docs/index
Opal Guides for v1.6.dev
These guides are designed to make you immediately productive with Opal, and to help you understand how all of the pieces fit together.
The guides for earlier releases are available here.
Start here
Getting Started with Opal
Everything you need to know to install Opal and create your first application.
Using JavaScript Features from Ruby
Async
Learn more about JavaScript async/await support in Opal and how you can use it to avoid explicit callbacks and promises.
Promises
How to interact and leverage the power of JavaScript promises from Ruby.
Source Maps
How to enable and consume source-maps for your Opal application and be able to debug your Ruby scripts right inside the browser.
Using Ruby Features
Working with ERB and Haml Templates
How to work with template libraries in Opal, be it to share the templates with the server or to write your own.
Working with Frameworks
Rails
How to use opal-rails to use Opal as the JavaScript compiler.
Static Applications
The most basic setup for a static Opal powered website that can be hosted anywhere.
Sinatra
Serve Opal applications through Sinatra and opal-sprockets.
Roda + Sprockets
Setup Roda + Sprockets to start serving Opal applications from Roda.
Interacting with Other Libraries
jQuery
This guide covers the opal-jquery wrapper around the popular library.
RSpec
Write specs for your Opal code RSpec and run them on Node.js or in a browser.
Using Sprockets
Configure the long-lasting asset handler to work with Opal.
Digging Deeper
Configuring Gems
How to make your gem work in Opal and differentiate code for the JavaScript environment.
Compiler
A very general overview of how the Opal compiler works.
Compiled Ruby
This guide documents how each part of Ruby is mapped to JavaScript internally.
Compiler File Loading Directives
The Opal compiler supports some special directives that can optimize or
enhance the output of compiled Ruby code to suit the Ruby environment.
Using the Opal parser inside a JavaScript environment
This guide documents how to parse and run Ruby scripts within a browser or any supported JavaScript environment
Encoding
(WIP) How to handle encoding within Opal in the browser and in the code.
Running code in a Headless Chrome
How to run your Opal application in a headless Chrome from the CLI instead of Node.js.
Unsupported Features
Some things that are very difficult, impossible, or outright incompatible with a JavaScript environment.
Releases
Upgrading Opal
This guide provides steps to be followed when you upgrade your applications to a newer version of Opal.
Releasing Instructions
(WIP) A step-by-step guide on who to release a new version of Opal.