Getting Started with Rails 4

With a new major version of Rails -on the horizon- now released it makes sense to start taking a look and what’s going on. I’m going to show you how to install the Rails 4 gem so you can start playing with the latest version.

Setup your development environment

If you are new to Rails then you will might want to check out my other post about setting up a Ruby on Rails development environment on OS X as the following steps will assume a similar setup.

Installing Rails 4

Rails 4 is now the latest stable release so it’s much easier to get going with it.

gem install rails
rbenv rehash # if you're using rbenv

Once the gem installer has done it’s thing you can now check the Rails version with rails -v and start a new project in the usual way.

rails new myproject

# Or if you crave the bleeding edge from the repo
rails new myproject --edge

How to create a Rails 3 project with Rails 4 installed

With Rails 4 now taking priority over Rails 3 in your gem list how do you make a new Rails 3.2 project without going through the hassle of uninstalling Rails 4.

Simple really, check the versions of Rails you have installed already with gem list rails.

*** LOCAL GEMS ***
rails (4.0.0, 3.2.13)

The output shows I have the Rails 4.0.0 and 3.2.13 installed and you can simply append that version number to your rails command like so.

rails _3.2.13_ new myproject

This will create a project in the usual way but this time using the 3.2.13 version of the gem.

Don’t forget that you should use bundle exec within your project when calling rails generate and friends so that the correct gem version according to the projects Gemfile is used. For example: bundle exec rails generate model User.

Find out more about what’s new in Rails 4

The Rails team have made a number of changes, improvements and deprecations that I’m not going to go into here but instead direct you to the following resources to learn more: