Rails3 way

Amazing things in Rails@ka8725

Load gems precedenceconfig/application.rb:

config.plugins = [:devise, :i18n, :all]

* default precedence is alphabetical

Changing backtraceconfig/initializers/backtrace_silencer.rb:Rails.backtrace_cleaner.add_silencer { |line| line =~ /my_noisy_library/ }

Rails.backtrace_cleaner.remove_silencers!

List of loaded gems$ rails c>> $LOAD_PATH

=>[“/usr/local/lib/ruby/...”, ...]

Log to syslog

Allows to log to the remote server

http://docs.seattlerb.org/SyslogLogger/

Log to syslogAllows to log to the remote serverhttp://docs.seattlerb.org/SyslogLogger/

Redirecting routes

match ‘/google’, :to => redirect(‘http://google.com’)

config/routes.rb:

Collect complicated routesmatch ‘items/list/*specs’, :controller => ‘items’, :action => ‘list’

config/routes.rb:

/items/list/base/books/fiction/dickens/little_dorrit

params[:specs] # => “base/books/fiction/dickens/little_dorrit”

List of controller routes$ rake routes CONTROLLER=productsWill show the list of ProductsController routes

Preview new record routeresources :reports donew do

post :previewendend

preview_new_report POST /reports/new/preview(.:format) {:action => ‘preview’, :controller => ‘reports’}

= form_for(report, :url => preview_new_report_path) do |f|...= f.submit ‘Preview’

Avoid member actions

resources :bids doresource :retractionend

Verify instead of before_filter

verify :params => ‘privileges’, :only => :update, :redirect_to => {:action => ‘settings’}

* Redirects to setting action unless privileges param key presents

Read attributes before type casting

<attribute_name>_before_type_cast

* Example: @user.phone_before_type_cast

Read only attributes

class Customer < ActiveRecord::Baseattr_readonly :social_security_numberend

Get random record

Timesheet.limit(1).offset(rand(Timesheet.count)).first

Select all attributes with calculated values

BilableWeek.select(:*, “mon_hrs + tues_hrs as two_day_total”)

* Pay attention on :*

Method “from” in the selects to join tables or viewsBilableWeek.select(“...”).from(“users”).where(“users.name = ‘John’”)

Method ‘exists?’ in AR

User.exists?(1)

User.find_by_id(1).present?

Use Time instead of DateTime

Time is faster because it is written in C

Redo migration

rake db:migrate:redo

It’s the same as:

rake db:rollbackrake db:migrate

Difference between << and create on the associations<< is transactional, but create is not

<< triggers :before_add and :after_add callbacks but create doesn’t

Method ‘clear’ on the associations

Transactionally removes all records and triggers callbacks

Reloading associations

User.locations(true)

insert_sql and delete_sql options for associations

Convenient way to avoid callbacks

* Please, reference to rails doc

:autosave => true

class User < ARhas_many :timesheets, :autosave => trueend

user = User.firstuser.timesheets.first.mark_for_destrictionuser.save # will delete timesheet record

validates_acceptance_of

Creates virtual attributes automatically

class Account < ARvalidates_acceptance_of :privacy_policy, :terms_of_service

end

validates on

Validators for specific fields

class Report < ARvalidates_presence_of :name, :on => :publishend

report.valid? :publish

Merging scopes

For this purpose you are able to use merge method too

scope :tardy, :lambda {joins(:timesheets).group(“users.id”) & Timesheet.late}

Callback classesclass MarkAsDeleted

def self.before_destroy(model)model.update_attribute(:deleted_at, Time.now)false

endend

class Account < ARbefore_destroy MarkAsDeleted

end

class Invoice < ARbefore_destroy MarkAsDeleted

end

Callback classesclass MarkAsDeleted

def self.before_destroy(model)model.update_attribute(:deleted_at, Time.now)false

endend

class Account < ARbefore_destroy MarkAsDeleted

end

class Invoice < ARbefore_destroy MarkAsDeleted

end

Calculation methods#average#count#maximum#minimum#sum

Person.calculate(:count, :all)Person.average(:age)Person.minimum(:age).where(‘last_name <> ?’, ‘John’)

STI another column

set_inheritance_column ‘not_type’

Check defined local variables in partials

local_assigns.has_key? :special

Entry counter in the partials

= div_for(entry) dospan ##{entry_counter}span #{entry.name}

Many asset hosts

config.action_controller.asset_host = Proc.new { |source|

“http://assets#{rand(2) + 1}.example.com”}

number_to_phone method

number_to_phone(1235551234) #=> “123-555-1234”

auto_link method

auto_link(“Go to http://google.com. Email: test@email.com”)

=> Go to <a href=”http://google.com”>http://google.com</a>. Email: <a href=”mailto:test@email.com”>text@email.com</a>