inheritable rails views

inheritable_views.rb

# Make controller render and render partial fall back to ancestor
# controllers.  Very hackish because it overrides rails private
# methods.  Tested on rails 2.3.5 till 2.3.11.
module InheritableViewsHelper
  def render_partial_with_inheritance(options = {})
    if [String, Symbol, NilClass].find{|k| k === options[:partial]}
      if options[:partial].include?('/')
        render_partial_without_inheritance(options)
      else
        err = nil

        controller.class.all_controller_paths.each do |path|
          begin
            return render_partial_without_inheritance(options.merge(:partial => "#{path}/#{options[:partial]}"))
          rescue ActionView::MissingTemplate => ex
            err ||= ex
          end
        end

        raise err if err # re-raise first missing template error
      end
    else
      render_partial_without_inheritance(options)
    end
  end

  def self.included(other)
    other.alias_method_chain :render_partial, :inheritance
    other.memoize :render_partial_with_inheritance
  end
end

ActionView::Base.send(:include, InheritableViewsHelper)

module InheritableViewsController
  def default_template_with_inheritance(action_name = self.action_name)
    self.class.all_controller_paths.each do |path|
      template = self.view_paths.find_template("#{path}/#{action_name}", default_template_format) rescue nil
      return template if template
    end

    default_template_without_inheritance(action_name) # fall back to normal behaviour
  end

  def self.included(other)
    other.alias_method_chain :default_template, :inheritance
    other.extend ClassMethods
  end

  module ClassMethods
    # Insert path to inherit views from.
    def inherit_views_from(*controller_names)
      @inherited_controller_paths =
        controller_names + (@inherited_controller_paths || [])
    end

    # List controller paths to get views from.  The first being the
    # most significant.
    def all_controller_paths
      [controller_path] +
        (@inherited_controller_paths || []) +
        (superclass.respond_to?(:all_controller_paths) && superclass.all_controller_paths || [])
    end
  end
end

ActionController::Base.send(:include, InheritableViewsController)