10 Things You Didn't Know Rails Could do

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234 slides

10 Things You Didn’t Know Rails Could Do
James Edward Gray II I am a regular on the
Ruby Rogues podcast I have been a Rubyist for eight years now I have written a lot of documentation and code for Ruby, including CSV
10 Things You Didn’t Know Rails Could Do
10 Things You Didn’t Know Rails Could Do 4.2⨉ more
awesome! 42
Rails 3.2.3 Can…
Get You a Hug, Every Friday 1 http://hugfriday.com/
Interfaces Ways to give Rails a hug
Run From a Single File From Avdi Grimm 2
Remind You of Things 3 class UsersController < ApplicationController #
TODO: Make it possible to create new users. end
Remind You of Things 3 class UsersController < ApplicationController #
TODO: Make it possible to create new users. end class User < ActiveRecord::Base # FIXME: Should token really be accessible? attr_accessible :bio, :email, :name, :token end
<%# OPTIMIZE: Paginate this listing. %> <%= render Article.all %>
Remind You of Things 3 class UsersController < ApplicationController # TODO: Make it possible to create new users. end class User < ActiveRecord::Base # FIXME: Should token really be accessible? attr_accessible :bio, :email, :name, :token end
$ rake notes app/controllers/users_controller.rb: * [ 2] [TODO] Make it
possible to create new users. app/models/user.rb: * [ 2] [FIXME] Should token really be accessible? app/views/articles/index.html.erb: * [ 1] [OPTIMIZE] Paginate this listing. <%# OPTIMIZE: Paginate this listing. %> <%= render Article.all %> Remind You of Things 3 class UsersController < ApplicationController # TODO: Make it possible to create new users. end class User < ActiveRecord::Base # FIXME: Should token really be accessible? attr_accessible :bio, :email, :name, :token end
$ rake notes app/controllers/users_controller.rb: * [ 2] [TODO] Make it
possible to create new users. app/models/user.rb: * [ 2] [FIXME] Should token really be accessible? app/views/articles/index.html.erb: * [ 1] [OPTIMIZE] Paginate this listing. <%# OPTIMIZE: Paginate this listing. %> <%= render Article.all %> Remind You of Things 3 class UsersController < ApplicationController # TODO: Make it possible to create new users. end class User < ActiveRecord::Base # FIXME: Should token really be accessible? attr_accessible :bio, :email, :name, :token end
Remind You of Things 3 class UsersController < ApplicationController # TODO: Make it possible to create new users. end class User < ActiveRecord::Base # FIXME: Should token really be accessible? attr_accessible :bio, :email, :name, :token end $ rake notes:todo app/controllers/users_controller.rb: * [ 2] Make it possible to create new users. $ rake notes:fixme app/models/user.rb: * [ 2] Should token really be accessible?
Remind You of Things 3 class UsersController < ApplicationController # TODO: Make it possible to create new users. end class User < ActiveRecord::Base # FIXME: Should token really be accessible? attr_accessible :bio, :email, :name, :token end $ rake notes:todo app/controllers/users_controller.rb: * [ 2] Make it possible to create new users. $ rake notes:fixme app/models/user.rb: * [ 2] Should token really be accessible?
Remind You of Things 3 class Article < ActiveRecord::Base belongs_to
:user attr_accessible :body, :subject # JEG2: Add that code from your blog here. end $ rake notes:custom ANNOTATION=JEG2 app/models/article.rb: * [ 4] Add that Code from your blog here.
Remind You of Things 3 class Article < ActiveRecord::Base belongs_to
:user attr_accessible :body, :subject # JEG2: Add that code from your blog here. end $ rake notes:custom ANNOTATION=JEG2 app/models/article.rb: * [ 4] Add that Code from your blog here.
Remind You of Things 3
Sandbox Your Console 4 $ rails r 'p [Article, Comment,
User].map(&:count)' [0, 0, 0] $ rails c --sandbox Loading development environment in sandbox (Rails 3.2.3) Any modifications you make will be rolled back on exit >> jeg2 = User.create!(name: "James Edward Gray II") => #<User id: 1, name: "James Edward Gray II", …> >> article = Article.new(subject: "First Post").tap { |a| a.user = jeg2; a.save! } => #<Article id: 1, user_id: 1, subject: "First Post", …> >> Comment.new(body: "I need to add this.").tap { |c| c.user, c.article = jeg2, article; c.save! } => #<Comment id: 1, user_id: 1, article_id: 1, body: "I need to add this.", …> >> [Article, Comment, User].map(&:count) => [1, 1, 1] >> exit $ rails r 'p [Article, Comment, User].map(&:count)' [0, 0, 0]
Run Helper Methods in the Console 5 $ rails c
Loading development environment (Rails 3.2.3) >> helper.number_to_currency(100) => "$100.00" >> helper.time_ago_in_words(3.days.ago) => "3 days"
Run Helper Methods in the Console 5 $ rails c
Loading development environment (Rails 3.2.3) >> helper.number_to_currency(100) => "$100.00" >> helper.time_ago_in_words(3.days.ago) => "3 days"
Use Non-WEBrick Servers in Development 6 source 'https://rubygems.org' # ...
group :development do gem "thin" end $ rails s thin => Booting Thin => Rails 3.2.3 application starting in development on http://0.0.0.0:3000 => Call with -d to detach => Ctrl-C to shutdown server >> Thin web server (v1.3.1 codename Triple Espresso) >> Maximum connections set to 1024 >> Listening on 0.0.0.0:3000, CTRL+C to stop
Use Non-WEBrick Servers in Development 6 source 'https://rubygems.org' # ...
group :development do gem "thin" end $ rails s thin => Booting Thin => Rails 3.2.3 application starting in development on http://0.0.0.0:3000 => Call with -d to detach => Ctrl-C to shutdown server >> Thin web server (v1.3.1 codename Triple Espresso) >> Maximum connections set to 1024 >> Listening on 0.0.0.0:3000, CTRL+C to stop
Allow You to Tap Into its Conﬁguration From Josh Susser
7 # lib/custom/railtie.rb module Custom class Railtie < Rails::Railtie config.custom = ActiveSupport::OrderedOptions.new end end
7 # lib/custom/railtie.rb module Custom class Railtie < Rails::Railtie config.custom = ActiveSupport::OrderedOptions.new end end
7 # lib/custom/railtie.rb module Custom class Railtie < Rails::Railtie config.custom = ActiveSupport::OrderedOptions.new end end # config/application.rb # ... require_relative "../lib/custom/railtie" module Blog class Application < Rails::Application # ... config.custom.setting = 42 end end
Keep You Entertained 8
Keep You Entertained 8
The Database A place to store all that drama
Understand Shorthand Migrations $ rails g resource user name:string email:string
token:string bio:text 9 From José Valim
token:string bio:text $ rails g resource user name email token:string{6} bio:text 9 From José Valim
token:string bio:text $ rails g resource user name email token:string{6} bio:text class CreateUsers < ActiveRecord::Migration def change create_table :users do |t| t.string :name t.string :email t.string :token, :limit => 6 t.text :bio t.timestamps end end end 9 From José Valim
Add Indexes to Migrations $ rails g resource user name:index
email:uniq token:string{6} bio:text 10 From José Valim
email:uniq token:string{6} bio:text class CreateUsers < ActiveRecord::Migration def change create_table :users do |t| t.string :name t.string :email t.string :token, :limit => 6 t.text :bio t.timestamps end add_index :users, :name add_index :users, :email, :unique => true end end 10 From José Valim
Add Associations to a Migration $ rails g resource article
user:references subject body:text 11 From José Valim
user:references subject body:text class CreateArticles < ActiveRecord::Migration def change create_table :articles do |t| t.references :user t.string :subject t.text :body t.timestamps end add_index :articles, :user_id end end class Article < ActiveRecord::Base belongs_to :user attr_accessible :body, :subject end 11 From José Valim
user:references subject body:text class CreateArticles < ActiveRecord::Migration def change create_table :articles do |t| t.references :user t.string :subject t.text :body t.timestamps end add_index :articles, :user_id end end class Article < ActiveRecord::Base belongs_to :user attr_accessible :body, :subject end $ rails g resource comment user:belongs_to article:belongs_to body:text 11 From José Valim
user:references subject body:text class CreateArticles < ActiveRecord::Migration def change create_table :articles do |t| t.references :user t.string :subject t.text :body t.timestamps end add_index :articles, :user_id end end class Article < ActiveRecord::Base belongs_to :user attr_accessible :body, :subject end $ rails g resource comment user:belongs_to article:belongs_to body:text 11 From José Valim
Show You the Status of the Database $ rake db:migrate:status
database: db/development.sqlite3 Status Migration ID Migration Name -------------------------------------------------- up 20120414155612 Create users up 20120414160528 Create articles down 20120414161355 Create comments 12
Show You the Status of the Database $ rake db:migrate:status
database: db/development.sqlite3 Status Migration ID Migration Name -------------------------------------------------- up 20120414155612 Create users up 20120414160528 Create articles down 20120414161355 Create comments 12
Import Your CSV Data 13 Name,Email James,[email protected] Dana,[email protected] Summer,[email protected] require
"csv" namespace :users do desc "Import users from a CSV file" task :import => :environment do path = ENV.fetch("CSV_FILE") { File.join(File.dirname(__FILE__), *%w[.. .. db data users.csv]) } CSV.foreach(path, headers: true, header_converters: :symbol) do |row| User.create(row.to_hash) end end end
Store CSV in Your Database 14 class Article < ActiveRecord::Base
require "csv" module CSVSerializer module_function def load(field) field.to_s.parse_csv end def dump(object) Array(object).to_csv end end serialize :categories, CSVSerializer # ... attr_accessible :body, :subject, :categories end
require "csv" module CSVSerializer module_function def load(field) field.to_s.parse_csv end def dump(object) Array(object).to_csv end end serialize :categories, CSVSerializer # ... attr_accessible :body, :subject, :categories end
require "csv" module CSVSerializer module_function def load(field) field.to_s.parse_csv end def dump(object) Array(object).to_csv end end serialize :categories, CSVSerializer # ... attr_accessible :body, :subject, :categories end $ rails c Loading development environment (Rails 3.2.3) >> Article.create!(subject: "JEG2's Rails Hacks", categories: ["Rails", "Gray, James", "hacks"]) => #<Article id: 1, …> >> Article.last.categories => ["Rails", "Gray, James", "hacks"] >> exit $ sqlite3 db/development.sqlite3 'SELECT categories FROM articles ORDER BY created_at DESC LIMIT 1' -- Loading resources from /Users/james/.sqliterc categories -------------------------- Rails,"Gray, James",hacks
“Pluck” Fields Out of Your Database 15 From Ryan Bates
$ rails c Loading development environment (Rails 3.2.3) >> User.select(:email).map(&:email) User Load (0.1ms) SELECT email FROM "users" => ["[email protected]", "[email protected]", "[email protected]"] >> User.pluck(:email) (0.2ms) SELECT email FROM "users" => ["[email protected]", "[email protected]", "[email protected]"] >> User.uniq.pluck(:email) (0.2ms) SELECT DISTINCT email FROM "users" => ["[email protected]", "[email protected]", "[email protected]"]
Count Records in Groups 16 $ rails g resource event
article:belongs_to trigger
article:belongs_to trigger $ rails c Loading development environment (Rails 3.2.3) >> article = Article.last => #<Article id: 1, …> >> {edit: 3, view: 10}.each do |trigger, count| ?> count.times do ?> Event.new(trigger: trigger).tap { |e| e.article = article; e.save! } >> end >> end => {:edit=>3, :view=>10} >> Event.count => 13 >> Event.group(:trigger).count => {"edit"=>3, "view"=>10}
Allow You to Override Associations 17 From Josh Susser class
Car < ActiveRecord::Base belongs_to :owner belongs_to :previous_owner, class_name: "Owner" def owner=(new_owner) self.previous_owner = owner super end end
Allow You to Override Associations 17 From Josh Susser class
Car < ActiveRecord::Base belongs_to :owner belongs_to :previous_owner, class_name: "Owner" def owner=(new_owner) self.previous_owner = owner super end end
Instantiate Records Without a Database 18 $ rails c Loading
development environment (Rails 3.2.3) >> User.find(1) => #<User id: 1, name: "James", email: "[email protected]", …> >> jeg2 = User.instantiate("id" => 1, "email" => "[email protected]") => #<User id: 1, email: "[email protected]"> >> jeg2.name = "James Edward Gray II" => "James Edward Gray II" >> jeg2.save! => true >> User.find(1) => #<User id: 1, name: "James Edward Gray II", email: "[email protected]", …>
Use Limitless Strings in PostgreSQL 19 From Josh Susser $
rails g resource user bio # ... module PsqlApp class Application < Rails::Application # ... # Switch to limitless strings initializer "postgresql.no_default_string_limit" do ActiveSupport.on_load(:active_record) do adapter = ActiveRecord::ConnectionAdapters::PostgreSQLAdapter adapter::NATIVE_DATABASE_TYPES[:string].delete(:limit) end end end end
rails g resource user bio $ rails c Loading development environment (Rails 3.2.3) >> very_long_bio = "X" * 10_000; :set => :set >> User.create!(bio: very_long_bio) => #<User id: 1, bio: "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XX...", created_at: "2012-04-14 23:02:08", updated_at: "2012-04-14 23:02:08"> >> User.last.bio.size => 10000
rails g resource user bio $ rails c Loading development environment (Rails 3.2.3) >> very_long_bio = "X" * 10_000; :set => :set >> User.create!(bio: very_long_bio) => #<User id: 1, bio: "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XX...", created_at: "2012-04-14 23:02:08", updated_at: "2012-04-14 23:02:08"> >> User.last.bio.size => 10000
Use Full Text Search in PostgreSQL 20 $ rails g
resource article subject body:text From PeepCode
Use Full Text Search in PostgreSQL 20 class CreateArticles <
ActiveRecord::Migration def change create_table :articles do |t| t.string :subject t.text :body t.column :search, "tsvector" t.timestamps end execute <<-END_SQL CREATE INDEX articles_search_index ON articles USING gin(search); CREATE TRIGGER articles_search_update BEFORE INSERT OR UPDATE ON articles FOR EACH ROW EXECUTE PROCEDURE tsvector_update_trigger( search, 'pg_catalog.english', subject, body ); END_SQL end end From PeepCode
Use Full Text Search in PostgreSQL 20 From PeepCode class
Article < ActiveRecord::Base attr_accessible :body, :subject def self.search(query) sql = sanitize_sql_array(["plainto_tsquery('english', ?)", query]) where( "search @@ #{sql}" ).order( "ts_rank_cd(search, #{sql}) DESC" ) end end
Use Full Text Search in PostgreSQL 20 From PeepCode class
Article < ActiveRecord::Base attr_accessible :body, :subject def self.search(query) sql = sanitize_sql_array(["plainto_tsquery('english', ?)", query]) where( "search @@ #{sql}" ).order( "ts_rank_cd(search, #{sql}) DESC" ) end end
Use Full Text Search in PostgreSQL 20 From PeepCode $
rails c Loading development environment (Rails 3.2.3) >> Article.create!(subject: "Full Text Search") => #<Article id: 1, …> >> Article.create!(body: "A stemmed search.") => #<Article id: 2, …> >> Article.create!(body: "You won't find me!") => #<Article id: 3, …> >> Article.search("search").map { |a| a.subject || a.body } => ["Full Text Search", "A stemmed search."] >> Article.search("stemming").map { |a| a.subject || a.body } => ["A stemmed search."]
Use Different a Database for Each User 21 def connect_to_user_database(name)
config = ActiveRecord::Base.configurations["development"] .merge("database" => "db/#{name}.sqlite3") ActiveRecord::Base.establish_connection(config) end
config = ActiveRecord::Base.configurations["development"] .merge("database" => "db/#{name}.sqlite3") ActiveRecord::Base.establish_connection(config) end require "user_database"
Use Different a Database for Each User 21 namespace :db
do desc "Add a new user database" task :add => %w[environment load_config] do name = ENV.fetch("DB_NAME") { fail "DB_NAME is required" } connect_to_user_database(name) ActiveRecord::Base.connection end namespace :migrate do desc "Migrate all user databases" task :all => %w[environment load_config] do ActiveRecord::Migration.verbose = ENV.fetch("VERBOSE", "true") == "true" Dir.glob("db/*.sqlite3") do |file| next if file == "db/test.sqlite3" connect_to_user_database(File.basename(file, ".sqlite3")) ActiveRecord::Migrator.migrate( ActiveRecord::Migrator.migrations_paths, ENV["VERSION"] && ENV["VERSION"].to_i ) do |migration| ENV["SCOPE"].blank? || (ENV["SCOPE"] == migration.scope) end end end end end
Use Different a Database for Each User 21 namespace :db
do desc "Add a new user database" task :add => %w[environment load_config] do name = ENV.fetch("DB_NAME") { fail "DB_NAME is required" } connect_to_user_database(name) ActiveRecord::Base.connection end namespace :migrate do desc "Migrate all user databases" task :all => %w[environment load_config] do ActiveRecord::Migration.verbose = ENV.fetch("VERBOSE", "true") == "true" Dir.glob("db/*.sqlite3") do |file| next if file == "db/test.sqlite3" connect_to_user_database(File.basename(file, ".sqlite3")) ActiveRecord::Migrator.migrate( ActiveRecord::Migrator.migrations_paths, ENV["VERSION"] && ENV["VERSION"].to_i ) do |migration| ENV["SCOPE"].blank? || (ENV["SCOPE"] == migration.scope) end end end end end
Use Different a Database for Each User 21 $ rails
g resource user name $ rake db:add DB_NAME=ruby_rogues $ rake db:add DB_NAME=grays $ rake db:migrate:all == CreateUsers: migrating ================================== -- create_table(:users) -> 0.0008s == CreateUsers: migrated (0.0008s) ========================= == CreateUsers: migrating ================================== -- create_table(:users) -> 0.0007s == CreateUsers: migrated (0.0008s) =========================
c >> connect_to_user_database("ruby_rogues") => #<ActiveRecord::ConnectionAdapters::ConnectionPool…> >> User.create!(name: "Chuck") => #<User id: 1, name: "Chuck", …> >> User.create!(name: "Josh") => #<User id: 2, name: "Josh", …> >> User.create!(name: "Avdi") => #<User id: 3, name: "Avdi", …> … >> connect_to_user_database("grays") => #<ActiveRecord::ConnectionAdapters::ConnectionPool…> >> User.create!(name: "James") => #<User id: 1, name: "James", …> >> User.create!(name: "Dana") => #<User id: 2, name: "Dana", …> >> User.create!(name: "Summer") => #<User id: 3, name: "Summer", …>
Use Different a Database for Each User 21 class ApplicationController
< ActionController::Base protect_from_forgery before_filter :connect_to_database private def connect_to_database connect_to_user_database(request.subdomains.first) end end
Use Different a Database for Each User 21 class ApplicationController
< ActionController::Base protect_from_forgery before_filter :connect_to_database private def connect_to_database connect_to_user_database(request.subdomains.first) end end
Use Different a Database for Each User 21
Use Different a Database for Each User 21
Intermission Am I going to make it???
Why Do This? I’m trying to give you new ideas
Studies show this will help you solve Rails problems Also, it’s fun! Remember to have fun
Less Talk, More Tricks!!!
Reﬁne Your Fashion Sense http://www.ﬂickr.com/photos/oreillyconf/5735037920/ 22
Refine Your Fashion Sense http://www.flickr.com/photos/oreillyconf/5735037920/ http://www.flickr.com/photos/oreillyconf/5735038376/ 22
Refine Your Fashion Sense http://www.flickr.com/photos/oreillyconf/5735037920/ http://www.flickr.com/photos/oreillyconf/5735038376/ http://www.flickr.com/photos/aaronp/4609780419/ 22
Ruby Extensions Updating Ruby’s fashion sense
Write Files Atomically 23 class Comment < ActiveRecord::Base # ...
Q_DIR = (Rails.root + "comment_queue").tap(&:mkpath) after_save :queue_comment def queue_comment File.atomic_write(Q_DIR + "#{id}.txt") do |f| f.puts "Article: #{article.subject}" f.puts "User: #{user.name}" f.puts body end end end
Write Files Atomically 23 class Comment < ActiveRecord::Base # ...
Q_DIR = (Rails.root + "comment_queue").tap(&:mkpath) after_save :queue_comment def queue_comment File.atomic_write(Q_DIR + "#{id}.txt") do |f| f.puts "Article: #{article.subject}" f.puts "User: #{user.name}" f.puts body end end end
Write Files Atomically 23 $ ls comment_queue ls: comment_queue: No
such file or directory $ rails r 'Comment.new(body: "Queue me.").tap { |c| c.article, c.user = Article.first, User.first; c.save! }' $ ls comment_queue 1.txt $ cat comment_queue/1.txt Article: JEG2's Rails Hacks User: James Edward Gray II Queue me.
Write Files Atomically 23 $ ls comment_queue ls: comment_queue: No
such file or directory $ rails r 'Comment.new(body: "Queue me.").tap { |c| c.article, c.user = Article.first, User.first; c.save! }' $ ls comment_queue 1.txt $ cat comment_queue/1.txt Article: JEG2's Rails Hacks User: James Edward Gray II Queue me.
Merge Nested Hashes 24 $ rails c Loading development environment
(Rails 3.2.3) >> {nested: {one: 1}}.merge(nested: {two: 2}) => {:nested=>{:two=>2}} >> {nested: {one: 1}}.deep_merge(nested: {two: 2}) => {:nested=>{:one=>1, :two=>2}}
Merge Nested Hashes 24 $ rails c Loading development environment
(Rails 3.2.3) >> {nested: {one: 1}}.merge(nested: {two: 2}) => {:nested=>{:two=>2}} >> {nested: {one: 1}}.deep_merge(nested: {two: 2}) => {:nested=>{:one=>1, :two=>2}}
Remove Speciﬁc Keys From a Hash 25 $ rails c
Loading development environment (Rails 3.2.3) >> params = {controller: "home", action: "index", from: "Google"} => {:controller=>"home", :action=>"index", :from=>"Google"} >> params.except(:controller, :action) => {:from=>"Google"}
Remove Speciﬁc Keys From a Hash 25 $ rails c
Loading development environment (Rails 3.2.3) >> params = {controller: "home", action: "index", from: "Google"} => {:controller=>"home", :action=>"index", :from=>"Google"} >> params.except(:controller, :action) => {:from=>"Google"}
Add Defaults to Hash 26 $ rails c Loading development
environment (Rails 3.2.3) >> {required: true}.merge(optional: true) => {:required=>true, :optional=>true} >> {required: true}.reverse_merge(optional: true) => {:optional=>true, :required=>true} >> {required: true, optional: false}.merge(optional: true) => {:required=>true, :optional=>true} >> {required: true, optional: false}.reverse_merge(optional: true) => {:optional=>false, :required=>true}
Answer Questions About Strings 27 $ rails g migration add_status_to_articles
status
status class AddStatusToArticles < ActiveRecord::Migration def change add_column :articles, :status, :string, default: "Draft", null: false end end
status class AddStatusToArticles < ActiveRecord::Migration def change add_column :articles, :status, :string, default: "Draft", null: false end end
Answer Questions About Strings 27 $ rails c Loading development
environment (Rails 3.2.3) >> env = Rails.env => "development" >> env.development? => true >> env.test? => false >> "magic".inquiry.magic? => true >> article = Article.first => #<Article id: 1, …, status: "Draft"> >> article.draft? => true >> article.published? => false
Answer Questions About Strings 27 class Article < ActiveRecord::Base #
... STATUSES = %w[Draft Published] validates_inclusion_of :status, in: STATUSES def method_missing(method, *args, &block) if method =~ /\A#{STATUSES.map(&:downcase).join("|")}\?\z/ status.downcase.inquiry.send(method) else super end end end
Get you on the cover of a magazine The hairdo
may be required http://www.rubyinside.com/rubys-popularity-scales-new-heights-19.html 28
Get you voted “Hottest Hacker” http://pageman.multiply.com/links/item/21/David_Heinemeier_Hanssons_Blog 29
Get you voted “Hottest Hacker” http://pageman.multiply.com/links/item/21/David_Heinemeier_Hanssons_Blog 29
Get you voted “Hottest Hacker” http://pageman.multiply.com/links/item/21/David_Heinemeier_Hanssons_Blog http://torrentfreak.com/richard-stallman-opts-to-disobey-anti-piracy-law-110610/ 29
Views It’s all about how we look
Hide Comments From Your Users 30  <%# ERb comments do not %> <h1>Home Page</h1> From The Rails View
in the rendered content --> <%# ERb comments do not %> <h1>Home Page</h1> From The Rails View
in the rendered content --> <%# ERb comments do not %> <h1>Home Page</h1> <body>  <h1>Home Page</h1> </body> From The Rails View
Understand a Shorter ERb Syntax 31 # ... module Blog
class Application < Rails::Application # ... # Broken: config.action_view.erb_trim_mode = '%' ActionView::Template::Handlers::ERB.erb_implementation = Class.new(ActionView::Template::Handlers::Erubis) do include ::Erubis::PercentLineEnhancer end end end % if current_user.try(:admin?) <%= render "edit_links" %> % end
Use Blocks to Avoid Assignments in Views 32 <table> <%
@cart.products.each do |product| %> <tr> <td><%= product.name %></td> <td><%= number_to_currency product.price %></td> </tr> <% end %> <tr> <td>Subtotal</td> <td><%= number_to_currency @cart.total %></td> </tr> <tr> <td>Tax</td> <td><%= number_to_currency(tax = calculate_tax(@cart.total)) %></td> </tr> <tr> <td>Total</td> <td><%= number_to_currency(@cart.total + tax) %></td> </tr> </table> From The Rails View
<table> <% @cart.products.each do |product| %> <tr> <td><%= product.name %></td>
<td><%= number_to_currency product.price %></td> </tr> <% end %> <tr> <td>Subtotal</td> <td><%= number_to_currency @cart.total %></td> </tr> <% calculate_tax @cart.total do |tax| %> <tr> <td>Tax</td> <td><%= number_to_currency tax %></td> </tr> <tr> <td>Total</td> <td><%= number_to_currency(@cart.total + tax) %></td> </tr> <% end %> </table> Use Blocks to Avoid Assignments in Views 32 From The Rails View
<table> <% @cart.products.each do |product| %> <tr> <td><%= product.name %></td>
<td><%= number_to_currency product.price %></td> </tr> <% end %> <tr> <td>Subtotal</td> <td><%= number_to_currency @cart.total %></td> </tr> <% calculate_tax @cart.total do |tax| %> <tr> <td>Tax</td> <td><%= number_to_currency tax %></td> </tr> <tr> <td>Total</td> <td><%= number_to_currency(@cart.total + tax) %></td> </tr> <% end %> </table> Use Blocks to Avoid Assignments in Views 32 From The Rails View
Use Blocks to Avoid Assignments in Views 32 module CartHelper
def calculate_tax(total, user = current_user) tax = TaxTable.for(user).calculate(total) if block_given? yield tax else tax end end end From The Rails View
Use Blocks to Avoid Assignments in Views 32 module CartHelper
def calculate_tax(total, user = current_user) tax = TaxTable.for(user).calculate(total) if block_given? yield tax else tax end end end From The Rails View
Generate Multiple Tags at Once 33 From José Valim <h1>Articles</h1>
<% @articles.each do |article| %> <%= content_tag_for(:div, article) do %> <h2><%= article.subject %></h2> <% end %> <% end %>
<% @articles.each do |article| %> <%= content_tag_for(:div, article) do %> <h2><%= article.subject %></h2> <% end %> <% end %>
<% @articles.each do |article| %> <%= content_tag_for(:div, article) do %> <h2><%= article.subject %></h2> <% end %> <% end %> <h1>Articles</h1> <%= content_tag_for(:div, @articles) do |article| %> <h2><%= article.subject %></h2> <% end %>
<% @articles.each do |article| %> <%= content_tag_for(:div, article) do %> <h2><%= article.subject %></h2> <% end %> <% end %> <h1>Articles</h1> <%= content_tag_for(:div, @articles) do |article| %> <h2><%= article.subject %></h2> <% end %>
Render Any Object 34 From José Valim class Event <
ActiveRecord::Base # ... def to_partial_path "events/#{trigger}" # events/edit or events/view end end
ActiveRecord::Base # ... def to_partial_path "events/#{trigger}" # events/edit or events/view end end <%= render partial: @events, as: :event %>
Group Menu Entries 35 From The Rails View
Group Menu Entries 35 From The Rails View <%= select_tag(
:grouped_menu, grouped_options_for_select( "Group A" => %w[One Two Three], "Group B" => %w[One Two Three] ) ) %>
Group Menu Entries 35 From The Rails View <%= select_tag(
:grouped_menu, grouped_options_for_select( "Group A" => %w[One Two Three], "Group B" => %w[One Two Three] ) ) %>
Build Forms the Way You Like Them 36 From The
Rails View class LabeledFieldsWithErrors < ActionView::Helpers::FormBuilder def errors_for(attribute) if (errors = object.errors[attribute]).any? @template.content_tag(:span, errors.to_sentence, class: "error") end end def method_missing(method, *args, &block) if %r{ \A (?<labeled>labeled_)? (?<wrapped>\w+?) (?<with_errors>_with_errors)? \z }x =~ method and respond_to?(wrapped) and [labeled, with_errors].any?(&:present?) attribute, tags = args.first, [ ] tags << label(attribute) if labeled.present? tags << send(wrapped, *args, &block) tags << errors_for(attribute) if with_errors.present? tags.join(" ").html_safe else super end end end
Rails View # ... module Blog class Application < Rails::Application # ... require "labeled_fields_with_errors" config.action_view.default_form_builder = LabeledFieldsWithErrors config.action_view.field_error_proc = ->(field, _) { field } end end
Rails View <%= form_for @article do |f| %> <p><%= f.text_field :subject %></p> <p><%= f.labeled_text_field :subject %></p> <p><%= f.text_field_with_errors :subject %></p> <p><%= f.labeled_text_field_with_errors :subject %></p> <%= f.submit %> <% end %>
Rails View <%= form_for @article do |f| %> <p><%= f.text_field :subject %></p> <p><%= f.labeled_text_field :subject %></p> <p><%= f.text_field_with_errors :subject %></p> <p><%= f.labeled_text_field_with_errors :subject %></p> <%= f.submit %> <% end %>
Rails View  <p><input id="article_subject" name="article[subject]" size="30" type="text" value="" /></p> <p><label for="article_subject">Subject</label> <input id="article_subject" name="article[subject]" size="30" type="text" value="" /></p> <p><input id="article_subject" name="article[subject]" size="30" type="text" value="" /> <span class="error">can't be blank</span></p> <p><label for="article_subject">Subject</label> <input id="article_subject" name="article[subject]" size="30" type="text" value="" /> <span class="error">can't be blank</span></p>
Inspire Theme Songs About Your Work http://www.confreaks.com/videos/529-farmhouseconf-ruby-hero-tenderlove 37
The Router and Controllers They carry the theme of our
applications
Route Exceptions From José Valim 38 # ... module Blog
class Application < Rails::Application # ... config.exceptions_app = routes end end
class Application < Rails::Application # ... config.exceptions_app = routes end end
class Application < Rails::Application # ... config.exceptions_app = routes end end Blog::Application.routes.draw do # ... match "/404", to: "errors#not_found" end
class Application < Rails::Application # ... config.exceptions_app = routes end end Blog::Application.routes.draw do # ... match "/404", to: "errors#not_found" end
Route to Sinatra From Crafting Rails Applications 39 source 'https://rubygems.org'
# ... gem "resque", require: "resque/server"
# ... gem "resque", require: "resque/server"
# ... gem "resque", require: "resque/server" module AdminValidator module_function def matches?(request) if (id = request.env["rack.session"]["user_id"]) current_user = User.find_by_id(id) current_user.try(:admin?) else false end end end
Route to Sinatra From Crafting Rails Applications 39 Blog::Application.routes.draw do
# ... require "admin_validator" constraints AdminValidator do mount Resque::Server, at: "/admin/resque" end end
Stream CSV to Users 40 class ArticlesController < ApplicationController def
index respond_to do |format| format.html do @articles = Article.all end format.csv do headers["Content-Disposition"] = %Q{attachment; filename="articles.csv"} self.response_body = Enumerator.new do |response| csv = CSV.new(response, row_sep: "\n") csv << %w[Subject Created Status] Article.find_each do |article| csv << [ article.subject, article.created_at.to_s(:long), article.status ] end end end end end # ... end
Do Some Work in the Background From Crafting Rails Applications
41 $ rails g migration add_stats_to_articles stats:text
41 $ rails g migration add_stats_to_articles stats:text
41 class Article < ActiveRecord::Base # ... serialize :stats def calculate_stats words = Hash.new(0) body.to_s.scan(/\S+/) { |word| words[word] += 1 } sleep 10 # simulate a lot of work self.stats = {words: words} end end $ rails g migration add_stats_to_articles stats:text
41 class Article < ActiveRecord::Base # ... serialize :stats def calculate_stats words = Hash.new(0) body.to_s.scan(/\S+/) { |word| words[word] += 1 } sleep 10 # simulate a lot of work self.stats = {words: words} end end $ rails g migration add_stats_to_articles stats:text
41 class Article < ActiveRecord::Base # ... require "thread" def self.queue; @queue ||= Queue.new end def self.thread @thread ||= Thread.new do while job = queue.pop job.call end end end thread # start the Thread end
41 class Article < ActiveRecord::Base # ... after_create :add_stats def add_stats self.class.queue << -> { calculate_stats; save } end end
41 class Article < ActiveRecord::Base # ... after_create :add_stats def add_stats self.class.queue << -> { calculate_stats; save } end end
41 $ rails c Loading development environment (Rails 3.2.3) >> Article.create!(subject: "Stats", body: "Lorem ipsum…"); Time.now.strftime("%H:%M:%S") => "15:24:10" >> [Article.last.stats, Time.now.strftime("%H:%M:%S")] => [nil, "15:24:13"] >> [Article.last.stats, Time.now.strftime("%H:%M:%S")] =>[{:words=>{"Lorem"=>1, "ipsum"=>1, …}, "15:24:26"]
Have We All Learned Something New Yet?!
Publish a Static Site Using Rails 42 Static::Application.configure do #
... # Show full error reports and disable caching config.consider_all_requests_local = true config.action_controller.perform_caching = !!ENV["GENERATING_SITE"] # ... # Don't fallback to assets pipeline if a precompiled asset is missed config.assets.compile = !ENV["GENERATING_SITE"] # Generate digests for assets URLs config.assets.digest = !!ENV["GENERATING_SITE"] # ... end
Publish a Static Site Using Rails 42 Static::Application.configure do #
... # Show full error reports and disable caching config.consider_all_requests_local = true config.action_controller.perform_caching = !!ENV["GENERATING_SITE"] # ... # Don't fallback to assets pipeline if a precompiled asset is missed config.assets.compile = !ENV["GENERATING_SITE"] # Generate digests for assets URLs config.assets.digest = !!ENV["GENERATING_SITE"] # ... end
Publish a Static Site Using Rails 42 class ApplicationController <
ActionController::Base protect_from_forgery if ENV["GENERATING_SITE"] after_filter do |c| c.cache_page(nil, nil, Zlib::BEST_COMPRESSION) end end end
Publish a Static Site Using Rails 42 class ApplicationController <
ActionController::Base protect_from_forgery if ENV["GENERATING_SITE"] after_filter do |c| c.cache_page(nil, nil, Zlib::BEST_COMPRESSION) end end end
Publish a Static Site Using Rails 42 require "open-uri" namespace
:static do desc "Generate a static copy of the site" task :generate => %w[environment assets:precompile] do site = ENV.fetch("RSYNC_SITE_TO") { fail "Must set RSYNC_SITE_TO" } server = spawn( {"GENERATING_SITE" => "true"}, "bundle exec rails s thin -p 3001" ) sleep 10 # FIXME: start when the server is up # ... end
:static do desc "Generate a static copy of the site" task :generate => %w[environment assets:precompile] do site = ENV.fetch("RSYNC_SITE_TO") { fail "Must set RSYNC_SITE_TO" } server = spawn( {"GENERATING_SITE" => "true"}, "bundle exec rails s thin -p 3001" ) sleep 10 # FIXME: start when the server is up # ... end
:static do desc "Generate a static copy of the site" task :generate => %w[environment assets:precompile] do # ... # FIXME: improve the following super crude spider paths = %w[/] files = [ ] while path = paths.shift files << File.join("public", path.sub(%r{/\z}, "/index") + ".html") File.unlink(files.last) if File.exist? files.last files << files.last + ".gz" File.unlink(files.last) if File.exist? files.last page = open("http://localhost:3001#{path}") { |url| url.read } page.scan(/<a[^>]+href="([^"]+)"/) do |link| paths << link.first end end # ... end end
:static do desc "Generate a static copy of the site" task :generate => %w[environment assets:precompile] do # ... # FIXME: improve the following super crude spider paths = %w[/] files = [ ] while path = paths.shift files << File.join("public", path.sub(%r{/\z}, "/index") + ".html") File.unlink(files.last) if File.exist? files.last files << files.last + ".gz" File.unlink(files.last) if File.exist? files.last page = open("http://localhost:3001#{path}") { |url| url.read } page.scan(/<a[^>]+href="([^"]+)"/) do |link| paths << link.first end end # ... end end
:static do desc "Generate a static copy of the site" task :generate => %w[environment assets:precompile] do # ... system("rsync -a public #{site}") Process.kill("INT", server) Process.wait(server) system("bundle exec rake assets:clean") files.each do |file| File.unlink(file) end end end
:static do desc "Generate a static copy of the site" task :generate => %w[environment assets:precompile] do # ... system("rsync -a public #{site}") Process.kill("INT", server) Process.wait(server) system("bundle exec rake assets:clean") files.each do |file| File.unlink(file) end end end
Publish a Static Site Using Rails 42 $ rake static:generate
RSYNC_SITE_TO=/Users/james/Desktop
Publish a Static Site Using Rails 42 $ rake static:generate
RSYNC_SITE_TO=/Users/james/Desktop
Did you memorize that?!
Did you memorize that?! Slides: http://speakerdeck.com/u/jeg2 Twitter: @JEG2 Email: [email protected]
Thanks! Have fun using these Rails tricks