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

2. Migration bills
@jlucasps
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rails g
migration CreateBills
invoke active_record
create db/migrate/20130618074102_create_bills.rb
class CreateBills < ActiveRecord::Migration
def change
create_table :bills do |t|
t.column :name, :string, :null => false
t.column :description, :string
t.references :user, :foreign_key => true
t.column :date, :datetime, :null => false
t.column :value, :decimal
t.timestamps
end
end
end
Criar arquivo de migration e executá-lo

3. Migration bills
@jlucasps
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rake db:migrate
== CreateBills: migrating
===============================================
=====
-- create_table(:bills)
-> 0.0073s
-- add_index(:bills, :user_id)
-> 0.0005s
== CreateBills: migrated (0.0080s)
===========================================
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rake db:rollback
== CreateBills: reverting
===============================================
=====
-- remove_index("bills", {:column=>:user_id})
-> 0.0082s
-- drop_table("bills")
-> 0.0003s
== CreateBills: reverted (0.0088s)
===========================================

4. Migration bills
@jlucasps
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rails g migration
AddIndexToBills
invoke active_record
create db/migrate/20130618080649_add_index_to_bills.rb
class AddIndexToBills < ActiveRecord::Migration
def change
add_index :bills, :user_id
end
end
Adicionar índice à foreign_key user_id da tabela bills

5. Migration bills
@jlucasps
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rake db:migrate
== AddIndexToBills: migrating
================================================
-- add_index(:bills, :user_id)
-> 0.0013s
== AddIndexToBills: migrated (0.0015s)
=======================================
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rake db:rollback
== AddIndexToBills: reverting
================================================
-- remove_index("bills", {:column=>:user_id})
-> 0.0306s
== AddIndexToBills: reverted (0.0307s)
=======================================

6. Model Bill
@jlucasps
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
# Scopes
default_scope order("bills.date DESC")
# Públic methods
end

7. Model User
Alterar o model User para conter a associação com Bill
@jlucasps
class User < ActiveRecord::Base
# Attrs accessible
attr_accessible :name, :email, :age, :gender
# Constants
MALE = 1
FEMALE = 2
OTHER = 3
# Validations
validates :name, :presence => true, :allow_blank => false
validates :email, :presence => true, :allow_blank => false
validates_uniqueness_of :email
validates :gender, :presence => true, :if => :adulthood
# Associations
has_many :bills, :dependent => :destroy
# Scopes
# Públic methods
def adulthood
self.age.present? and age >= 18
end
end

8. Rails console
@jlucasps
jlucasps@lotus:/media/truecrypt1/handsonrails/first_app$ rails console
Loading development environment (Rails 3.2.13)
irb(main):001:0> user = User.new(:name => "Joao Lucas", :email =>
"jlucasps@gmail.com")
=> #<User id: nil, name: "Joao Lucas", email: "jlucasps@gmail.com", age: nil,
created_at: nil, updated_at: nil, gender: nil>
irb(main):002:0> user.save
(0.1ms) begin transaction
User Exists (0.2ms) SELECT 1 AS one FROM "users" WHERE "users"."email" = 'jlucasps@gmail.com' LIMIT
1
SQL (24.1ms) INSERT INTO "users" ("age", "created_at", "email", "gender", "name", "updated_at")
VALUES (?, ?, ?, ?, ?, ?) [["age", nil], ["created_at", Tue, 18 Jun 2013 12:52:30 UTC +00:00], ["email",
"jlucasps@gmail.com"], ["gender", nil], ["name", "Joao Lucas"], ["updated_at", Tue, 18 Jun 2013 12:52:
30 UTC +00:00]]
(422.3ms) commit transaction
=> true
irb(main):003:0>
Criar um usuário utilizando o $ rails console

9. Rails console
Criar 2 objetos Bill e associá-los a um usuário.
@jlucasps
irb(main):004:0> bill_1 = Bill.new :name => "Conta 1", :date => Time.
utc(2012, 06, 18), :value => 48.90
=> #<Bill id: nil, name: "Conta 1", description: nil, user_id: nil, date: "2012-06-
18 00:00:00", value: #<BigDecimal:3fc45d8,'0.489E2',18(45)>, created_at: nil,
updated_at: nil>
irb(main):012:0> bill_1.user = user
=> #<User id: 7, name: "Joao Lucas", email: "jlucasps@gmail.com", age: nil,
created_at: "2013-06-18 12:52:30", updated_at: "2013-06-18 12:52:30",
gender: nil>
irb(main):013:0> bill_1.save
(0.1ms) begin transaction
SQL (7.7ms) INSERT INTO "bills" ("created_at", "date", "description", "name", "updated_at", "user_id",
"value") VALUES (?, ?, ?, ?, ?, ?, ?) [["created_at", Tue, 18 Jun 2013 13:03:13 UTC +00:00], ["date", Mon,
18 Jun 2012 00:00:00 UTC +00:00], ["description", nil], ["name", "Conta 1"], ["updated_at", Tue, 18 Jun
2013 13:03:13 UTC +00:00], ["user_id", 7], ["value", #<BigDecimal:31e9878,'0.489E2',18(45)>]]
(413.9ms) commit transaction
=> true

10. Rails console
@jlucasps
irb(main):014:0> bill_2 = Bill.new :name => "Conta 2", :date => Time.
utc(2012, 06, 17), :value => 31.50
=> #<Bill id: nil, name: "Conta 2", description: nil, user_id: nil, date: "2012-06-
17 00:00:00", value: #<BigDecimal:437f150,'0.315E2',18(45)>, created_at: nil,
updated_at: nil>
irb(main):015:0> bill_2.user = user
=> #<User id: 7, name: "Joao Lucas", email: "jlucasps@gmail.com", age: nil,
created_at: "2013-06-18 12:52:30", updated_at: "2013-06-18 12:52:30",
gender: nil>
irb(main):016:0> bill_2.save
(0.1ms) begin transaction
SQL (0.7ms) INSERT INTO "bills" ("created_at", "date", "description", "name", "updated_at", "user_id",
"value") VALUES (?, ?, ?, ?, ?, ?, ?) [["created_at", Tue, 18 Jun 2013 13:05:13 UTC +00:00], ["date", Sun,
17 Jun 2012 00:00:00 UTC +00:00], ["description", nil], ["name", "Conta 2"], ["updated_at", Tue, 18 Jun
2013 13:05:13 UTC +00:00], ["user_id", 7], ["value", #<BigDecimal:3c1e0f0,'0.315E2',18(45)>]]
(427.6ms) commit transaction
=> true

11. Rails console
@jlucasps
irb(main):017:0> Bill.find_all_by_user_id(user.id)
Bill Load (0.3ms) SELECT "bills".* FROM "bills" WHERE "bills"."user_id" = 7
ORDER BY bills.date DESC
=> [#<Bill id: 1, name: "Conta 1", description: nil, user_id: 7, date: "2012-06-18
00:00:00", value: #<BigDecimal:46f1428,'0.489E2',18(45)>, created_at: "2013-
06-18 13:03:13", updated_at: "2013-06-18 13:03:13">, #<Bill id: 2, name:
"Conta 2", description: nil, user_id: 7, date: "2012-06-17 00:00:00", value:
#<BigDecimal:46f8048,'0.315E2',18(45)>, created_at: "2013-06-18 13:05:13",
updated_at: "2013-06-18 13:05:13">]
irb(main):018:0> Bill.find_by_user_id user.id
Bill Load (0.5ms) SELECT "bills".* FROM "bills" WHERE "bills"."user_id" = 7
ORDER BY bills.date DESC LIMIT 1
=> #<Bill id: 1, name: "Conta 1", description: nil, user_id: 7, date: "2012-06-18
00:00:00", value: #<BigDecimal:4706260,'0.489E2',18(45)>, created_at: "2013-
06-18 13:03:13", updated_at: "2013-06-18 13:03:13">
irb(main):019:0>

12. Rails console
@jlucasps
irb(main):020:0> Bill.where(:user_id => user.id).sum(:value)
(0.2ms) SELECT SUM("bills"."value") AS sum_id FROM "bills" WHERE
"bills"."user_id" = 7
=> #<BigDecimal:45230d8,'0.8040000000 000001E2',27(45)>
irb(main):022:0> Bill.where(:user_id => user.id, :date => Time.
utc(2012, 06, 17)).sum(:value)
(0.3ms) SELECT SUM("bills"."value") AS sum_id FROM "bills" WHERE
"bills"."user_id" = 7 AND "bills"."date" = '2012-06-17 00:00:00.000000'
=> #<BigDecimal:4a95c78,'0.315E2',18(45)>
irb(main):029:0> Bill.where(:user_id => user.id).where("bills.
date <= '2012-06-17 00:00:00.000000'").sum(:value)
(0.3ms) SELECT SUM("bills"."value") AS sum_id FROM "bills" WHERE
"bills"."user_id" = 7 AND (bills.date <= '2012-06-17 00:00:00.000000')
=> #<BigDecimal:49b44d0,'0.315E2',18(45)>

13. Scopes
@jlucasps
# Scopes
default_scope order("bills.date DESC")
irb(main):039:0> reload!
irb(main):040:0> user = User.find_by_email("jlucasps@gmail.com")
User Load (0.2ms) SELECT "users".* FROM "users" WHERE "users"."email" =
'jlucasps@gmail.com' LIMIT 1
=> #<User id: 7, name: "Joao Lucas", email: "jlucasps@gmail.com", age: nil,
created_at: "2013-06-18 12:52:30", updated_at: "2013-06-18 12:52:30",
gender: nil>
irb(main):041:0> user.bills
Bill Load (0.2ms) SELECT "bills".* FROM "bills" WHERE "bills"."user_id" = 7
ORDER BY bills.date DESC
=> [#<Bill id: 1, name: "Conta 1", description: nil, user_id: 7, date: "2012-
06-18 00:00:00", value: #<BigDecimal:2d11fd0,'0.489E2',18(45)>,
created_at: "2013-06-18 13:03:13", updated_at: "2013-06-18 13:03:13">,
#<Bill id: 2, name: "Conta 2", description: nil, user_id: 7, date: "2012-06-17
00:00:00", value: #<BigDecimal:3d120b0,'0.315E2',18(45)>, created_at:
"2013-06-18 13:05:13", updated_at: "2013-06-18 13:05:13">]

14. Scopes
@jlucasps
# Scopes
default_scope order("bills.date ASC")
irb(main):044:0> reload!
Reloading...
=> true
irb(main):045:0> user = User.find_by_email("jlucasps@gmail.com")
User Load (0.2ms) SELECT "users".* FROM "users" WHERE "users"."email" =
'jlucasps@gmail.com' LIMIT 1
=> #<User id: 7, name: "Joao Lucas", email: "jlucasps@gmail.com", age: nil, created_at:
"2013-06-18 12:52:30", updated_at: "2013-06-18 12:52:30", gender: nil>
irb(main):046:0> user.bills
Bill Load (0.1ms) SELECT "bills".* FROM "bills" WHERE "bills"."user_id" = 7 ORDER BY
bills.date ASC
=> [#<Bill id: 2, name: "Conta 2", description: nil, user_id: 7, date: "2012-06-17 00:
00:00", value: #<BigDecimal:4971270,'0.315E2',18(45)>, created_at: "2013-06-18 13:
05:13", updated_at: "2013-06-18 13:05:13">, #<Bill id: 1, name: "Conta 1", description:
nil, user_id: 7, date: "2012-06-18 00:00:00", value: #<BigDecimal:4977eb8,'0.489E2',
18(45)>, created_at: "2013-06-18 13:03:13", updated_at: "2013-06-18 13:03:13">]

15. Scopes
@jlucasps
irb(main):051:0> reload!
irb(main):052:0> user = User.find_by_email("jlucasps@gmail.com")
User Load (0.2ms) SELECT "users".* FROM "users" WHERE "users"."email" = 'jlucasps@gmail.com' LIMIT 1
=> #<User id: 7, name: "Joao Lucas", email: "jlucasps@gmail.com", age: nil, created_at: "2013-06-18 12:
52:30", updated_at: "2013-06-18 12:52:30", gender: nil>
irb(main):053:0> user.bills
Bill Load (0.1ms) SELECT "bills".* FROM "bills" WHERE "bills"."user_id" = 7 ORDER BY bills.date DESC
=> [#<Bill id: 1, name: "Conta 1", description: nil, user_id: 7, date: "2012-06-18 00:00:00", value:
#<BigDecimal:49105b0,'0.489E2',18(45)>, created_at: "2013-06-18 13:03:13", updated_at: "2013-06-18
13:03:13">, #<Bill id: 2, name: "Conta 2", description: nil, user_id: 7, date: "2012-06-17 00:00:00", value:
#<BigDecimal:491b050,'0.315E2',18(45)>, created_at: "2013-06-18 13:05:13", updated_at: "2013-06-18
13:05:13">]
irb(main):054:0> user.bills.recents
Bill Load (0.4ms) SELECT "bills".* FROM "bills" WHERE "bills"."user_id" = 7 ORDER BY bills.date DESC
LIMIT 5
=> [#<Bill id: 1, name: "Conta 1", description: nil, user_id: 7, date: "2012-06-18 00:00:00", value:
#<BigDecimal:4938560,'0.489E2',18(45)>, created_at: "2013-06-18 13:03:13", updated_at: "2013-06-18
13:03:13">, #<Bill id: 2, name: "Conta 2", description: nil, user_id: 7, date: "2012-06-17 00:00:00", value:
#<BigDecimal:49368f0,'0.315E2',18(45)>, created_at: "2013-06-18 13:05:13", updated_at: "2013-06-18
13:05:13">]
# Scopes
default_scope order("bills.date DESC")
scope :recents, order("bills.date DESC").limit(5)

16. Scopes
@jlucasps
irb(main):058:0> reload!
irb(main):059:0> user = User.find_by_email("jlucasps@gmail.com")
User Load (0.2ms) SELECT "users".* FROM "users" WHERE "users"."email" =
'jlucasps@gmail.com' LIMIT 1
=> #<User id: 7, name: "Joao Lucas", email: "jlucasps@gmail.com", age: nil,
created_at: "2013-06-18 12:52:30", updated_at: "2013-06-18 12:52:30", gender:
nil>
irb(main):060:0> user.bills.recents_by_date Time.utc(2012, 06, 17)
Bill Load (0.3ms) SELECT "bills".* FROM "bills" WHERE "bills"."user_id" = 7 AND
(bills.date <= '2012-06-17 00:00:00.000000') ORDER BY bills.date DESC LIMIT 5
=> [#<Bill id: 2, name: "Conta 2", description: nil, user_id: 7, date: "2012-06-17
00:00:00", value: #<BigDecimal:4b07e90,'0.315E2',18(45)>, created_at: "2013-
06-18 13:05:13", updated_at: "2013-06-18 13:05:13">]
scope :recents, order("bills.date DESC").limit(5)
scope :recents_by_date, lambda {|date|
where("bills.date <= '#{date.strftime('%Y-%m-%d %H:%M:%S.000000')}'").order
("bills.date DESC").limit(5)
}

17. Commit
$ git add .
$ git commit -m "Criação de scopes"
Agora vamos adicionar relacionamentos entre
as rotas de Usuários e Contas
@jlucasps
...
resources :users do
resources :bills
end
...

18. Bills
@jlucasps
Alterar view de show do modelo user: /app/views/users/show.html.erb
<p id="notice"><%= notice %></p>
<p><b>Nome:</b><%= @user.name %></p>
<p><b>email:</b><%= @user.email %></p>
<p><b>Idade:</b><%= @user.age %></p>
<p><b>Sexo:</b><%= @user.gender %></p>
<div id='new_bill'>
<%= render :partial => 'bills/new', :locals => {:bill => Bill.new, :user => @user} %>
</div>
<div id='bills'>
<%= render :partial => 'bills/index', :locals => {:bills => @user.bills} %>
</div>
<%= link_to 'Edit', edit_user_path(@user), :class => "btn" %> |
<%= link_to 'Back', users_path, :class => "btn" %>

19. Bills
@jlucasps
Criar partial para lista contas: /app/views/bills/_index.html.erb
<% if bills.any? %>
<% bills.each do |bill| %>
<div class='well well-small'>
<h4><%= bill.name %></h4>
<%= bill.description %>
<h5><%= l(bill.date, :forma => :long) %></h5>
<h3><%= bill.value.round(2) %></h3>
</div>
<% end %>
<% else %>
<div class='alert'>
<%= t('no_bill_registered_to_this_user') %>
</div>
<% end %>

20. Bills
@jlucasps
Criar partial com formulário de nova conta: /app/views/bills/_new.html.erb
<hr>
<h4><%= t('new_bill') %></h4>
<%= form_for([user, bill], :remote => true) do |f| %>
<%= render :partial => 'shared/error_messages' , :locals => {:resource => bill} %
>
<%= f.hidden_field :user_id, :value => user.id %>
<%= f.label :name %>
<%= f.text_field :name %>
<%= f.label :description %>
<%= f.text_field :description %>
<%= f.label :date %>
<%= f.text_field :date %>
<%= f.label :value %>
<%= f.text_field :value %>
<% end %>

21. Bills
@jlucasps
Criar controller bills e action create
class BillsController < ApplicationController
def create
@bill = Bill.new(params[:bill])
flash[:notice] = (@bill.save ? t('saved_successfully') : t('error_while_saving'))
end
end

22. Bills
@jlucasps
Criar view create /app/views/bills/create.js.erb
<% if @bill.persisted? %>
$("#bills").html("<%= j(render :partial => 'bills/index', :locals => {:
bills => @bill.user.bills}) %>");
$("#bills").prepend("<%= j notice %>");
$("#new_bill").html("<%= j(render :partial => 'bills/new', :locals =>
{:bill => Bill.new, :user => @bill.user} ) %>");
<% else %>
$("#new_bill").html("<%= j(render :partial => 'bills/new', :locals =>
{:bill => @bill, :user => @bill.user}) %>");
<% end %>

23. Bills
@jlucasps
Alterar view de index para apresentar link para edit e destroy
<hr>
<h4><%= t('bills') %></h4>
<% if bills.any? %>
<% bills.each do |bill| %>
<div id='bill_<%= bill.id %>' class='well well-small'>
<h4><%= bill.name %></h4>
<%= bill.description %>
<h5><%= l(bill.date, :forma => :long) %></h5>
<h3><%= bill.value.round(2) %></h3>
<%= link_to t('edit'), edit_user_bill_path(bill.user, bill), :class => "btn btn-
primary", :remote => true %>
<%= link_to t('delete'), [bill.user, bill], :remote => true, :method => :delete, :
class => "btn btn-danger" %>
</div>
<% end %>
<% else %>
<div class='alert'>
<%= t('no_bill_registered_to_this_user') %>
</div>
<% end %>

24. Bills
@jlucasps
Criar action e view destroy
def destroy
@bill = Bill.find(params[:id])
@bill.destroy
end
<% if @bill.destroyed? %>
$("#bill_<%= @bill.id %>").remove();
<% else %>
$("#bill_<%= @bill.id %>").prepend("<%= t
('error_while_deleting') %>");
<% end %>

25. Bills
@jlucasps
Criar action e view edit
def edit
@bill = Bill.find(params[:id])
end
$("#new_bill").html("<%= j(render :partial => 'bills/new', :
locals => {:bill => @bill, :user => @bill.user}) %>");
$('html, body').animate({scrollTop: $("#new_bill").offset().
top});

26. Bills
@jlucasps
Implementar action e view de update
def update
@bill = Bill.find(params[:id])
flash[:notice] = (@bill.update_attributes(params[:bill]) ? t
('updated_successfully') : t('error_while_updating'))
end
<% if @bill.valid? %>
$("#bills").html("<%= j(render :partial => 'bills/index', :locals => {:bills =>
@bill.user.bills}) %>");
$("#bills").prepend("<%= j notice %>");
$("#new_bill").html("<%= j(render :partial => 'bills/new', :locals => {:bill
=> Bill.new, :user => @bill.user} ) %>");
<% else %>
$("#new_bill").html("<%= j(render :partial => 'bills/new', :locals => {:bill
=> @bill, :user => @bill.user}) %>");
<% end %>

27. Bills
@jlucasps

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