Integrating Handlebars into Jammit

jammit-handlebars.js

(function(jq) {

window.Jammit = {
  // At the top of the Javascript file that Jammit assembles, this function is
  // called once for each Mustache template that Jammit encounters. It does two
  // things:
  //
  // 1) It tells Handlebars about the template by putting its raw content in
  //    Handlebars.partials. This makes it  possible for any Mustache template
  //    to refer to another via a partial.
  // 2) It stores the render function for the template in the global JST
  //    object, so that you can actually render the template in your code.
  //
  // name    - The String name of a template, to be stored under JST.
  //           May contain slashes (e.g. "foo/bar").
  // content - A String Mustache template.
  //
  // Returns nothing.
  //
  storeTemplate: function(name, content) {
    // Add the template content to the list of Handlebars partials.
    // Convert slashes to dots in the template name because this is how
    // Handlebars resolves partial names.
    Handlebars.partials[name.replace(/\//g, ".")] = content;

    // Compile the template right away so that future calls do not have to do
    // this. Handlebars.compile() returns a function that can then be called to
    // render the template - such as `JST[name](data, options)`.
    var render = Handlebars.compile(content);

    JST[name] = function(context, options) {
      if (arguments.length) {
        // Render the template to a string.
        return render(context, options);
      }
      else {
        // Return the raw template with no arguments. This is useful (??) for
        // rendering partials. (Here for backward compatibility.)
        return content;
      }
    }
  }
};

})(window.jQuery);

jammit_ext.rb

module Jammit
  class Compressor
    # Override so that instead of directly setting JST[name], we call a custom
    # Javascript function which will do two things: 1) store the raw content of
    # each template and give it to Handlebars in such a way that partials will
    # work; and 2) precompile templates so that rendering them is faster.
    #
    def compile_jst(paths)
      namespace   = Jammit.template_namespace
      paths       = paths.grep(Jammit.template_extension_matcher).sort
      base_path   = find_base_path(paths)
      compiled    = paths.map do |path|
        contents  = read_binary_file(path)
        contents  = contents.gsub(/\r?\n/, "\\n").gsub("'", '\\\\\'')
        name      = template_name(path, base_path)
        "Jammit.storeTemplate('#{name}', '#{contents}');"
      end
      compiler = Jammit.include_jst_script ? read_binary_file(DEFAULT_JST_SCRIPT) : '';
      setup_namespace = "#{namespace} = #{namespace} || {};"
      [JST_START, setup_namespace, compiler, compiled, JST_END].flatten.join("\n")
    end
  end
end