ERB usage in a rake task

sample_erb_usage.rb

  require 'rake'
  require 'erb'  

  desc 'Builds manifest.js files for models, and collections.'
  task :build_class_manifests do 
    STDOUT.sync = true
    
    # Build Class Manifests First
    classes = ['initializers', 'config', 'models', 'collections']
    
    classes.each do |aclass|
      puts "Building #{aclass.capitalize} Manifest"
      File.open(File.join('www', 'scripts', aclass, 'manifest.js'), 'w') { |build_file|
        # Place to store all of the models
        files = []

        # Grab all of the .js files
        Dir.glob(File.join('www', 'scripts', aclass, '**', '*.js')) { |path|
          parts = File.split(path)

          files <<  File.join(parts[0].split(File::SEPARATOR) - ['www', 'scripts'] + [File.basename(parts[1], '.js')]) unless parts[1] == 'manifest.js'
        }

        template = <<-EOF
// Automatically Generated File
define(
  // require shovel
  [
    'common/shovel', 
    <% files.each do |file| %>'<%= file %>'<%= ',\n    ' unless file == files.last %><% end %>
  ],

  function (shovel){
    shovel.debug('Loaded <%= aclass.capitalize %>');

    $(document).trigger('shovel_<%= aclass %>_loaded');
  }
);
EOF

        buffer = ERB.new(template).result(binding)
        build_file.puts buffer
      }
    end