Rails Script

Sometimes I want to write a ruby script that uses the models or other things in the Rails application. The simplest way to do it is to write a little script and executes it with Rails script runner. But what if the script is more than a few lines of code and needs to be able to handle multiple arguments? Let’s say I want to build a thrift server that uses Rails models and put it under Rails.root/script folder:

#!/usr/bin/env ruby
require 'optparse'

# Default options
app_config = { :environment => "development" }

# Parses options
OptionParser.new do |opts|
  opts.on("-e", "--environment=name", String,
          "Specifies the environment for the server to operate under (test/development/production).",
          "Default: development") { |v| app_config[:environment] = v }
  opts.on("-p", "--port=name", Integer,
          "Runs thrift server on the specific port.",
          "Default: 9090") { |v| app_config[:port] = v }
end.parse!

ENV["RAILS_ENV"] ||= app_config[:environment]

STDOUT.sync = true

# Loads Rails environment
require File.expand_path('../../config/boot',  __FILE__)
require File.expand_path("../../config/environment", __FILE__)

app_config = YAML::load(ERB.new(IO.read(File.join(Rails.root,
  'config/app.yml'))).result)[Rails.env].with_indifferent_access.merge(app_config)

port = app_config[:port] || 9090
thread_count = app_config[:thread] || 1

# Includes thrift-generated code
$:.push("#{Rails.root}/app/thrift")

class AppServiceHandler
  
  def initialize(options = {})
    ...
  end
  
  ...

end

handler = AppServiceHandler.new(app_config)
processor = AppService::Processor.new(handler)
transport = Thrift::ServerSocket.new(port)
transportFactory = Thrift::BufferedTransportFactory.new()
protocolFactory = Thrift::BinaryProtocolFactory.new()
server = Thrift::ThreadPoolServer.new(processor, transport, transportFactory, protocolFactory, thread_count)
server.serve()

JavaScript Alert Dialog is ugly

Rails uses JavaScript alert by default for confirmations, and developers love using alert() because it is easy. Downside? I think it feels cheap. There are tons of solution out there, jQuery UI, ColorBox. In case you are using Twitter’s Bootstrap (isn’t it the best thing ever?), it’s pretty easy to replace using native JavaScript alert dialog with Twitter modal dialog.

Here is how I replace the alert() function using CoffeeScript:

# Public: Shows a modal dialog in replacement of JavaScript alert.
#
# title - Title on the dialog (required).
# message - Message on the dialog (required).
# label - Label for the dismiss button (optional).
#
# Returns jQuery Object for the modal dialog.
#
YourApplication.alert = (title, message, label) ->
  $alert = $('#application_alert')
  if $alert.length == 0
    html =  """
            <div class="modal hide fade" id="application_alert">
              <div class="modal-header">
                <button type="button" class="close" data-dismiss="modal">&times;</button>
                <h3></h3>
              </div>
              <div class="modal-body">
                <p></p>
              </div>
              <div class="modal-footer">
                <a href="#" class="btn" data-dismiss="modal"></a>
              </div>
            </div>
            """
    $alert = $(html).appendTo($('body'))
  $('h3', $alert).text(title)
  $('p', $alert).text(message)
  $('a', $alert).text(label || 'Close')
  $alert.modal('show')

So instead of calling alert(…), you can call YourApplication.alert(…).

Next thing is I want to replace JavaScript confirm with Bootstrap modal dialog:

# Extends Rails JavaScript to use modal dialog for confirm.
$.rails.allowAction = (element) ->
  message = element.data('confirm')
  title = element.data('confirm-title') || 'Are you sure?'
  ok = element.data('confirm-ok') || 'OK'
  # If there's no message, there's no data-confirm attribute,
  # which means there's nothing to confirm
  return true unless message
  $('#confirmModal').remove()
  # Clone the clicked element (probably a delete link) so we can use it in the dialog box.
  $link = element.clone()
    # We don't necessarily want the same styling as the original link/button.
    .removeAttr('class')
    # We don't want to pop up another confirmation (recursion)
    .removeAttr('data-confirm')
    # We want a button
    .addClass('btn').addClass('btn-danger')
    # We want it to sound confirmy
    .html(ok)

  # Create the modal box with the message
  modal_html = """
               <div class="modal fade" id="confirmModal">
                 <div class="modal-header">
                   <a class="close" data-dismiss="modal">×</a>
                   <h3>#{title}</h3>
                 </div>
                 <div class="modal-body">
                   <p>#{message}</p>
                 </div>
                 <div class="modal-footer">
                   <a data-dismiss="modal" class="btn">Cancel</a>
                 </div>
               </div>
               """
  $modal_html = $(modal_html)
  # Add the new button to the modal box
  $modal_html.find('.modal-footer').append($link)
  # Pop it up
  $modal_html.modal()
  # Prevent the original link from working
  return false

So now you can use the following in your erb file:

 <%= link_to "Jump", @jump,
      :confirm => "Are you sure you want to jump off the cliff?",
      :data => { :confirm_title => "Think Twice" , :confirm_ok => "Jump" } %>

I hope this helps.

Guard with OS X Lion Notification

Since Lion has notification center built-in, I do not want to install Growl again. It would be great if I don’t have to switch between editor and terminal to see if all of my tests passed whenever I saved a file. Turned out, with the latest guard with Terminal notification, I got what I wished.

In case you don’t know what guard is, you should check out Ryan Bate’s Railscast on Guard.

Update your guard with bundle update guard, and add the following in your Gemfile:

group :development do
  ...
  gem 'terminal-notifier'
end

And… MONEY!

 

Testing Resque background jobs with RSpec

Let’s say you have a model which involves a background job upon save, or you want to schedule a background job in the controller, how to do you make sure the background will run correctly? One way is to use expectation mock like Resque.should_receive(:enqueue).with(…), but a simpler/better way is just put the following in your before…end block:

Resque.inline = true

That will run your background job right away.

Remember me, devise, and omniauth

This is how you do remember_me with Devise and Omniauthable, this is the OmniauthCallbacksController in one of my apps:

class OmniauthCallbacksController < Devise::OmniauthCallbacksController
  def facebook
    auth(:facebook)
  end

  def twitter
    auth(:twitter)
  end

protected
  def auth(provider)
    auth_hash = request.env['omniauth.auth']
    @user = User.find_for_omniauth(provider, auth_hash, current_user)

    if @user.persisted?
      flash[:notice] = I18n.t "devise.omniauth_callbacks.success", :kind => provider
      @user.remember_me = true
      sign_in_and_redirect @user, :event => :authentication
    else
      session['devise.omniauth'] = auth_hash.except('extra')
      redirect_to new_user_registration_url
    end
  end
end