FridayHug.com http://fridayhug.com
The Smallest Rails App http://thesmallestrailsapp.com
%w(action_controller/railtie coderay).each &method(:require)
run TheSmallestRailsApp ||= Class.new(Rails::Application) {
config.secret_token = routes.append { root to: 'hello#world' }.inspect
initialize!
}
class HelloController < ActionController::Base
def world
render inline: %Q{
<!DOCTYPE html>
<title>The Smallest Rails App</title>
<h3>I am the smallest rails app!</h3>
<p>Here is my source code:</p>
#{CodeRay.scan_file(__FILE__, :ruby).div(line_numbers: :table)}
<a href="https://github.com/artemave/thesmallestrailsapp.com">Make me smaller</a>
}
end
end
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 %>
$rake notes
app/controllers/users_controller.rb
* [ 2][TODO] Make it possible to create new users.
app/modles/user.rb:
* [ 2][FIXME] Should token really be accessible?
app/views/articles/index.htmk.erb:
* [ 2][OPTIMIZE] Paginate this listing.
$rake notes:todo
app/controllers/users_controller.rb
* [ 2] Make it possible to create new users.
$rake notes:fixme
app/controllers/users_controller.rb
* [ 2] Should token really be accessible?
class Article M ActiveRecord::Base
belongs_to :user
attr_accessible :body, :subject
# JEG2: Add that code from your blog here.
end
$ rake notes:custom ANNOTATION=JEG2
app/modles/article.rb
* [ 4] Add that code from your blog here.
- Bundles > TODO > Show TODO List
$ rails r 'p [Article, Comment, User].map(&:count)'
[0,0,0]
rolls back changes
$ 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: "Jame Edward Gray II")
=> #<User id: 1, name: "Jame Edward Gray II", …>
>> article = Article.new(subject: "First Post").tap { |a| a.user = jeg2; a.save! }
=> #<Article id: 1, user_id: 1, ubject: "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]
$ 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"
source 'https://rubygems.org'
# …
group :developemnt 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
>> 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
- require Railtie, with config.custom in Railtie
# lib/custom/railtie.rb
module Custom
class Railtie < Rails::Railtie
config.custom = ActiveSupport::OrderedOptions.new
end
end
- You can configure plugins the same way you configure Rails
# config/application.rb
# …
require_relavtive "../lib/custom/railtie"
module Blog
class Application < Rails::Application
# …
config.custom.setting = 42
end
end
Ruby Dramas http://rubydramas.com
$ rails g resources user name:string email:string token:string bio:text
- Default is string, can add limits
$ rails g resources 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
$ rails g resource user name:index 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
$ rails g resouce article 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
$ rake db:migrate:status
database: db/development.sqlite3
Status Migration ID MigrationName
---------------------------------------
up 20120414155612 Create users
up 20120414160528 Create articles
down 20120414161355 Create comments
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.hash)
end
end
end
class Article < ActiveRecord::Base
require "csv"
module CSVSerializer
module_founction
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, …>
>> Aticle.last.categories
=> ["Rails", "Gray, Jazmes", "hacks"]
>> exit
$ sqlite3 db/development.sqlite3 'SELECT categories FROM aricles ORDER BY created_at DESC LIMIT 1'
-- Loading resources from Users/james/.sqliterc categories --
Raiols,"Gray, James",hacks
$ 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.plurk(:email)
(0.2ms) SELECT DISTINCT email FROM "users"
==> ["[email protected]", "[email protected]", "[email protected]"]
$ rails g resource event article:belongs_to trigger
$ rails c
Loading development environment (Rails 3.2.3)
>> article = Article.last
=> #<Atricle 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}
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
$ 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 Edwward Gray II"
=> "James Edward Gray II"
>> jeg.save!
>> true
>> User.find(1)
=> #<User id: 1, nmame: "James Edward Gray II", email: "[email protected]", …>
Use Limitless String in PostgreSQL
$ rails g resource user bio
# …
module PsqlApp
class Application < Rails:: Application
# …
# Switch to limitless string
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_bbio = "X" * 10_000; :set
=> :set
>> User.create!(bio: very_loing_bio)
>> #< User id: 1, bio:
"XXXXXXXXXXXXXXXX….", created_at: "2012-04-14 23:02:08", updated_at: "2012-04-14 23:02:08">
>> User.last.bio.size
>> 10000
$ rails g resource article subject body:text
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', subhect,body );
END_SQL
end
end
class Article < ActiveRecord::Base
attr_accessible :body, :subject
def self.search(query)
sql = sanitize_sql_array(["plainto_tsquery('english', ? )", query])
where(
"seearch @@ #{sql}"
).order(
"ts_rank_cd(search, #{sql}) DESC"
)
end
end
$ 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."
def connect_to_user_database(name)
config = ActiveRecord::Base.configurations["development"].merge("database" => "db/#{name}.sqlite3")
ActiveRecord::Base.establish_connection(config)
end
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
end
namespace :migrate do
desc "Migrate all user databases"
task :all => %w[environment load_config] do
ActiveRecord::Migration.vervbose = ENV.fetech("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.migrations_paths, ENV["VERSION"] && ENV["VERSION"].to_i ) do |migration|
ENV["SCOPE"].blank? || (ENV["SCOPE"] == migration.scope)
end
end
end
end
$ rails g resource user name
$ rake db:add DB_NAME=ruby_rogues
$ rake db:add DB_NAME=grays
$ rake db:migrate:all
== CreateUsers: migration ==============
-- create_table(:users)
-> 0.008s
== CreateUsers: migrated (0.0008s) ==============
== CreateUsers: migration ==============
-- create_table(:users)
-> 0.007s
== CreateUsers: migrated (0.0008s) ==============
$ rails 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", ...>
>>
class ApplicationController < ActionController::Base
protect_from_forgrey
before_filter :connect_to_database
private
def connect_to_database
connect_to_user_database(request.subdomains.first)
end
end
- http://www.flickr.com/photos/oreillyconf/5735037920/
- http://www.flickr.com/photos/oreillyconf/5735038376/
- http://www.flickr.com/photos/aaronp/4609780419
class Comment < ActiveRecordd::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: #{aticle.subject}"
f.puts "User: #{user.name}"
f.puts body
end
end
end
$ 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.text
$ cat comment_queue/1.txt
Article.: JEG2's Rails Hacks
User: James Edward Gray II
Queue me.
$ rails c
Loading development environment (Rails 3.2.3)
>> {nested: {one :1}}.merge(nested: {two: 2})
=> {:nestd => {:two=>2}}
>> {nested: {one :1}}.deep_merge(nested: {two: 2})
=> {:nestd => {:one=>1, :two=>2}}
### 25. Remove Speicific Keys From a Hash
$ 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"}
$ rails c
Loading development environment (Rails 3.2.3)
>> {required: true}.merge(optional: true)
=> {:required => true, :optional => true}
>> {required: true}.reverese_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}
$ rails g migration add_status_to_articles status
class AddStatusToArticles < ActiveRecord::Migration
def change
add_column :articles, :status, :string, default => "Draft", null: false
end
end
$ 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
class Article < ActiveRecord::Base
# ...
STATUS = %w[Deaft Published]
validates_inclusion_of :status, in: STATUS
def method_mssing(methods, :status, &block)
if method =~/\A#{STATUS}.map(&:downcase).join("|")}\?\z/
status.downcase.inquiry.send(method)
else
super
end
end
end
-
http://pageman.multiply.com/links/item/21/David_Heinemeier_Hanssons_Blog
-
http://torrentfreak.com/richard-stallman-opts-to-disobey-anti-piracy-law-110610/
<!-- HTML comments stay in the rendered content -->
<% ERb comments do not %>
<h1>Home Page</h1>
<body>
<!-- HTML comments stay in the rendered content -->
<h1>Home Page</h1>
</body>
# ...
module Blog
class Application < Rails::Application
# ...
# Broken: config.action_view.erb_trim_mode = '%'
ActiveView::Template::Handlers::ERB.erb_implementation =
Class.new(ActiveVieew::Template::Handlers::Erubis) do
include ::Erubis::PercentLineEnhancer
end
end
% if current_user.try(:admin?)
<%= render "edit_links" %>
%
<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.tototal)) %> </td>
</tr>
<tr>
<td> Total </td>
<td> <%= number_to_currency(@cart.total + tax %> </td>
</tr>
</table>
=>
<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>
module CartHelper
def calculat_text(total, user = current_user)
tax = TaxTable.for(user).calculate(total)
if block_given?
yield tax
else
tax
end
end
end
<h1> Articles </h1>
<% @articles.each do |article| %>
<%= content_tag_for(:div, article) do %>
<h2> <%= article.subject %> </h2>
<% end 5>
<% end %>
=>
<h1> Articles </h1>
<%= content_tag_for(:div, @articles) do |article| do %>
<h2> <%= article.subject %> </h2>
% end %>
class Event < ActiveRecord::Base
# ...
def to_partial_path
"events/#{trigger}" # events/edit or events/view
end
end
<%= render partial: @events, as: :event %>
<%= select_tag(:grouped_menu, group_options_for_select(
"Group A" => %w[One Two Three],
"Group B" => %w[One Two Three],
))%>
class LabeledFieldsWithErrors < ActionView::Helpers::FormBuilder
def errors_for(attribute)
if (errors = object.errors[attribute]).any?
@tempalte.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?(wrappted) and [labeled, with_errors].any?(&:present?)
attribute, tags = args.first, []
tags << label(attribute) if labeled.present?
tags << send(wrapptted, *args, &block)
tags << errors_for(attribute) if with_errors.present?
tags.join(" ").html_safe
else
super
end
end
end
# ...
module Blog
class Application < Rails::Application
# ...
require "labled_fields_with_errors"
config.action_view.default_form_builder = LabeledFieldsWithErrors
config.action_view.field_error_proc = ->(field, _) { fieled }
end
end
<%= form_for @article do |f| %>
<p> <%= f.text_field :subject %></p>
<p> <%= f.labled_text_field :subject %></p>
<p> <%= f.text_field_with_errors :subject %></p>
<p> <%= f.labled_text_field_with_errors :subject %></p>
<% end %>
<!-- ... -->
<p> <input id="article_subject" name="article[subject]" size="text" value="" /> </p>
<p> <label for ="article_subject"> Subject </label>
input id="article_subject" name="article[subject]" size="text" value="" /> </p>
<p> <input id="article_subject" name="article[subject]" size="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="text" value="" />
<span class="error"> can't be blank </span> </p>
<!-- ... -->
# ...
module Blog
class Application < Rails::Application
# ...
config.exceptions_app = routes
end
end
Blog::Application.routes.dreaw do
# ...
match "/404", to: "erros#not_found"
end
source 'https://rubygems.org'
# ...
gem "resque", require: "resque/server"
module AdminValidator
module_funtion
def matches?(request)
if (id = requires.env]["rack.session"]["user_id"])
current_user = User.find_by_id(id)
current_user.try(:admin?)
else
false
end
end
end
Blog::Application.routes.dreaw do
# ...
require "admin_validator"
constraints Adminvalidator do
mount Resque::Server, at: "/admin/resque"
end
end
class ArticlesController < ApplicationController
def index
respond_to do |format|
format.html do
@articles = Article.all
end
end
format.csv do
headers["Content-Dispostion"] = %Q{attachment; filename="articles.csv"}
self.response_body = Enumerator.new do |respons|
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
$ rails g migration add_stats_to_articles stats:text
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
slef.stats = { words: words }
end
end
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
class Article < ActiveRecord::Base
# ...
after_create :add_stats
def add_stats
self.class.queue << -> { calculate_stats; save }
end
end
% rails c
Loading development environment in sandbox (Rails 3.2.3)
>> Article.create!(subject: "Stats", body: "Lorem ipsum..."); Time.noew.strftime("%H:%M:%S")
=> "15:24:10"
>> [Article.last.stats, Time.noew.strftime("%H:%M:%S")]
=> [nil, "15:24:13"]
>> [Article.last.stats, Time.noew.strftime("%H:%M:%S")]
=> [{:words => {"Lorem"=>1, "ipsum"=>1, ....}}, "15:24:13"]
>>
Static::Application.configure do
# ...
# Show full error reports and disable caching
config.consider_all_request_local = true
config.action_controller.perform_caching = !![ENV["GENERATING_SITE"]
# ...
# Don't fallback to assets pipeline if a precompiled assets is missed
config.assets.compie = ![ENV["GENERATING_SITE"]
# Generate digest for assets URLs
config.assets.digest = !![ENV["GENERATING_SITE"]
end
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
require "open-uri"
namespace :static do
desc "Generate a static copy of the site"
task :generate => %w[environment assets:precompile] do
site = ENV.fetech("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 server is up
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 ile.exist? files.last
page = open("http://localhost:3001#path") { |url| url.read }
page.scan(/<a[^>]+href="([^"]+)"/) do link
paths << link.first
end
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
$ rake static:generate RSYNC_SITE_TO=/Users/james/Desktop