ERB binding

basic_erb.rb

require 'erb'

class BasicErb
  def initialize(template)
    @template = template
  end

  def greeting
    "Hello World!"
  end

  def create!
    File.write('index.html', ERB.new(@template).result(binding))
  end
end

template = File.read('./index.html.erb')
basic_erb = BasicErb.new(template)
basic_erb.create!

index.html.erb

<h1><%= greeting %></h1>