mirror of
https://github.com/rails/rails.git
synced 2022-11-09 12:12:34 -05:00
103 lines
4.9 KiB
Markdown
103 lines
4.9 KiB
Markdown
# Welcome to Rails
|
||
|
||
## What's Rails?
|
||
|
||
Rails is a web-application framework that includes everything needed to
|
||
create database-backed web applications according to the
|
||
[Model-View-Controller (MVC)](https://en.wikipedia.org/wiki/Model-view-controller)
|
||
pattern.
|
||
|
||
Understanding the MVC pattern is key to understanding Rails. MVC divides your
|
||
application into three layers: Model, View, and Controller, each with a specific responsibility.
|
||
|
||
## Model layer
|
||
|
||
The _**Model layer**_ represents the domain model (such as Account, Product,
|
||
Person, Post, etc.) and encapsulates the business logic specific to
|
||
your application. In Rails, database-backed model classes are derived from
|
||
`ActiveRecord::Base`. [Active Record](activerecord/README.rdoc) 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](activemodel/README.rdoc) module.
|
||
|
||
## Controller layer
|
||
|
||
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](actionpack/README.rdoc).
|
||
|
||
## View layer
|
||
|
||
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](actionview/README.rdoc).
|
||
|
||
## Frameworks and libraries
|
||
|
||
[Active Record](activerecord/README.rdoc), [Active Model](activemodel/README.rdoc), [Action Pack](actionpack/README.rdoc), and [Action View](actionview/README.rdoc) can each be used independently outside Rails.
|
||
In addition to that, Rails also comes with [Action Mailer](actionmailer/README.rdoc), a library
|
||
to generate and send emails; [Action Mailbox](actionmailbox/README.md), a library to receive emails within a Rails application;
|
||
[Active Job](activejob/README.md), a framework for declaring jobs and making them run on a variety of queuing
|
||
backends; [Action Cable](actioncable/README.md), a framework to
|
||
integrate WebSockets with a Rails application; [Active Storage](activestorage/README.md), a library to attach cloud
|
||
and local files to Rails applications; [Action Text](actiontext/README.md), a library to handle rich text content;
|
||
and [Active Support](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
|
||
$ bin/rails server
|
||
|
||
Run with `--help` or `-h` for options.
|
||
|
||
4. Go to `http://localhost:3000` and you'll see:
|
||
"Yay! You’re on Rails!"
|
||
|
||
5. Follow the guidelines to start developing your application. You may find
|
||
the following resources handy:
|
||
* [Getting Started with Rails](https://guides.rubyonrails.org/getting_started.html)
|
||
* [Ruby on Rails Guides](https://guides.rubyonrails.org)
|
||
* [The API Documentation](https://api.rubyonrails.org)
|
||
|
||
## Contributing
|
||
|
||
[](https://www.codetriage.com/rails/rails)
|
||
|
||
We encourage you to contribute to Ruby on Rails! Please check out the
|
||
[Contributing to Ruby on Rails guide](https://edgeguides.rubyonrails.org/contributing_to_ruby_on_rails.html) for guidelines about how to proceed. [Join us!](https://contributors.rubyonrails.org)
|
||
|
||
Trying to report a possible security vulnerability in Rails? Please
|
||
check out our [security policy](https://rubyonrails.org/security/) for
|
||
guidelines about how to proceed.
|
||
|
||
Everyone interacting in Rails and its sub-projects' codebases, issue trackers, chat rooms, and mailing lists is expected to follow the Rails [code of conduct](https://rubyonrails.org/conduct/).
|
||
|
||
## Code Status
|
||
|
||
[](https://buildkite.com/rails/rails)
|
||
|
||
## License
|
||
|
||
Ruby on Rails is released under the [MIT License](https://opensource.org/licenses/MIT).
|