An application template that creates a starter application for Rails 4.0 or Rails 3.2.
It’s the Rails generator on steroids. See the Rails Composer project page.
The Rails Composer application template is built from recipes provided by the rails_apps_composer gem. Need to customize the Rails Composer application template? Want to build your own application template? Use the rails_apps_composer gem.
If you’re new to Rails, see What is Ruby on Rails?, recommendations for a Rails tutorial, and a list of top resources for Ruby and Rails.
The RailsApps project provides example applications that developers use as starter apps. Hundreds of developers use the apps, report problems as they arise, and propose solutions. Rails changes frequently; each application is known to work and serves as your personal “reference implementation” so you can stay up to date. Each is accompanied by a tutorial so there is no mystery code. Support for the project, including all the example applications and free articles, comes from subscribers. Please purchase a subscription to the RailsApps tutorials if you can.
Follow the project on Twitter: @rails_apps. Please tweet some praise if you like what you’ve found.
Before running the Rails Composer tool, you need to install:
- The Ruby language (version 2.0.0)
- Rails 3.2 or Rails 4.0
Check that appropriate versions of Ruby and Rails are installed in your development environment:
$ ruby -v
$ rails -v
Be sure to read the article Installing Rails to make sure your development environment is set up properly.
To build a Rails application using the Rails Composer tool:
$ rails new myapp -m https://raw.github.com/RailsApps/rails-composer/master/composer.rb
Replace myapp with the name of your application.
The $ character indicates a shell prompt; don’t include it when you run the command.
You can use the -T flag to skip Test::Unit files or the -O flag to skip Active Record files:
$ rails new myapp -m https://raw.github.com/RailsApps/rails-composer/master/composer.rb -T -O
Skip Test::Unit if you plan to use RSpec for unit testing. Skip Active Record if you plan to use a NoSQL datastore with an ORM such as Mongoid.
See the “Troubleshooting” section below if you see errors. In general, you’ll avoid many problems if you create your application using RVM as described below.
I recommend using rvm, the Ruby Version Manager, to manage your Rails versions, as described in the Installing Rails article.
Here’s how to generate a new Rails application using the Rails Composer tool and RVM:
$ mkdir myapp $ cd myapp $ rvm use ruby-2.0.0@myapp --ruby-version --create $ gem install rails $ rails new . -m https://raw.github.com/RailsApps/rails-composer/master/composer.rb
You can add the -T flag to skip Test::Unit files or the -O flag to skip Active Record files. Skip Test::Unit if you plan to use RSpec for unit testing. Skip Active Record if you plan to use a NoSQL datastore with an ORM such as Mongoid.
Instead of installing Rails into the global gemset and running rails new, we’ll create a root directory for a new application, create a new gemset, install Rails, and then generate a starter application.
When we create the gemset, the option “—ruby-version” creates .ruby-version and .ruby-gemset files in the root directory. RVM recognizes these files in an application’s root directory and loads the required version of Ruby and the correct gemset whenever you enter the directory.
When we create the gemset, it will be empty (though it inherits use of all the gems in the global gemset). We immediately install Rails. The command gem install rails installs the most recent stable release of Rails.
Finally we run rails new .. We use the Unix “dot” convention to refer to the current directory. This assigns the name of the directory to the new application.
This approach is different from the way most beginners are taught to create a Rails application. Our approach makes it easy to create a project-specific gemset to avoid clashes between gem versions when using the Rails Composer tool.
Use Rails Composer to generate any of the example applications from the RailsApps project. You’ll be able to choose your own project name when you generate the app. Generating the application gives you additional options.
To build the example application, Rails must be installed in your development environment. Choices of starter applications will differ depending on whether you are using Rails 4.0 or Rails 3.2.
Here’s an example:
$ rails new myapp -m https://raw.github.com/RailsApps/rails-composer/master/composer.rb
The $ character indicates a shell prompt; don’t include it when you run the command.
You can use the -T flag to skip Test::Unit files or the -O flag to skip Active Record files:
$ rails new myapp -m https://raw.github.com/RailsApps/rails-composer/master/composer.rb -T -O
This creates a new Rails app named myapp on your computer. You can use a different name if you wish.
You’ll see a prompt:
question Install an example application for Rails 4.0?
1) Build a RailsApps starter application
2) Build a contributed application
3) I want to build my own application
Enter “1” to select Build a RailsApps starter application. You’ll see a prompt:
question Starter apps for Rails 4.0. More to come.
1) learn-rails
2) rails-bootstrap
Make your choice. The Rails Composer tool may give you other options (other applications may have been added since these notes were written).
The application generator template will ask you for additional preferences:
question Web server for development?
1) WEBrick (default)
2) Thin
3) Unicorn
4) Puma
question Web server for production?
1) Same as development
2) Thin
3) Unicorn
4) Puma
question Template engine?
1) ERB
2) Haml
3) Slim
question Continuous testing?
1) None
2) Guard
extras Set a robots.txt file to ban spiders? (y/n)
extras Use or create a project-specific rvm gemset? (y/n)
extras Create a GitHub repository? (y/n)
We recommend Thin in development for speed and less noise in the log files.
If you plan to deploy to Heroku, select Thin as your production webserver. Unicorn is recommended by Heroku but configuration is more complex.
The example application uses the default “ERB” Rails template engine. Optionally, you can use another template engine, such as Haml or Slim. See instructions for Haml and Rails.
If you are a beginner, you won’t need “continuous testing.” If you like to use Guard, you can select it.
Set a robots.txt file to ban spiders if you want to keep your new site out of Google search results.
It is a good idea to use RVM, the Ruby Version Manager, and create a project-specific rvm gemset (not available on Windows). See Installing Rails.
If you choose to create a GitHub repository, the generator will prompt you for a GitHub username and password.
If you choose “I want to build my own application,” you will get a wide set of choices.
These options are for experienced developers. Expect to spend time debugging your starter application as not all options are tested or fully supported.
Here’s an example of what you’ll see using Rails 3.2:
question Install an example application?
1) I want to build my own application
2) membership/subscription/saas (Stripe or Recurly)
3) rails-prelaunch-signup
4) rails3-bootstrap-devise-cancan
5) rails3-devise-rspec-cucumber
6) rails3-mongoid-devise
7) rails3-mongoid-omniauth
8) rails3-subdomains
question Web server for development?
1) WEBrick (default)
2) Thin
3) Unicorn
4) Puma
question Web server for production?
1) Same as development
2) Thin
3) Unicorn
4) Puma
question Database used in development?
1) SQLite
2) PostgreSQL
3) MySQL
4) MongoDB
question Template engine?
1) ERB
2) Haml
3) Slim (experimental)
question Unit testing?
1) Test::Unit
2) RSpec
question Integration testing?
1) None
2) RSpec with Capybara
3) Cucumber with Capybara
4) Turnip with Capybara
question Fixture replacement?
1) None
2) Factory Girl
3) Machinist
question Front-end framework?
1) None
2) Twitter Bootstrap
3) Zurb Foundation
4) Skeleton
5) Just normalize CSS for consistent styling
question Twitter Bootstrap version?
1) Twitter Bootstrap (Less)
2) Twitter Bootstrap (Sass)
question Add support for sending email?
1) None
2) Gmail
3) SMTP
4) SendGrid
5) Mandrill
question Authentication?
1) None
2) Devise
3) OmniAuth
question Devise modules?
1) Devise with default modules
2) Devise with Confirmable module
3) Devise with Confirmable and Invitable modules
question Authorization?
1) None
2) CanCan with Rolify
question Use a form builder gem?
1) None
2) SimpleForm
question Install a starter app?
1) None
2) Home Page
3) Home Page, User Accounts
4) Home Page, User Accounts, Admin Dashboard
extras Add 'therubyracer' JavaScript runtime (for Linux users without node.js)? (y/n)
extras Set a robots.txt file to ban spiders? (y/n) n
extras Create a project-specific rvm gemset and .rvmrc? (y/n) n
extras Create a GitHub repository? (y/n)
Switch to the application directory to examine and test what you’ve built.
$ cd myapp
For a “smoke test” to see if everything runs, display a list of Rake tasks.
$ rake -T
There’s no need to run bundle exec rake instead of rake when you are using rvm (see rvm and bundler integration).
If you’ve chosen WEBrick or Thin for your web server, can run the app by entering the command:
$ rails server
To see your application in action, open a browser window and navigate to http://localhost:3000/.
For the Unicorn web server:
$ unicorn
See the app at http://localhost:8080/.
For the Puma web server:
$ rails server puma
See the app at http://localhost:3000/.
If you’ve created a version of the application that sets up a default user, log in with:
- email: user@example.com
- password: changeme
You should delete or change any pre-configured logins before you deploy your application.
Some versions of the starter application will contain a suite of RSpec unit tests or Cucumber scenarios and step definitions.
After installing the application, run rake -T to check that rake tasks for RSpec and Cucumber are available.
Run rake spec to run all RSpec tests.
Run rake cucumber (or more simply, cucumber) to run all Cucumber scenarios.
Please send the author a message, create an issue, or submit a pull request if you want to contribute improved RSpec or Cucumber files.
For easy deployment, use a “platform as a service” provider such as:
For deployment on Heroku, see the article:
Problems? Please check both issues for the Rails Composer tool and the issues for the rails_apps_composer gem.
You should review the article Installing Rails to make sure you’ve updated all the components that are required to run Rails successfully.
If you get an error like this:
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.
composer Running 'after bundler' callbacks.
The template [...] could not be loaded.
Error: You have already activated ..., but your Gemfile requires ....
Using bundle exec may solve this.
It’s due to conflicting gem versions. See the article Rails Error: “You have already activated (…)”.
Are you getting an error “OpenSSL certificate verify failed” when you try to generate a new Rails app from an application template? See suggestions to resolve the error Certificate Verify Failed.
If you get a “segfault” when you try rails new, try removing and reinstalling rvm.
The rails new command creates a new Rails application. If you want to use the Rails Composer application template for every Rails application you build, you can set options for the rails new command in a .railsrc file in your home directory. Here’s how to set up a .railsrc file to use the template when you create a new Rails application:
# ~/.railsrc -m https://raw.github.com/RailsApps/rails-composer/master/composer.rb
The Rails Composer application template is assembled from recipes supplied by the rails_apps_composer gem. See the rails_apps_composer project to understand how the Rails Composer application works.
If you wish to change the template to generate an app with your own customized options, you can copy and edit the template file. However, it is better to use the rails_apps_composer gem to create a new application template. You’ll find newer versions of the recipes that make up the application template. You may find issues have been identified and (perhaps) fixed. And it will be easier to maintain your application template if you work from the rails_apps_composer gem.
To understand the code in these templates, take a look at Thor::Actions. Your recipes can use any methods provided by Thor::Actions or Rails::Generators::Actions. A big thanks to Yehuda Katz for creating Thor.
There is an unfinished Rails Guide on Rails Application Templates.
Also see:
Cooking Up A Custom Rails 3 Template (11 Oct 2010) by Andrea Singh
Rails Application Templates (16 Sept 2010) by Collin Schaafsma
Application templates in Rails 3 (18 Sept 2009) by Ben Scofield
Railscasts: App Templates in Rails 2.3 (9 Feb 2009) by Ryan Bates
Rails templates (4 Dec 2008) by Pratik Naik
There are many similar projects:
Problems? Please check both issues for the Rails Composer tool and the issues for the rails_apps_composer gem.
Your best source for help with problems is Stack Overflow. Your issue may have been encountered and addressed by others.
You can also try Rails Hotline, a free telephone hotline for Rails help staffed by volunteers.
Please make changes to the rails_apps_composer gem rather than changing the Rails Composer application template.
Daniel Kehoe initiated the RailsApps project and created the Rails Composer application template.
Is it useful to you? Follow the project on Twitter:
@rails_apps
and tweet some praise. I’d love to know you were helped out by what I’ve put together.
Copyright 2012-13 Daniel Kehoe