rails 3.1 asset pipeline + stitch/CommonJS

application.js

// in app/assets/javascripts/application.js

//= require jquery
//= require jquery_ujs
//= require ./stitch_header
//= require_tree .

gistfile1.txt

I really like node.js & its commonjs module system.

I like the idea of stitch & stitch-rb http://alexmaccaw.co.uk/posts/2011/06/30/rails_js_packaging.html. 

But I'm also pragmatic... I also "like" the rails asset pipeline & its bandwaggonny weight.

So I combined the two approaches.

It'd be good to combine the two into a gem, but here's how it'd be shaped.

something.coffee

# in app/assets/javascripts/something.coffee

class exports.Something

stitch_header.js

// in app/assets/javascripts/stitch_header.js

(function(/*! Stitch !*/) {
  if (!this.require) {

    var modules = {},
        cache = {},
        require = function(name, root) {
          var module = cache[name], path = expand(root, name), fn;
          if (module) {
            return module;
          } else if (fn = modules[path] || modules[path = expand(path, './index')]) {
            module = {id: name, exports: {}};
            try {
              cache[name] = module.exports;

              fn(module.exports, function(name) {
                return require(name, dirname(path));
              }, module);

              return cache[name] = module.exports;
            } catch (err) {
              delete cache[name];
              throw err;
            }
          } else {
            throw 'module "' + name + '" not found';
          }
        }, 
        expand = function(root, name) {
          var results = [], parts, part;
          if (/^\.\.?(\/|$)/.test(name)) {
            parts = [root, name].join('/').split('/');
          } else {
            parts = name.split('/');
          }
          for (var i = 0, length = parts.length; i < length; i++) {
            part = parts[i];
            if (part == '..') {
              results.pop();
            } else if (part != '.' && part != '') {
              results.push(part);
            }
          }
          return results.join('/');
        },
        dirname = function(path) {
          return path.split('/').slice(0, -1).join('/');
        };

      this.require = function(name) {
        return require(name, '');
      }

    this.require.define = function(bundle) {
      for (var key in bundle)
        modules[key] = bundle[key];
    };
  }
}).call(this)

stitchy.rb

# in config/initializers/stitchy.rb

require 'stitchy_coffee_script_template'

YourApp::Application.config.after_initialize do
  YourApp::Application.assets.register_engine '.coffee', StitchyCoffeeScriptTemplate
end

stitchy_coffee_script_template.rb

# in lib/stitchy_coffee_script_template.rb

require 'tilt'

class StitchyCoffeeScriptTemplate < Tilt::Template
  self.default_mime_type = 'application/javascript'

   def self.engine_initialized?
    defined? ::CoffeeScript
  end

  def initialize_engine
    require_template_library 'coffee_script'
  end

  def prepare
    options[:bare] = true
  end

  def evaluate(scope, locals, &block)
    @output ||= "\nrequire.define({'#{ module_name(scope) }': function(exports, require, module) {\n" + CoffeeScript.compile(data, options) + "\n}});\n"
  end


  private
  # this might need to be customisable to generate the desired module names
  # this implementation lops off the first segment of the path
  def module_name(scope)
    scope.logical_path.split('/')[1..-1].join('/')
  end
end

your_file.coffee

# in app/assets/javascripts/your_file.coffee

{Something} = require('something')

class exports.YourApp extends Something
  

This code cannot work in Rails 3.1.0, I built a same gem for this: https://github.com/doitian/stitch_rails

YourApp::Application.config.after_initialize do
  YourApp::Application.assets.register_engine '.coffee', StitchyCoffeeScriptTemplate
end