![Ruby
a = {}
a[:first] = 2
a[:things] = 3
a[:foo] = "bar"
b = {
:first => 2,
:things => 3,
:foo => "bar"
}
b[:first] # 2](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-6-320.jpg)
![Ruby
x = [1,4,5,2,5,8,10]
x.sort # returns a copy of x sorted
[1,2,4,5,5,8,10]
x.sort! # modifies self
x.map{ |i| i + 4 } # [5,6,8,9,9,12,14]
x.map! do |i|
i + 4
end # [5,6,8,9,9,12,14]](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-7-320.jpg)
![# app/models/post.rb
class Post < ActiveRecord::Base
has_many :comments
validates_presence_of :title
validates_format_of :title, :with => /ASLB.*z/
end
p = Post.new
p.save # false
p.errors.full_messages # ["Title can't be blank", "Title
is invalid"]
p.title = "SLB is the best"
p.save # true](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-36-320.jpg)
![# POST /posts
# POST /posts.xml
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.xml { render :xml => @post, :status
=> :created, :location => @post }
else
format.html { render :action => "new" }
format.xml { render :xml => @post.errors, :status
=> :unprocessable_entity }
end
end
end](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-40-320.jpg)
![# app/views/posts/edit.html.erb
<h1>Edit post</h1>
<%= form_for(@post) do |f| %>
<div class="field">
<%= f.label :title %><br />
# app/controllers/posts_controller.rb
<%= f.text_field :title %>
def edit </div>
@post = Post.find(params[:id]) <div class="field">
respond_to do |format| <%= f.label :body %><br />
format.html # edit.html.erb} <%= f.text_area :body %>
end </div>
<div class="actions">
end
<%= f.submit %>
</div>
<% end %>
<%= link_to 'Show', @post %> |
<%= link_to 'Back', posts_path %>](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-44-320.jpg)
![# config/routes.rb
Blog::Application.routes.draw do
resources :posts do
resources :comments, :only => [:create]
end
end
POST /posts/:post_id/comments
Limiting actions is always the best practice](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-52-320.jpg)
![# app/controllers/comments_controller.rb
class CommentsController < ApplicationController
def create
@post = Post.find(params[:post_id])
@comment = @post.comments.new(params[:comment])
respond_to do |format|
if @comment.save
format.html { redirect_to(@post }
else
format.html { render :template => "posts/
show.html.erb" }
end
end
end
end](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-53-320.jpg)
![# app/views/comments/_form.html.erb
<%= form_for [post,comment] do |f| %>
<div class="field">
<%= f.label :body %><br />
<%= f.text_area :body %>
<p><%= f.submit %></p>
</div>
<% end %>
Our HTML form
What needs to change?](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-55-320.jpg)
![# app/views/comments/_form.html.erb
<%= form_for [post,comment], :remote => true do |f| %>
<div class="field">
<%= f.label :body %><br />
<%= f.text_area :body %>
<p><%= f.submit %></p>
</div>
<% end %>
That’s it? Not yet!](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-56-320.jpg)
![# app/controllers/comments_controller.rb
class CommentsController < ApplicationController
def create
@post = Post.find(params[:post_id])
@comment = @post.comments.new(params[:comment])
respond_to do |format|
if @comment.save
format.html { redirect_to(@post, :notice => 'Comment was
successfully created.') }
format.js
else
format.html { render :action => "new" }
format.js
end
end
end
end](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-57-320.jpg)
![# app/views/comments/create.js.rjs
if @comment.new_record?
page.replace :new_comment,
:partial => "comments/form",
:locals => {
:post => @post,
:comment => @comment }
else
page.insert_html :bottom, :comments, :partial
=> "comments/comment", :object => @comment
page[:new_comment].reset
end](https://image.slidesharecdn.com/rubyonrailsatprompt11-110720061932-phpapp01/85/Ruby-on-Rails-at-PROMPT-ISEL-11-63-320.jpg)
Ruby on Rails at PROMPT ISEL '11
- 1. Web Development with Ruby On Rails Pedro Cunha
- 2. Ruby Yukihiro "Matz" Matsumoto Ruby is designed for programmer productivity and fun Created February 1993
- 3. Ruby Everything is an object Dynamic Typing true.class # TrueClass class Foo
 nil.class # NilClass def initialize(x, y)
 @x = x @y = y end end class Foo2 end Foo.new(2, Foo2.new)
- 4. Ruby class Foo class Bar # Parenthesis can be omitted # Use ! if you change self def method def method! puts "Hello World" end end # Use ? if you return a boolean # Default params def method? def method2(x = 2) end puts x end # Only conventions end # Operator overload def +(x) end end
- 5. Ruby "hello".class # String :hello.class # Symbol a = "Hello" b = "Hello" # Convention # Use string if you plan to a.equal? b # false compute text x = :hello # Use symbols if you want to y = :hello define or/and set a behaviour which is not x.equal? y # true expected to change
- 6. Ruby a = {} a[:first] = 2 a[:things] = 3 a[:foo] = "bar" b = { :first => 2, :things => 3, :foo => "bar" } b[:first] # 2
- 7. Ruby x = [1,4,5,2,5,8,10] x.sort # returns a copy of x sorted [1,2,4,5,5,8,10] x.sort! # modifies self x.map{ |i| i + 4 } # [5,6,8,9,9,12,14] x.map! do |i| i + 4 end # [5,6,8,9,9,12,14]
- 8. Ruby Monkey Patching class String def +() # override string default + operator end end “With great power comes great responsability” Uncle Ben, Amazing Spiderman nº1
- 10. Ruby on Rails Created by David Heinemeir Hansson • CEO at 37th Signals • Personal Project, 2004 Present • Rails 3.1 • Growing community
- 11. Ruby on Rails Convention vs Configuration MVC Architecture REST routing
- 13. • Don’t Repeat Yourself • Increased productivity through conventions. Ex.: following a pattern for foreign key columns. • Take advantage of singular and plural word meanings
- 14. MVC
- 15. RoR
- 17. CRUD REST ROUTES CREATE POST /posts READ GET /posts/1 UPDATE PUT /posts/1 DELETE DELETE /posts/1
- 18. # routes.rb Blog::Application.routes.draw do resources :posts end
- 20. pcunha:prompt$ rails new Blog -d mysql Blog /app /controllers /mailers /models /views /config database.yml /db /migrate Gemfile /public /javascripts /stylesheets
- 21. # config/database.yml development: adapter: sqlite3 database: db/development.sqlite3 test: adapter: sqlite3 database: db/test.sqlite3 production: adapter: sqlite3 database: db/production.sqlite3
- 22. development: adapter: mysql2 encoding: utf8 database: Blog_development username: root password: test: adapter: mysql2 encoding: utf8 database: Blog_test username: root password: production: adapter: mysql2 encoding: utf8 database: Blog_production username: root password: rails new with mysql option
- 23. pcunha:Blog$ rails server => Booting WEBrick => Rails 3.0.7 application starting in development on http://0.0.0.0:3000 => Call with -d to detach => Ctrl-C to shutdown server
- 24. localhost:3000
- 26. pcunha:Blog$ rails generate scaffold Post title:string body:text invoke active_record create db/migrate/20110715102126_create_posts.rb create app/models/post.rb invoke test_unit create test/unit/post_test.rb create test/fixtures/posts.yml 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
- 27. # config/db/migrate/20110715102126_create_posts.rb class CreatePosts < ActiveRecord::Migration def self.up create_table :posts do |t| t.string :title t.text :body t.timestamps end end def self.down drop_table :posts end end
- 28. pcunha:Blog$ rake db:create pcunha:Blog$ rake db:migrate == CreatePosts: migrating -- create_table(:posts) -> 0.0015s == CreatePosts: migrated (0.0018s)
- 29. pcunha:Blog$ rails generate model Comment body:text invoke active_record create db/migrate/20110715103725_create_comments.rb create app/models/comment.rb invoke test_unit create test/unit/comment_test.rb create test/fixtures/comments.yml pcunha:Blog$ rails generate migration AddPostIdToComments post_id:integer invoke active_record create db/migrate/20110715103834_add_post_id_to_comments.rb
- 30. # 20110715103834_add_post_id_to_comments.rb class AddPostIdToComments < ActiveRecord::Migration def self.up add_column :comments, :post_id, :integer end def self.down remove_column :comments, :post_id end end
- 31. pcunha:Blog$ rake db:migrate == CreateComments: migrating -- create_table(:comments) -> 0.0011s == CreateComments: migrated (0.0012s) == AddPostIdToComments: migrating -- add_column(:comments, :post_id, :integer) -> 0.0011s == AddPostIdToComments: migrated (0.0041s)
- 32. rake db:create rake db:migrate rake db:migrate:redo rake db:rollback blog_db.schema_migrations - keeps the version number of all migrations already runned
- 33. Model Relations
- 34. # app/models/post.rb class Post < ActiveRecord::Base has_many :comments end # app/models/comment.rb class Comment < ActiveRecord::Base belongs_to :post end Post.all Post.find(1).comments Comments.find(1).post Post.order(:created_at) Post.limit(5).offset(2)
- 36. # app/models/post.rb class Post < ActiveRecord::Base has_many :comments validates_presence_of :title validates_format_of :title, :with => /ASLB.*z/ end p = Post.new p.save # false p.errors.full_messages # ["Title can't be blank", "Title is invalid"] p.title = "SLB is the best" p.save # true
- 37. validates_presence_of :nif validates_format_of :name validates_acceptance_of :terms_and_conditions, :on => :create validates_numericality_of :age, :greater_than_or_equal_to => 18 validates_uniqueness_of :model_fk_key, :scope => :model_fk_key2 validates_length_of :minimum => 5
- 38. Controllers Managing the CRUD
- 39. # app/controllers/posts_controller.rb class PostsController < ApplicationController # GET /posts def index ... # GET /posts/1 def show ... # GET /posts/new def new ... # GET /posts/1/edit def edit ... # POST /posts def create ... # PUT /posts/1 def update ... # DELETE /posts/1 def destroy ... end Generated with scaffold
- 40. # POST /posts # POST /posts.xml 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.xml { render :xml => @post, :status => :created, :location => @post } else format.html { render :action => "new" } format.xml { render :xml => @post.errors, :status => :unprocessable_entity } end end end
- 41. def index @posts = Post.all respond_to do |format| format.html # index.html.erb format.xml { render :xml => @posts } end end pcunha:Blog$ curl http://localhost:3000/posts.xml <?xml version="1.0" encoding="UTF-8"?> <posts type="array"> <post> <created-at type="datetime">2011-07-15T13:39:51Z</created-at> <body>This is the body of the first post</body> <title>The first very post of this blog</title> <updated-at type="datetime">2011-07-15T13:39:51Z</updated-at> <id type="integer">1</id> </post> </posts>
- 42. Views
- 43. # app/views/posts/new.html.erb <h1>New post</h1> <%= form_for(@post) do |f| %> # app/controllers/posts_controller.rb def new <div class="field"> @post = Post.new <%= f.label :title %><br /> respond_to do |format| <%= f.text_field :title %> format.html # new.html.erb} </div> end <div class="field"> <%= f.label :body %><br /> end <%= f.text_area :body %> </div> <div class="actions"> <%= f.submit %> </div> <% end %> <%= link_to 'Back', posts_path %>
- 44. # app/views/posts/edit.html.erb <h1>Edit post</h1> <%= form_for(@post) do |f| %> <div class="field"> <%= f.label :title %><br /> # app/controllers/posts_controller.rb <%= f.text_field :title %> def edit </div> @post = Post.find(params[:id]) <div class="field"> respond_to do |format| <%= f.label :body %><br /> format.html # edit.html.erb} <%= f.text_area :body %> end </div> <div class="actions"> end <%= f.submit %> </div> <% end %> <%= link_to 'Show', @post %> | <%= link_to 'Back', posts_path %>
- 45. Rails builds the route for you link_to 'Show', @post # GET posts/@post.id form_for(@post) if @post.new_record? POST /posts else PUT /posts/@post.id end
- 46. Views Partials
- 47. # app/views/posts/new.html.erb # app/views/posts/edit.html.erb <h1>New post</h1> <h1>Edit post</h1> <%= form_for(@post) do |f| %> <%= form_for(@post) do |f| %> <div class="field"> <div class="field"> <%= f.label :title %><br /> <%= f.label :title %><br /> <%= f.text_field :title %> <%= f.text_field :title %> </div> </div> <div class="field"> <div class="field"> <%= f.label :body %><br /> <%= f.label :body %><br /> <%= f.text_area :body %> <%= f.text_area :body %> </div> </div> <div class="actions"> <div class="actions"> <%= f.submit %> <%= f.submit %> </div> </div> <% end %> <% end %> <%= link_to 'Back', posts_path %> <%= link_to 'Show', @post %> | <%= link_to 'Back', posts_path %> Bad pattern
- 48. # app/views/posts/_form.html.erb # app/views/posts/new.html.erb <%= form_for(@post) do |f| %> <h1>New post</h1> <div class="field"> <%= render "form" %>%> <%= f.label :title %><br /> <%= link_to 'Back', posts_path %> <%= f.text_field :title %> </div> <div class="field"> <%= f.label :body %><br /> # app/views/posts/edit.html.erb <%= f.text_area :body %> <h1>Edit post</h1> </div> <div class="actions"> <%= render "form" %>%> <%= f.submit %> <%= link_to 'Show', @post %> | </div> <%= link_to 'Back', posts_path %> <% end %> The right way
- 50. Improve user experience by not having the whole page reload when submitting a form or simple pagination link Also save resources used (SQL queries, memory, more bandwidth usage,... etc)
- 51. AJAX Changing default forms to AJAX
- 52. # config/routes.rb Blog::Application.routes.draw do resources :posts do resources :comments, :only => [:create] end end POST /posts/:post_id/comments Limiting actions is always the best practice
- 53. # app/controllers/comments_controller.rb class CommentsController < ApplicationController def create @post = Post.find(params[:post_id]) @comment = @post.comments.new(params[:comment]) respond_to do |format| if @comment.save format.html { redirect_to(@post } else format.html { render :template => "posts/ show.html.erb" } end end end end
- 54. # app/views/posts/show.html.erb ... <h1>Comments</h1> <div id="comments"> <%= render :partial => "comments/comment", :collection => @post.commments %> </div> <%= render :partial => "comments/form", :locals => { :post => @post, :comment => @comment || Comment.new } %>
- 55. # app/views/comments/_form.html.erb <%= form_for [post,comment] do |f| %> <div class="field"> <%= f.label :body %><br /> <%= f.text_area :body %> <p><%= f.submit %></p> </div> <% end %> Our HTML form What needs to change?
- 56. # app/views/comments/_form.html.erb <%= form_for [post,comment], :remote => true do |f| %> <div class="field"> <%= f.label :body %><br /> <%= f.text_area :body %> <p><%= f.submit %></p> </div> <% end %> That’s it? Not yet!
- 57. # app/controllers/comments_controller.rb class CommentsController < ApplicationController def create @post = Post.find(params[:post_id]) @comment = @post.comments.new(params[:comment]) respond_to do |format| if @comment.save format.html { redirect_to(@post, :notice => 'Comment was successfully created.') } format.js else format.html { render :action => "new" } format.js end end end end
- 58. # app/views/comments/create.js.erb //Dump javascript here! document.getElementById... Notice: - create.js.erb - writing native javascript is not optimal: 1. You will forget something about IE 2. We are at 21st Century 3. Lots of good frameworks
- 59. Rails 2.X and 3.0.X - Prototype JS Framework as default Rails 3.1 (released 2011) - jQuery JS Framework as default
- 60. # app/views/comments/create.js.erb <% if @comment.new_record? %> <% content = render(:partial => "comments/form", :locals => { :post => @post, :comment => @comment }) content = escape_javascript(content) %> $('new_comment').replace("<%= content %>"); <% else %> <% comment_content = render(:partial => "comments/comment", :object => @comment) comment_content = escape_javascript(comment_content) %> $('comments').insert({ bottom : '<%= comment_content %>' }) $('new_comment').reset(); <% end %>
- 61. Almost there... but - Complex code - We can do better with Rails
- 62. RJS Ruby (to) JavaScript Templates
- 63. # app/views/comments/create.js.rjs if @comment.new_record? page.replace :new_comment, :partial => "comments/form", :locals => { :post => @post, :comment => @comment } else page.insert_html :bottom, :comments, :partial => "comments/comment", :object => @comment page[:new_comment].reset end
- 64. Gems
- 65. Gems Extend Rails framework Easy installation and usage Increasing community • Github • Gemcutter
- 66. Bundler gem # Gemfile gem "rails", "2.3.10" gem "will_paginate" gem "authlogic" gem "pg" gem "postgis_adapter", "0.7.8" gem "GeoRuby", "1.3.4" # Sphinx gem "thinking-sphinx", "1.4.5" group :development do gem "capistrano" gem "capistrano-ext" gem "ruby-debug" gem "wirble" gem "mongrel" end
- 67. Questions ?
- 69. References
- 70. Thanks :) [email protected] @mryise