therubyracer
DESCRIPTION:
Embed the V8 Javascript interpreter into Ruby.
FEATURES/PROBLEMS:
-
Evaluate Javascript from with in Ruby
-
Embed your Ruby objects into the Javascript world
-
Manipulate JavaScript objects and call JavaScript functions from Ruby
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API compatible with the The Ruby Rhino (for JRuby: github.com/cowboyd/therubyrhino)
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Currently ALPHA software.
SYNOPSIS:
require 'v8'
# evaluate some simple javascript
V8.eval("7 * 6") #=> 42
# embed values into the scope of your context
V8::Context.open do |cxt|
cxt['foo'] = "bar"
cxt.eval('foo') # => "bar"
end
# evaluate a ruby function from javascript
V8::Context.open do |context|
context["say"] = lambda {|word, times| word * times}
context.eval("say("Hello", 3)") #=> HelloHelloHello
end
# embed a ruby object into your javascript environment
class MyMath
def plus(lhs, rhs)
lhs + rhs
end
end
V8::Context.open do |context|
context["math"] = MyMath.new
context.eval("math.plus(20,22)") #=> 42
end
# make a ruby object be your javascript environment
math = MyMath.new
V8::Context.open(:with => math) do |context|
context.eval("plus(20,22)") #=> 42
end
#or the equivalent
math.eval_js("plus(20,22)")
# Configure your embedding setup
#COMING SOON!
# Make your standard objects (Object, String, etc...) immutable
V8::Context.open(:sealed => true) do |context|
context.eval("Object.prototype.toString = function() {}") # this is an error!
end
#COMING SOON!
#limit the number of instructions that can be executed in order to prevent
#rogue scripts
V8::Context.open do |context|
context.instruction_limit = 100000
context.eval("while (true);") # => Error!
end
Different ways of loading javascript source
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|
eval_js file, "mysource.js"
end
# or load it by filename
V8::Context.open do |context|
context.load("mysource.js")
end
Safe by default
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, only the public
methods *defined in their classes* are exposed by default. E.g.
class A
def a
"a"
end
end
class B < A
def b
"b"
end
end
V8::Context.open do |cxt|
cxt['a'] = A.new
cxt['b'] = B.new
cxt.eval("a.a()") # => 'a'
cxt.eval("b.b()") # => 'b'
cxt.eval("b.a()") # => 'TypeError: undefined property 'a' is not a function'
end
REQUIREMENTS:
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libv8 >= 0.4.0
INSTALL:
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download and build V8: code.google.com/apis/v8/build.html
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Be sure to build it as a static library and with the same architecture as your ruby executable. e.g.
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scons library=static arch=x64
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sudo gem install therubyracer –with-v8-include=/path/to/v8/source/include –with-v8-lib=/path/to/v8/source
LICENSE:
(The MIT License)
Copyright © 2009 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.