The Most Intelligent Ruby IDE
JetBrains RubyMine — Ruby and Rails IDE with the full stack of essential developer tools, all tightly integrated together and creating a convenient and smart environment for Ruby programming and Web development with Ruby on Rails.

Help and documentation for the Ruby programming language.

Command line cheat sheets

Provides a set of methods for making links and getting URLs that depend on the routing subsystem (see ActionController::Routing). This allows you to use the same format for links in views and controllers

This guide covers the association features of Active Record. By referring to this guide, you will be able to:
* Declare associations between Active Record models
* Understand the various types of Active Record associations
* Use the methods added to your models by creating associations

Associations are a set of macro-like class methods for tying objects together through foreign keys. They express relationships like "Project has one Project Manager" or "Project belongs to a Portfolio". Each macro adds a number of methods to the class which are specialized according to the collection or association symbol and the options hash. It works much the same way as Ruby‘s own attr* methods.