• GitHub Project: http://github.com/cowboyd/therubyracer
• Mailing List: http://groups.google.com/group/therubyracer
• Documentation: GitHub Wiki and RubyDoc

This project is UNMAINTAINED.

Why?

• The binding to libv8 that therubyracer implements is quite tight, making updating libv8 a huge amount of work. mini_racer has a thinner interface for that reason.
• So many issues come from depot tools and the bespoke v8 toolchain, which only support what Google Chrome needs to support. libv8-node has been created to tackle those issues, leveraging the good work of Node.js people, and mini_racer uses that.

If you use a mini_racer that depends on libv8, please move to a more recent version.

If you use therubyracer and are thus stuck with v8 3.16, please move to mini_racer. If one of your dependencies uses therubyracer, please reach out to them so that they upgrade to mini_racer.

If there are needs coming from either libv8 or therubyracer that you feel are unmet by mini_racer + libv8-node, please open issues on their respective repositories.

Embed the V8 JavaScript interpreter into Ruby.

• Evaluate JavaScript from within Ruby
• Embed your Ruby objects into the JavaScript world
• Manipulate JavaScript objects and call JavaScript functions from Ruby
• API compatible with the The Ruby Rhino (for JRuby: http://github.com/cowboyd/therubyrhino)

gem install therubyracer 

then in your Ruby code

require 'v8' 

or if using bundler (as with Rails), add the following to your Gemfile

gem "therubyracer" 

evaluate some simple JavaScript

cxt = V8::Context.new cxt.eval('7 * 6') #=> 42 

access values inside your JavaScript context from Ruby

cxt.eval 'var val ={num: 5, isTruthy: function (arg){return !!arg }}' val = cxt[:val] #=> V8::Object cxt[:val] == cxt.scope.val #=> true val.num #=> 5 val.isTruthy(1) #=> true 

this includes references to JavaScript functions

truthy = val[:isTruthy] #=> V8::Function truthy.call(' ') #=> true truthy.call(0) #=> false 

embed values into the scope of your context

cxt['foo'] = "bar" cxt.eval('foo') # => "bar" 

embed Ruby code into your scope and call it from JavaScript

cxt["say"] = lambda{|this, word, times| word * times} cxt.eval("say('Hello', 3)") #=> HelloHelloHello 

embed a Ruby object into your scope and access its properties/methods from JavaScript

class MyMath def plus(lhs, rhs) lhs + rhs end end cxt['math'] = MyMath.new cxt.eval("math.plus(20,22)") #=> 42 

make a Ruby object be your global JavaScript scope.

math = MyMath.new V8::Context.new(:with => math) do |cxt| cxt.eval("plus(20,22)") #=> 42 end 

you can do the same thing with Object#eval_js

math.eval_js("plus(20,22)") 

In addition to just evaluating strings, you can also use streams, such as files.

evaluate bytes read from any File/IO object:

File.open("mysource.js") do |file| cxt.eval(file, "mysource.js") end 

or load it by filename

cxt.load("mysource.js") 

The Ruby Racer is designed to let you evaluate JavaScript as safely as possible unless you tell it to do something more dangerous. The default context is a hermetically sealed JavaScript environment with only the standard JavaScript objects and functions. Nothing from the Ruby world is accessible at all.

For Ruby objects that you explicitly embed into JavaScript, by default only the public methods belowObject are exposed by default. E.g.

class A def a "a" end def to_s super end end class B < A def b "b" end end V8::Context.new do |cxt| cxt['a'] = A.new cxt['b'] = B.new cxt.eval("a.a") # => 'a' cxt.eval("b.b") # => 'b' cxt.eval("b.a") # => 'a' cxt.eval("b.to_s") # => #<B:0x101776be8> (because A explicitly defined it) cxt.eval("b.object_id") #=> undefined, object_id is on Object end 

If needed, you can override the Ruby Access to allow whatever behavior you'd like.

More documentation can be found on the GitHub wiki

When running untrusted JavaScript code, you not only have to protect which functions it has access to, but also how much of your CPU it can consume. Take this simple, yet thoroughly malicious script:

while(true){}

It will loop forever and never return control to the calling Ruby thread. To protect against such JavaScript code that either deliberately or accidentally runs longer that it should, you can set an explicit timeout on your context. If the code runs longer that the allowed timeout, then it will throw an exception. Note that this exception could be raised at any point in the execution of the JavaScript.

To specify the timeout (in milliseconds), pass in the timeout option to the constructor.

cxt=V8::Context.newtimeout: 700cxt.eval"while (true);"#= exception after 700ms!

The Ruby Racer requires the V8 Javascript engine, but it offloads the handling of this dependency to the libv8 gem. Because libv8 is now a gem dependency, you do not need a separate libv8 entry in your project's Gemfile.

Please see libv8 for V8 runtime installation options.

git clone git://github.com/cowboyd/therubyracer.git cd therubyracer bundle install rake compile 

(The MIT License)

Copyright (c) 2009,2010,2011,2012 Charles Lowell

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.