1. Desenvolvimento
Web com Ruby on
Rails
João Lucas Pereira de Santana
gtalk | linkedin | twitter: jlucasps
Extras

2. Extras
@jlucasps
$ git add .
$ git commit -m "Configurando o Devise"
Criar rotas para BillsController#new
match 'new_bill' => 'bills#new', :as => :new_bill
match 'create_bill' => 'bills#create_bill', :as => :create_bill
Criar action
def new
@bill = Bill.new
@users = User.all
end

3. Extras
@jlucasps
Alterar template /app/views/welcome/index.html.erb
<div class="span9">
<% label = "<i class='icon-user'></i>&nbsp;#{t('users')}".html_safe
%>
<%= link_to label, users_path, :class => "btn btn-large" %>
<%= link_to t('new_bill'), new_bill_path, :class => "btn btn-
large btn-success" %>
</div>
<%= content_for :sidebar do %>
<%= render :partial => 'shared/sidebar' %>
<% end %>

4. Extras
@jlucasps
Criar template /app/views/bills/new.html.erb
<h4><%= t('new_bill') %></h4>
<%= form_tag(create_bill_path) do %>
<%= render :partial => 'shared/error_messages' , :locals => {:resource => @bill} %>
<%= label_tag :user_id %>
<%= select_tag :user_id, options_from_collection_for_select(@users, :id, :name, @bill.
user_id) %>
<%= label_tag :name %>
<%= text_field_tag :name, @bill.name %>
<%= label_tag :description %>
<%= text_field_tag :description, @bill.description %>
<%= label_tag :date %>
<%= text_field_tag :date, @bill.date %>
<%= label_tag :value %>
<%= text_field_tag :value, @bill.value %>
<div class='actions'>
<%= submit_tag t('save'), :class => 'btn btn-success' %>
</div>
<% end %>

5. Extras
@jlucasps
Criar a action BillsController#create_bill
def create_bill
@bill = Bill.new(:user_id => params[:user_id], :name =>
params[:name])
@bill.description = params[:description]
@bill.date = params[:date]
@bill.value = params[:value]
if @bill.save
redirect_to @bill.user
else
@users = User.all
render :new
end
end

6. Extras
@jlucasps
Criar uma migration para a tabela comments
class CreateTableComments < ActiveRecord::
Migration
def change
create_table :comments do |t|
t.references :bill, :foreign_key => true
t.column :content, :string, :null => false
t.timestamps
end
end
end

7. Extras
@jlucasps
Executar migration
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rake db:
migrate
== CreateTableComments: migrating
==========================================
==
-- create_table(:comments)
-> 0.0670s
== CreateTableComments: migrated (0.0672s)
===================================

8. Extras
@jlucasps
Criar model Comment: /app/models/comment.rb
class Comment < ActiveRecord::Base
# Attrs accessible
attr_accessible :content, :bill_id
# Validations
validates :content, :presence => true, :allow_blank => false
validates :bill_id, :presence => true
# Associations
belongs_to :bill
# Scopes
default_scope order("comments.created_at DESC")
# Públic methods
end

9. Extras
@jlucasps
Alterar model Bill para adicionar relacionamento
class Bill < ActiveRecord::Base
# Attrs accessible
attr_accessible :name, :description, :user_id, :date, :value
# Validations
validates :name, :presence => true, :allow_blank => false
validates :user_id, :presence => true
validates :date, :presence => true
validates :value, :presence => true
# Associations
belongs_to :user
has_many :comments
...
end

10. Extras
@jlucasps
irb(main):002:0> bill = Bill.first
Bill Load (0.5ms) SELECT "bills".* FROM "bills" ORDER BY bills.date
DESC LIMIT 1
=> #<Bill id: 15, name: "123", description: "45", user_id: 9, date:
"2013-06-12 00:00:00", value: #<BigDecimal:3bc4e60,'0.124E3',9(36)
>, created_at: "2013-06-19 01:17:36", updated_at: "2013-06-19 01:17:
36">
irb(main):003:0> comment = Comment.new :bill_id => bill.id, :
content => "Conteúdo do comentário"
=> #<Comment id: nil, bill_id: 15, content: "Conteúdo do comentário",
created_at: nil, updated_at: nil>
irb(main):004:0> comment.save
(0.1ms) begin transaction
SQL (43.4ms) INSERT INTO "comments" ("bill_id", "content",
"created_at", "updated_at") VALUES (?, ?, ?, ?) [["bill_id", 15],
["content", "Conteúdo do comentário"], ["created_at", Tue, 25 Jun 2013
14:30:13 UTC +00:00], ["updated_at", Tue, 25 Jun 2013 14:30:13 UTC
+00:00]]
(393.4ms) commit transaction

11. Extras
@jlucasps
irb(main):005:0> bill.comments
Comment Load (0.4ms) SELECT "comments".* FROM "comments"
WHERE "comments"."bill_id" = 15 ORDER BY comments.created_at
DESC
=> [#<Comment id: 1, bill_id: 15, content: "Conteúdo do comentário",
created_at: "2013-06-25 14:30:13", updated_at: "2013-06-25 14:30:
13">]
irb(main):006:0> bill.comments.count
(0.3ms) SELECT COUNT(*) FROM "comments" WHERE "comments"."
bill_id" = 15
=> 1
irb(main):007:0> comment.bill
Bill Load (0.4ms) SELECT "bills".* FROM "bills" WHERE "bills"."id" = 15
ORDER BY bills.date DESC LIMIT 1
=> #<Bill id: 15, name: "123", description: "45", user_id: 9, date:
"2013-06-12 00:00:00", value: #<BigDecimal:42d7f68,'0.124E3',9(36)
>, created_at: "2013-06-19 01:17:36", updated_at: "2013-06-19 01:
17:36">
irb(main):008:0>

12. Extras
@jlucasps
E se quisermos adicionar comentários em outras entidades ?
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rails g migration
ChangeCommentsTable
invoke active_record
create db/migrate/20130625143912_change_comments_table.rb
class ChangeCommentsTable < ActiveRecord::Migration
def up
add_column :comments, :commentable_id, :integer
add_column :comments, :commentable_type, :string
remove_column :comments, :bill_id
end
def down
remove_column :comments, :commentable_id
remove_column :comments, :commentable_type
add_column :comments, :bill_id, :integer
end
end

13. Extras
@jlucasps
class Comment < ActiveRecord::Base
# Attrs accessible
attr_accessible :content, :bill_id
# Validations
validates :content, :presence => true, :allow_blank => false
validates :commentable_id, :presence => true
validates :commentable_type, :presence => true
# Associations
belongs_to :commentable, :polymorphic => true
# Scopes
default_scope order("comments.created_at DESC")
end
/app/models/comment.rb

14. Extras
@jlucasps
# Associations
belongs_to :user
has_many :comments, :as => :commentable
/app/models/bill.rb
/app/models/user.rb
# Associations
has_many :bills, :dependent => :destroy
has_many :comments, :as => :commentable

15. Extras
@jlucasps
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rails
console
Loading development environment (Rails 3.2.13)
irb(main):002:0> user = User.last
User Load (0.4ms) SELECT "users".* FROM "users" ORDER BY "users"."
id" DESC LIMIT 1
=> #<User id: 11, name: "teste100@teste.com", email:
"teste100@teste.com", age: nil, created_at: "2013-06-25 01:27:25",
updated_at: "2013-06-25 01:27:25", gender: nil, encrypted_password:
"$2a$10$hMAd4RUymIzxw1JGARKJC.M1hEiAwD0PpwS6uwM9j2RR...",
reset_password_token: nil, reset_password_sent_at: nil,
remember_created_at: nil, sign_in_count: 1, current_sign_in_at: "2013-
06-25 01:27:25", last_sign_in_at: "2013-06-25 01:27:25",
current_sign_in_ip: "127.0.0.1", last_sign_in_ip: "127.0.0.1">
irb(main):003:0> user.comments
Comment Load (0.2ms) SELECT "comments".* FROM "comments"
WHERE "comments"."commentable_id" = 11 AND "comments"."
commentable_type" = 'User' ORDER BY comments.created_at DESC
=> []
irb(main):004:0>

16. Extras
@jlucasps
irb(main):003:0> comment = Comment.new :content =>
"Comentário para um usuário"
=> #<Comment id: nil, content: "Comentário para um usuário",
created_at: nil, updated_at: nil, commentable_id: nil, commentable_type:
nil>
irb(main):004:0> comment.commentable = user
=> #<User id: 11, name: "teste100@teste.com", email: "teste100@teste.com", age: nil,
created_at: "2013-06-25 01:27:25", updated_at: "2013-06-25 01:27:25", gender: nil,
encrypted_password: "$2a$10$hMAd4RUymIzxw1JGARKJC.M1hEiAwD0PpwS6uwM9j2RR...",
reset_password_token: nil, reset_password_sent_at: nil, remember_created_at: nil,
sign_in_count: 1, current_sign_in_at: "2013-06-25 01:27:25", last_sign_in_at: "2013-06-25
01:27:25", current_sign_in_ip: "127.0.0.1", last_sign_in_ip: "127.0.0.1">
irb(main):005:0> comment.save
(0.1ms) begin transaction
SQL (63.5ms) INSERT INTO "comments" ("commentable_id", "commentable_type", "content",
"created_at", "updated_at") VALUES (?, ?, ?, ?, ?) [["commentable_id", 11],
["commentable_type", "User"], ["content", "Comentário para um usuário"], ["created_at", Tue,
25 Jun 2013 17:39:18 UTC +00:00], ["updated_at", Tue, 25 Jun 2013 17:39:18 UTC +00:
00]]
(405.1ms) commit transaction
=> true

17. Extras
@jlucasps
irb(main):008:0> bill = Bill.first
Bill Load (0.4ms) SELECT "bills".* FROM "bills" ORDER BY bills.date DESC LIMIT 1
=> #<Bill id: 15, name: "123", description: "45", user_id: 9, date: "2013-06-12 00:00:00", value:
#<BigDecimal:43384f8,'0.124E3',9(36)>, created_at: "2013-06-19 01:17:36", updated_at: "2013-
06-19 01:17:36">
irb(main):009:0> comment_2 = Comment.new :content => "Comentário
de uma conta"
=> #<Comment id: nil, content: "Comentário de uma conta", created_at: nil, updated_at: nil,
commentable_id: nil, commentable_type: nil>
irb(main):011:0> comment_2.commentable = bill
=> #<Bill id: 15, name: "123", description: "45", user_id: 9, date: "2013-06-12 00:00:00", value:
#<BigDecimal:41fbae0,'0.124E3',9(36)>, created_at: "2013-06-19 01:17:36", updated_at: "2013-
06-19 01:17:36">
irb(main):012:0> comment_2.save
(0.1ms) begin transaction
SQL (0.7ms) INSERT INTO "comments" ("commentable_id", "commentable_type", "content",
"created_at", "updated_at") VALUES (?, ?, ?, ?, ?) [["commentable_id", 15], ["commentable_type",
"Bill"], ["content", "Comentário de uma conta"], ["created_at", Tue, 25 Jun 2013 17:44:17 UTC
+00:00], ["updated_at", Tue, 25 Jun 2013 17:44:17 UTC +00:00]]
(430.8ms) commit transaction
=> true
irb(main):013:0> bill.comments
Comment Load (0.4ms) SELECT "comments".* FROM "comments" WHERE "comments"."
commentable_id" = 15 AND "comments"."commentable_type" = 'Bill' ORDER BY comments.
created_at DESC
=> [#<Comment id: 3, content: "Comentário de uma conta", created_at: "2013-06-25 17:44:17",
updated_at: "2013-06-25 17:44:17", commentable_id: 15, commentable_type: "Bill">]

18. Extras
@jlucasps
irb(main):014:0> comment.commentable
=> #<User id: 11, name: "teste100@teste.com", email:
"teste100@teste.com", age: nil, created_at: "2013-06-25 01:27:25",
updated_at: "2013-06-25 01:27:25", gender: nil, encrypted_password:
"$2a$10$hMAd4RUymIzxw1JGARKJC.M1hEiAwD0PpwS6uwM9j2RR...",
reset_password_token: nil, reset_password_sent_at: nil,
remember_created_at: nil, sign_in_count: 1, current_sign_in_at: "2013-
06-25 01:27:25", last_sign_in_at: "2013-06-25 01:27:25",
current_sign_in_ip: "127.0.0.1", last_sign_in_ip: "127.0.0.1">
irb(main):015:0> comment_2.commentable
=> #<Bill id: 15, name: "123", description: "45", user_id: 9, date:
"2013-06-12 00:00:00", value: #<BigDecimal:3ed9268,'0.124E3',9(36)
>, created_at: "2013-06-19 01:17:36", updated_at: "2013-06-19 01:17:
36">
irb(main):016:0>

19. Desenvolvimento
Web com Ruby on
Rails
João Lucas Pereira de Santana
gtalk | linkedin | twitter: jlucasps
Obrigado!