mirror of https://github.com/rails/rails
84 lines
3.9 KiB
Markdown
84 lines
3.9 KiB
Markdown
## Welcome to Rails
|
|
|
|
Rails is a web-application framework that includes everything needed to
|
|
create database-backed web applications according to the
|
|
[Model-View-Controller (MVC)](http://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller)
|
|
pattern.
|
|
|
|
Understanding the MVC pattern is key to understanding Rails. MVC divides your
|
|
application into three layers, each with a specific responsibility.
|
|
|
|
The _Model layer_ represents your domain model (such as Account, Product,
|
|
Person, Post, etc.) and encapsulates the business logic that is specific to
|
|
your application. In Rails, database-backed model classes are derived from
|
|
`ActiveRecord::Base`. Active Record allows you to present the data from
|
|
database rows as objects and embellish these data objects with business logic
|
|
methods. Although most Rails models are backed by a database, models can also
|
|
be ordinary Ruby classes, or Ruby classes that implement a set of interfaces
|
|
as provided by the Active Model module. You can read more about Active Record
|
|
in its [README](activerecord/README.rdoc).
|
|
|
|
The _Controller layer_ is responsible for handling incoming HTTP requests and
|
|
providing a suitable response. Usually this means returning HTML, but Rails controllers
|
|
can also generate XML, JSON, PDFs, mobile-specific views, and more. Controllers load and
|
|
manipulate models, and render view templates in order to generate the appropriate HTTP response.
|
|
In Rails, incoming requests are routed by Action Dispatch to an appropriate controller, and
|
|
controller classes are derived from `ActionController::Base`. Action Dispatch and Action Controller
|
|
are bundled together in Action Pack. You can read more about Action Pack in its
|
|
[README](actionpack/README.rdoc).
|
|
|
|
The _View layer_ is composed of "templates" that are responsible for providing
|
|
appropriate representations of your application's resources. Templates can
|
|
come in a variety of formats, but most view templates are HTML with embedded
|
|
Ruby code (ERB files). Views are typically rendered to generate a controller response,
|
|
or to generate the body of an email. In Rails, View generation is handled by Action View.
|
|
You can read more about Action View in its [README](actionview/README.rdoc).
|
|
|
|
Active Record, Action Pack, and Action View can each be used independently outside Rails.
|
|
In addition to them, Rails also comes with Action Mailer ([README](actionmailer/README.rdoc)), a library
|
|
to generate and send emails; and Active Support ([README](activesupport/README.rdoc)), a collection of
|
|
utility classes and standard library extensions that are useful for Rails, and may also be used
|
|
independently outside Rails.
|
|
|
|
## Getting Started
|
|
|
|
1. Install Rails at the command prompt if you haven't yet:
|
|
|
|
gem install rails
|
|
|
|
2. At the command prompt, create a new Rails application:
|
|
|
|
rails new myapp
|
|
|
|
where "myapp" is the application name.
|
|
|
|
3. Change directory to `myapp` and start the web server:
|
|
|
|
cd myapp
|
|
rails server
|
|
|
|
Run with `--help` or `-h` for options.
|
|
|
|
4. Using a browser, go to `http://localhost:3000` and you'll see:
|
|
"Welcome aboard: You're riding Ruby on Rails!"
|
|
|
|
5. Follow the guidelines to start developing your application. You may find
|
|
the following resources handy:
|
|
* [Getting Started with Rails](http://guides.rubyonrails.org/getting_started.html)
|
|
* [Ruby on Rails Guides](http://guides.rubyonrails.org)
|
|
* [The API Documentation](http://api.rubyonrails.org)
|
|
* [Ruby on Rails Tutorial](http://ruby.railstutorial.org/ruby-on-rails-tutorial-book)
|
|
|
|
## Contributing
|
|
|
|
We encourage you to contribute to Ruby on Rails! Please check out the
|
|
[Contributing to Ruby on Rails guide](http://edgeguides.rubyonrails.org/contributing_to_ruby_on_rails.html) for guidelines about how to proceed. [Join us!](http://contributors.rubyonrails.org)
|
|
|
|
## Code Status
|
|
|
|
* [](https://travis-ci.org/rails/rails)
|
|
|
|
## License
|
|
|
|
Ruby on Rails is released under the [MIT License](http://www.opensource.org/licenses/MIT).
|