class ViewContext
  def initialize(*args)
    @_content_for = Hash.new
  end

  def content_for(name, content, &block)
    content = capture(&block) if block_given?
    @_content_for[name] = content
  end
end

class ActionController::Base
  def view_context
    ViewContext.new
  end
end


#####
@controller = ActionController::Base.new
@controller.view_context.content_for :foo, :bar
@controller.view_context.instance_variable_get "@_content_for" # => {}