "posts"
=> []
1.9.3p194 :002 > reload!
Reloading...
=> true
ROR Lab.

11. Listing All Posts
def index
@posts = Post.all
respond_to do |format|
format.html # index.html.erb
format.json { render :json => @posts }
end
end
app/controllers/posts_controller.rb
1.9.3p194 :004 > posts = Post.all
Post Load (0.2ms) SELECT "posts".* FROM "posts"
=> []
1.9.3p194 :005 > posts.class
=> Array
1.9.3p194 :006 > post = Post.scoped
Post Load (0.2ms) SELECT "posts".* FROM "posts"
=> []
1.9.3p194 :007 > post.class
=> ActiveRecord::Relation
ROR Lab.

12. <h1>Listing posts</h1> Rails makes all of the
<table> instance variables from the
<tr> action available to the view.
<th>Name</th>
<th>Title</th>
<th>Content</th>
<th></th>
<th></th>
<th></th>
</tr>
<% @posts.each do |post| %>
<tr>
<td><%= post.name %></td>
<td><%= post.title %></td>
<td><%= post.content %></td>
<td><%= link_to 'Show', post %></td>
<td><%= link_to 'Edit', edit_post_path(post) %></td>
<td><%= link_to 'Destroy', post, :confirm => 'Are you sure?',
:method => :delete %></td>
</tr>
<% end %>
</table>
<br />
<%= link_to 'New post', new_post_path %>
app/views/posts/index.html.erb
ROR Lab.

13. The Layout
: Containers for views
<!DOCTYPE html>
<html>
<head>
<title>Blog</title>
<%= stylesheet_link_tag "application" %>
<%= javascript_include_tag "application" %>
<%= csrf_meta_tags %>
</head>
<body style="background: #EEEEEE;">
<%= yield %>
</body>
app/views/layouts/application.html.erb
ROR Lab.

14. Creating New Posts
def new
@post = Post.new
respond_to do |format|
format.html # new.html.erb
format.json { render :json => @post }
end
end
<h1>New post</h1>
<%= render 'form' %> # using HTTP POST verb
<%= link_to 'Back', posts_path %>
app/views/posts/new.html.erb
ROR Lab.

15. <%= form_for(@post) do |f| %>
<% if @post.errors.any? %>
<div id="errorExplanation">
<h2><%= pluralize(@post.errors.count, "error") %> prohibited
this post from being saved:</h2>
<ul>
<% @post.errors.full_messages.each do |msg| %>
<li><%= msg %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="field">
<%= f.label :name %><br />
<%= f.text_field :name %>
</div>
<div class="field">
<%= f.label :title %><br />
<%= f.text_field :title %>
</div>
<div class="field">
<%= f.label :content %><br />
<%= f.text_area :content %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %> a “Partial” template
app/views/posts/_form.html.erb
ROR Lab.
intelligent submit helper

16. ROR Lab.

17. “create” action
ROR Lab.

18. def create
@post = Post.new(params[:post])
respond_to do |format|
if @post.save
format.html { redirect_to(@post,
:notice => 'Post was successfully created.') }
format.json { render :json => @post,
:status => :created, :location => @post }
else
format.html { render :action => "new" }
format.json { render :json => @post.errors,
:status => :unprocessable_entity }
end
end
end
ROR Lab.

19. Show a Post
http://localhost:3000/posts/1
def show
@post = Post.find(params[:id])
respond_to do |format|
format.html # show.html.erb
format.json { render :json => @post }
end
end
ROR Lab.

20. Show a Post
app/views/posts/show.html.erb
<p id="notice"><%= notice %></p>
<p>
<b>Name:</b>
<%= @post.name %>
</p>
<p>
<b>Title:</b>
<%= @post.title %>
</p>
<p>
<b>Content:</b>
<%= @post.content %>
</p>
<%= link_to 'Edit', edit_post_path(@post) %> |
<%= link_to 'Back', posts_path %>
ROR Lab.

21. Editing Posts
def edit
@post = Post.find(params[:id])
<h1>Editing post</h1>
<%= render 'form' %> # using HTTP PUT verb
<%= link_to 'Show', @post %> |
<%= link_to 'Back', posts_path %>
app/views/posts/edit.html.erb
ROR Lab.

22. Editing Posts
def update
@post = Post.find(params[:id])
respond_to do |format|
if @post.update_attributes(params[:post])
format.html { redirect_to(@post,
:notice => 'Post was successfully updated.') }
format.json { head :no_content }
else
format.html { render :action => "edit" }
format.json { render :json => @post.errors,
:status => :unprocessable_entity }
end
end
end
ROR Lab.

23. Destroying a Post
def destroy
@post = Post.find(params[:id])
@post.destroy
respond_to do |format|
format.html { redirect_to posts_url }
format.json { head :no_content }
end
ROR Lab.

24. Git
• Linus Tobalds, 1991
• for source code version control
• local repository
ROR Lab.

25. Gitosis
• Remote repository
• git clone git://eagain.net/gitosis.git
• git clone git://github.com/res0nat0r/
gitosis.git
• Ubuntu 11.10 -> gitosis package
• Ubuntu 12.04 -> not any more but gitolite
ROR Lab.

26. Gitosis
• Remote repository
• git clone git://eagain.net/gitosis.git
• git clone git://github.com/res0nat0r/
gitosis.git
• Ubuntu 11.10 -> gitosis package
• Ubuntu 12.04 -> not any more but gitolite
ROR Lab.

27. Local Machine Git Repository Sever
git@gitserver:project.git
gitosis
gitolite
gitorious
$ git add *
$ git commit
$ git push Origin
ROR Lab.

28. 감사합니다.

29.
ROR Lab.