Opal-Browser - Client side web development in pure Ruby, using Opal

This library aims to be a full-blown wrapper for all the browser API as defined by HTML5.

It provides a very JQuery-like interface to DOM, but itself it doesn't use nor require JQuery nor opal-jquery (which is an alternative library for interfacing the web browser). The main difference though is that Opal-Browser goes far beyond what JQuery does.

Usage

Gemfile

source 'https://rubygems.org/'

gem 'opal-browser'

Server side (config.ru, Rakefile, Rails, Sinatra, Roda, etc. - not needed for static compilation)

require 'opal-browser'
# Your server code here

Browser side

require 'opal'
require 'native'
require 'promise'
require 'browser/setup/full'

# Your Opal code here
$document.body << "Hello world!"

Static Compile Opal + Opal-Browser library

bundle exec opal -c -q opal-browser -p native -p promise -p browser/setup/full -e '#' -E > opal-browser.js

Static Compile your application

bundle exec opal -Oc -s opal -s native -s promise -s browser/setup/full app/application.rb > application.js

And load it in HTML!

<!DOCTYPE html>
<html>
<head>
  <title>My Application</title>
</head>
<body>
  <script src='opal-browser.js' onload='Opal.require("native"); Opal.require("promise"); Opal.require("browser/setup/full");'></script>
  <script src='application.js'></script>
</body>
</html>

See the examples/integrations/ directory for various ideas on how to quickly start development using opal-browser.

Features

This is a list of many currently wrapped features and some details on them.

DOM

DOM support is complete as far as I know, it has a very Nokogiri feel to it with obvious differences where relevant (for instance, event handling).

$document.ready do
  alert "yo dawg, I'm all loaded up in here"
end

It also supports a markaby inspired builder DSL (using Paggio) which generates DOM nodes directly instead of creating a string.

$document.ready do
  DOM {
    div.info {
      span.red "I'm all cooked up."
    }
  }.append_to($document.body)
end

Events

Add an event to a given element:

$document.at_css("button").on(:click) do |e|
  e.prevent # Prevent the default action (eg. form submission)
  # You can also use `e.stop` to stop propagating the event to other handlers.
  alert "Button clicked!"
end

Or add it to a parent element and use a delegator, so that an event gets fired when any button children of $document is clicked:

$document.on(:click, "button") do |e|
  e.prevent
  # e.on is a button that has been clicked
  e.on.inner_text = "Clicked!"
end

Run an event once with #one instead of #on, or disable an event with #off.

CSSOM

CSSOM support (using Paggio) is still incomplete but the useful parts are implemented, this includes a DSL for generating a CSS style and the same DSL is also used to change style declarations (which can either belong to a DOM::Element or a CSS::Rule::Style).

$document.body.style.apply {
  background color: 'black'
  color 'white'
  font family: 'Verdana'
}

AJAX & SJAX

The XMLHttpRequest API has been wrapped completely, it also optionally supports binary results as typed-arrays.

It easily allows for synchronous and asynchronous requests.

require 'browser/http'

Browser::HTTP.get "/something.json" do
  on :success do |res|
    alert res.json.inspect
  end
end

WebSocket

Websockets have been fully wrapped and they are easily configurable with blocks.

require 'browser/socket'

Browser::Socket.new 'ws://echo.websocket.org' do
  on :open do
    every 1 do
      puts "ping"
    end
  end

  on :message do |e|
    log "Received #{e.data}"
  end
end

EventSource

Event sources have been implemented and are easily configurable with blocks.

require 'browser/event_source'

Browser::EventSource.new '/events' do |es|
  es.on :message do |e|
    alert e.data
  end

  es.on :custom do |e|
    alert "custom #{e.data}"
  end
end

History

The HTML5 History API has been fully wrapped.

current = $window.history.current
$window.history.replace("?get=params")
$window.history.push("?get=params")
$window.history.back

$window.on :popstate do |e|
  p "User clicked a back button! He is now on #{$window.history.current}"
end

Storage

The HTML5 Storage API has been wrapped and it exports a single Storage class that uses the most appropriate and available API to store data locally.

require 'browser/storage'

$storage = $window.storage
$storage[:hello] = "world"

Database SQL

WebSQL has been fully wrapped (Chromium-only)

require 'browser/database/sql'

db = Browser::Database::SQL.new 'test'
db.transaction {|t|
  t.query('CREATE TABLE test(ID INTEGER PRIMARY KEY ASC, text TEXT)').then {
    t.query('INSERT INTO test (id, text) VALUES(?, ?)', 1, 'huehue')
  }.then {
    t.query('INSERT INTO test (id, text) VALUES(?, ?)', 2, 'jajaja')
  }.then {
    t.query('SELECT * FROM test')
  }.then {|r|
    r.each {|row|
      alert row.inspect
    }
  }
}

Browser support

Edge (Current - 3) to Current
Firefox (Current - 3) to Current
Chrome (Current - 3) to Current
Safari (Current - 3) to Current
Opera (Current - 3) to Current

Any problem above browsers should be considered and reported as a bug.

(Current - 3) to Current denotes that we support the current major stable version of the browser and 3 versions preceding it. For example, if the current version of a browser is 24.x, we support all versions between 21.x to 24.x.

We will accept compatibility patches for even earlier browser versions. Opal-Browser is written in such a way, that it integrates a robust compatibility check system, similar to Modernizr, and the history of this library goes even as far as supporting Internet Explorer 6.

See the polyfills documentation if you wish to polyfill some behaviors not supported by the ancient web browsers (like querySelectorAll).

License

(The MIT License)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

opal-browser

Runtime