Hidden Features of Ruby on Rails [closed]

Answer 1

Funny feature is that array has special method for accessing its 42 element

a = []
a.forty_two

http://railsapi.com/doc/rails-v2.3.8/classes/ActiveSupport/CoreExtensions/Array/Access.html#M003045

Answer 2

integer.ordinalize is one little method that I just stumbled upon not to long ago.

1.ordinalize = "1st"
3.ordinalize = "3rd"

Answer 3

I'll start with one of my favorites. When calling a partial with a collection, instead of looping through your collection and calling it for each item, you can use this:

render :partial => 'items', :collection => @items

This will call the partial once per item, and pass a local variable item each time. You don't have to worry about nil checking @items either.

Answer 4

You can change the behaviour of a model for your test suite. Say you have some after_save method defined and you do not want it to happen in your unit tests. This is how it works:

# models/person.rb
class Person < ActiveRecord::Base

  def after_save
    # do something useful
  end

end


# test/unit/person_test.rb
require 'test_helper'

class PersonTest < ActiveSupport::TestCase

  class ::Person
    def after_save
      # do nothing
    end
  end

  test "something interesting" do
    # ...
  end
end

Answer 5

The returning block is a great way to return values:

def returns_a_hash(id)
  returning Hash.new do |result|
   result["id"] = id
  end
end

Will return a hash. You can substitute any other types as well.

Answer 6

Get everything printed with rake routes programmatically:

Rails.application.routes