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Amazing things in Rails
@ka8725

Load gems precedence
config/application.rb:
config.plugins = [:devise, :i18n, :all]

* default precedence is alphabetical

Changing backtrace
config/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 syslog
Allows to log to the remote server
http://docs.seattlerb.org/SyslogLogger/

Redirecting routes
config/routes.rb:
match ��/google��, :to => redirect(��http://google.com��)

Collect complicated routes
config/routes.rb:
match ��items/list/*specs��, :controller => ��items��, :action => ��list��

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

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

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

Preview new record route
resources :reports do
new do
post :preview
end
end

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 do
resource :retraction
end

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::Base
attr_readonly :social_security_number
end

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 views
BilableWeek.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:rollback
rake 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 < AR
has_many :timesheets, :autosave => true
end

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

validates_acceptance_of

class Account < AR
validates_acceptance_of :privacy_policy, :terms_of_service
end

Creates virtual attributes automatically

validates on
class Report < AR
validates_presence_of :name, :on => :publish
end

report.valid? :publish

Validators for specific fields

Merging scopes

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

For this purpose you are able to use merge method too

Callback classes
class MarkAsDeleted
def self.before_destroy(model)
model.update_attribute(:deleted_at, Time.now)
false
end
end

class Account < AR
before_destroy MarkAsDeleted
end

class Invoice < AR
before_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 ��Դǳٳ�ٲ��

Check defined local variables in
partials

local_assigns.has_key? :special

Entry counter in the partials

= div_for(entry) do
span ##{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>

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