rails translating attribute names

I found the answer to my question from here.
Here’s the way:

  activerecord:
    attributes:
      user:
        first_name: "Name first"

making sure your integration tests view the actual data in the db

Monkeypatch ActiveRecord with this:

class ActiveRecord::Base
  mattr_accessor :shared_connection
  @@shared_connection = nil

  def self.connection
    @@shared_connection || retrieve_connection
  end
end

and your spec_helper with this:

RSpec.configure do |config|
  config.use_transactional_fixtures = false

  config.before :each do
    if Capybara.current_driver == :rack_test
      DatabaseCleaner.strategy = :transaction
    else
      DatabaseCleaner.strategy = :truncation
    end
    DatabaseCleaner.start
  end

  config.after do
    DatabaseCleaner.clean
  end
end

Full info available on Nicholas Rutherford’s blog. Thanks Nicholas!

rails select only some columns

If you want to only select a few columns on a query, here’s how you can do it:

 YourModel.find(:all,:select => "column1,column2") 

access the database of a heroku application from another heroku application

First thing you have to do is find out the DATABASE_URL of the app you’re interested in. Run heroku config –app your_app to get it. Then, in the other app, run this:

heroku config:add DATABASE_URL=whatever_the_result_of_the_first_command_was

Establish an ActiveRecord connection:

  db = URI.parse(ENV['DATABASE_URL'] || 'postgres://localhost/mydb')

  ActiveRecord::Base.establish_connection(
              :adapter  => db.scheme == 'postgres' ? 'postgresql' : db.scheme,
              :host     => db.host,
              :username => db.user,
              :password => db.password,
              :database => db.path[1..-1],
              :encoding => 'utf8'
   )

cool ruby gem

state_machine is a nifty gem. Try it!

using coffeescript on windows

If you want to develop with CoffeeScript outside of Rails, here’s one way you could do it:

• download the coffee.exe executable from CoffeeScript compiler for Windows
• copy coffee.exe in a folder that is on the PATH
• create a watchr file, for the ruby gem watchr. This way, everytime you modify the .coffee file, the js file gets recompiled. Here are the contents of my watchr file:

  
  watch("js/application.coffee") do |s|
  	puts "#{Time.now} => Compiling #{s}"
  	system("coffee -c #{s[0]}")
  end
  

• start watching the file for modifications:

  
  watcher your_watch_file.rb
  
  
  

• add the include for the resulting JS in your html code and you’re done

running a single test with rspec

Assuming 31 is the line at which your test starts, do this:

rspec some.spec:31

some treetop debug tips

Treetop seems pretty nice, but information on it’s usage is kind of scattered all over internet . Here are a few tips that I used to debug grammars:

1. You can try a specific rule by writing this:
   
tree = parser.parse(content,:root => "rule_name")

2. I usually have my code structured like this, to get some info about where the parser chokes:

   
   if tree
       puts "succesful"
   else
       puts "unsuccesful at #{parser.index}"
       puts parser.failure_reason
   end
   

Hope this helps you as much as it helped me.