How to play with ActiveModel validators in the rails console

1. bundle open activemodel
2. Open the validator.rb file.
3. You can see the comments that shows you how to mixin the validators. Once you mixin, you can add any validator and define a dummy method for the attribute to play with it in the irb:

class Person
  include ActiveModel::Validations
  SSN_REGEX = /your ssn regex goes here/
  validates_format_of :ssn, with: SSN_REGEX
 
 
  def ssn   
    111-11-1111
  end
end

4. Change the ssn method to invalid ssn to test your regex.
 

How to install Exception Notification gem in Rails 4.1

1. Add the gem to Gemfile:

gem 'exception_notification'



bundle install

2. In config/environments/production.rb:

Whatever::Application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[Whatever] ",
    :sender_address => %{"notifier" },
    :exception_recipients => %w{exceptions@example.com}
  }

3. Configure ActionMailer, in config/environments/production.rb:

I am using Sendgrid SMTP API so:

config.action_mailer.delivery_method = :smtp

If you have sendmail installed on the production server:

config.action_mailer.delivery_method = :sendmail

4. In production.rb:
config.action_mailer.perform_deliveries = true
config.action_mailer.raise_delivery_errors = true

How to install pdftk on Mac OS

You can download the installer from https://www.pdflabs.com/tools/pdftk-server/

After installation, open a new terminal and check installation:

$ pdftk --version

pdftk 2.02 a Handy Tool for Manipulating PDF Documents
Copyright (c) 2003-13 Steward and Lee, LLC - Please Visit: www.pdftk.com
This is free software; see the source code for copying conditions. There is
NO warranty, not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
$

How to create .ruby-version and .ruby-gemset in RVM

rvm --create --ruby-version use ruby-2.1.2@r42
Reference: Create .ruby-version and .ruby-gemset

How to install latest version of Rails

gem install rails --version=4.2.0.beta1

How to check if ElasticSearch is running

By default elastic search runs on port 9200.

$ curl http://localhost:9200
{
  "ok" : true,
  "status" : 200,
  "name" : "White Pilgrim",
  "version" : {
    "number" : "0.90.13",
    "build_hash" : "249c9c5e06765c9e929e92b1d235e1ba4dc679fa",
    "build_timestamp" : "2014-03-25T15:27:12Z",
    "build_snapshot" : false,
    "lucene_version" : "4.6"
  },
  "tagline" : "You Know, for Search"
}

1. gem install rest-client

require 'rest-client'
RestClient.get('http://localhost:9200')


$ irb
> require 'rest-client'
 => true
> x = RestClient.get('http://localhost:9200')
 => "{\n  \"ok\" : true,\n  \"status\" : 200,\n  \"name\" : \"White Pilgrim\",\n  \"version\" : {\n    \"number\" : \"0.90.13\",\n    \"build_hash\" : \"249c9c5e06765c9e929e92b1d235e1ba4dc679fa\",\n    \"build_timestamp\" : \"2014-03-25T15:27:12Z\",\n    \"build_snapshot\" : false,\n    \"lucene_version\" : \"4.6\"\n  },\n  \"tagline\" : \"You Know, for Search\"\n}\n"
> x['ok']
 => "ok"
> JSON.parse(x)
 => {"ok"=>true, "status"=>200, "name"=>"White Pilgrim", "version"=>{"number"=>"0.90.13", "build_hash"=>"249c9c5e06765c9e929e92b1d235e1ba4dc679fa", "build_timestamp"=>"2014-03-25T15:27:12Z", "build_snapshot"=>false, "lucene_version"=>"4.6"}, "tagline"=>"You Know, for Search"}

How to configure the secret_key_base in Rails 4.1

1. Define an environment variable in .bashrc or .profile on the server:

export SECRET_KEY_BASE='a long string generated by running rake secret'

2. In secrets.yml file :
secret_key_base=<%= ENV['SECRET_KEY_BASE'] %>

3. MyBlog::Application.config.secret_key_base = Rails.application.secrets.secret_key_base

Remember: After deployment all the old sessions will become invalid.

How to add lib directory to the load path in Rails 4.1

   Uncomment the line :  config.autoload_paths += %W(#{config.root}/lib) in application.rb

Installing Redis on Mac

~ $brew install redis
==> Downloading https://downloads.sf.net/project/machomebrew/Bottles/redis-2.8.9.mavericks.bottle.tar.gz
######################################################################## 100.0%
==> Pouring redis-2.8.9.mavericks.bottle.tar.gz
==> Caveats
To have launchd start redis at login:
    ln -sfv /usr/local/opt/redis/*.plist ~/Library/LaunchAgents
Then to load redis now:
    launchctl load ~/Library/LaunchAgents/homebrew.mxcl.redis.plist
Or, if you don't want/need launchctl, you can just run:
    redis-server /usr/local/etc/redis.conf
==> Summary
 /usr/local/Cellar/redis/2.8.9: 10 files, 1.3M