Get the stable version of rvm:
$ rvm get stable
Install Ruby 2.0
$ rvm install ruby-2.0.0
Create a Gemset;
$ rvm gemset create rails-4.0
Goto that gemset:
$ rvm use email@example.com
Install Rails 4.0
$ gem install rails --version=4.0
Create an rvmrc file in root folder:
$ vim rvmrc
$ rvm --rvmrc use firstname.lastname@example.org
uncomment the line gem ‘therubyracer’, platforms: :ruby from Gemfile
Start the server:
$ rails s
You are ready to go!!
Changes that you may need to perform while working with Rails 4 compared to old versions:
1. Check here for the New changes in Rails 4
2. If you are using devise gem use devise version 3 or above (http://blog.plataformatec.com.br/2013/05/devise-and-rails-4/)
Even if we are specified the database configuration for adapter in our database.yml, sometimes we are getting the error “database configuration does not specify adapter”. Usually you are doing the command for development
$ rake assets:precompile -t
And in your database.yml, configuration for development is specified. But if you are doing
$ rake assets:precompile -t RAILS_ENV=development
then you can see the error goes.
Another way is check your database.yml for production database configuration is there or not. If you adds the production database configuration then also it works! Because while doing the precompile for assets without specifying the environment then it checks all environments db configuration.
Another way is add the following in your application.rb file
config.assets.initialize_on_precompile = false
then also it works.
Suppose you need to make a user ‘newuser’ as an owner and ‘newgroup’ as a group of a folder ‘FOLDER’, then
$ sudo chown -R newuser:newgroup FOLDER