Since Rails 3.1 comes with CoffeeScript installed we get the gem ExecJsExecj that "lets you run JavaScript code from Ruby" but you need to have a Javascript Runtime installed. ExecJs chooses the best runtime that we have.
You can install any of these runtimes:
therubyracer - Google V8 embedded within Ruby
therubyrhino - Mozilla Rhino embedded within JRuby
Johnson - Mozilla SpiderMonkey embedded within Ruby
Mustang - Mustang V8 embedded within Ruby
Node.js
Apple JavaScriptCore - Included with Mac OS X
Mozilla SpiderMonkey
Microsoft Windows Script Host (JScript)
I recommend to install TheRubyRacer or Johnson because are easy to install, You can install them with gems.
I just installed the Rails 3.1.0.rc5 version and I found that the line:
config.active_record.identify_map = true
on application.rb has been removed, this must be cause that intruction was not working at all
Since Rails 3.1 comes with CoffeeScript installed we get the gem ExecJs Execj that "lets you run JavaScript code from Ruby" but you need to have a Javascript Runtime installed. ExecJs chooses the best runtime that we have.
You can install any of these runtimes:
I recommend to install TheRubyRacer or Johnson because are easy to install, You can install them with gems.