Rails 3 generators in gem

lib
  - generators
    - gemname
      install_generator.rb
      - templates
        (template files)
        

require 'rails/generators'

module ModuleName
  module Generators
    class InstallGenerator < Rails::Generators::NamedBase
      include Rails::Generators::Migration
      
      source_root File.expand_path("../templates", __FILE__)
      
      generators...
      
      def self.next_migration_number(path)
          @migration_number = current_migration_number(path) + 1
          ActiveRecord::Migration.next_migration_number(@migration_number)
      end
  
    end
   
  end
end

def generators
           
    generate("controller" , "nameOfController")
    
    copy_file "fileWantYouCopy.rb"   , "app/models/destiniAndNameToCopiedFile.rb"
    
    migration_template("modelOfMigrate.rb"  , "db/migrate/modelOfMigrateDestini.rb")
end

include Rails::Generators::Migration

def self.next_migration_number(path)
      @migration_number = current_migration_number(path) + 1
      ActiveRecord::Migration.next_migration_number(@migration_number)
end