Controller-less rails template

remplate.rb

class Remplate < AbstractController::Base
  include AbstractController::Rendering
  include AbstractController::Layouts
  include AbstractController::Helpers
  include AbstractController::Translation
  include AbstractController::AssetPaths
  include Rails.application.routes.url_helpers

  self.view_paths = "app/views" # TODO: get it from Rails.application if available

  # TODO: de-uglify
  def self.prefixes_for_directory(path)
    directories = []
    dir         = path
    begin
      directories << dir
      dir = File.dirname(dir)
    end until dir == "." unless dir == "."

    directories
  end

  # TODO: verify that that's the mechanism used by rails
  def self.prefixes_for_controller(controller)
    controller.ancestors.grep(ApplicationController.singleton_class).map(&:controller_path)
  end

  # Render a controller action without instanciating the controller
  # @example
  #    Remplate.view(Admin::UsersController, 'index').render users: User.all
  def self.view(controller, action, params=nil, options=nil)
    options = options ? options.dup : {}
    options[:prefixes] ||= prefixes_for_controller(controller)
    options[:template]  = action

    new(options)
  end

  # Render a template from string, similar to `render string: "template"`
  # @example
  #    Remplate.string("%h1 Welcome \#{name}").render name: "Luser"
  #
  # TODO: dysfunctional
  def self.string(string, options={})
    new(options.merge(string: string))
  end

  # Render a file template, using its path to determine where partials are
  # @example
  #   Remplate.file('users/index.html.haml').render users: User.all
  def self.file(path, options={})
    dir, file = File.split(path)

    new(options.merge(template: path, prefixes: ['', *prefixes_for_directory(dir)]))
  end

  def initialize(options={})
    @options = options
    @_prefixes = @options[:prefixes] || [] # TODO: for some reason it's not picked up from the options, figure out why
    super()
  end

  # @return [Remplate] a new Remplate instance with the additional options applied
  def with(options)
    self.class.new(@options.merge(options))
  end

  def render(locals={})
    options = @options.merge(locals: locals)
    super(options)
  end
end