gistfile1.rb

class Views::Layouts::Application < Erector::Widget
  def render
    div :class => "header" do
      text "header"
    end

    div :class => "body" do
      inner_content
    end

    div :class => "footer" do
      text "footer"
    end
  end
end

class Views::Projects::Index < Views::Layouts::Application
  def inner_content
    text "inner content "
  end
end

# this will work
class ProjectsController < ApplicationController
  def index
    render_widget(Views::Projects::Index)
  end
end

# this will not work - throwing error 
#
#   undefined local variable or method `inner_content' for #<Views::Layouts::Application:0x3ad6f6c>
#
class ProjectsController < ApplicationController
  def index
  end
end