Example of how to use ERB and DATA in Ruby. Handy combination.

renderable_file.rb

require 'ostruct'
require 'erb'

class RenderableFile
  def self.get_data(name = nil)
    unless const_defined?(:DATA)
      const_set(:DATA, File.open( __FILE__ ).read.split( /^__END__\n/, 2 ).last)
    end
    if name
      DATA.split( /^#{name}\n/, 2 ).last
    end
  end

  TEMPLATE = get_data(:__ERB__)

  def erb
    @erb ||= ERB.new(TEMPLATE, nil, '-')
  end

  def erb_binding
    list = ["it can do this", "it's in stdlib"]
    OpenStruct.new(list: list).instance_eval { binding }
  end

  def render
    erb.result(erb_binding)
  end
end

__END__
# Yay ERB!
__ERB__
# Generated by XXXX. Do not edit.

<% list.each do |item| %>
  ERB is awesome because: <%= item %>
<% end %>