Versatile nav_link helper for adding 'selected' class to navigation elements

nav_link.rb

module NavigationLinkHelper
  def navigation_link(title, path, html_options = {}, options = {})
    NavigationLink.new(request, title, path, html_options, options).to_html
  end

  class NavigationLink
    include ActionView::Helpers::UrlHelper

    def initialize(request, title, path, html_options, options)
      @request      = request
      @title        = title
      @path         = path
      @html_options = html_options
      @options      = options
    end
    
    def to_html
      html = if @options[:wrapper]
        puts wrapper_classes.inspect
        content_tag(@options[:wrapper], link, :class => wrapper_classes)
      else
        link
      end

      html.html_safe
    end

    private

    def default_link_classes
      @html_options[:class].to_s.split(/\s+/)
    end

    def wrapper_classes
      classes = @options[:wrapper_class].to_s.split(/\s+/)
      classes.present? ? classes : nil
    end

    def controller_for(path)
      Rails.application.routes.recognize_path(path)[:controller]
    end

    def controller_segment
      @options[:controller_segment] || @options[:url_segment]
    end

    def compare_path
      compare_path = @request.fullpath
      compare_path.gsub!(/\?.*/, '') if @options[:ignore_params]
      compare_path
    end

    def current_path
      current_path = url_for(@path)
      current_path.gsub!(/\?.*/, '') if @options[:ignore_params]
      current_path
    end

    def paths_match?
      compare_path == current_path
    end

    def segments_match?
      path_segment.present? && path_segment == current_segment
    end

    def path_segment
      if @options[:controller_segment]
        path_controller    = controller_for(path)
        path_controller.split('/')[controller_segment]
      elsif @options[:url_segment]
        compare_path.split('/')[controller_segment]
      end
    end

    def current_segment
      if @options[:controller_segment]
        current_controller = controller_for(@request.path)
        current_controller.split('/')[controller_segment]
      elsif @options[:url_segment]
        current_path.split('/')[controller_segment]
      end
    end

    def selected_class
      @options[:selected_class] || 'selected'
    end

    def link_classes
      additional_classes = selected? ? [selected_class] : []
      classes = default_link_classes + additional_classes
      classes.present? ? classes : nil
    end

    def selected?
      paths_match? || segments_match?
    end

    def link_options
      @html_options.merge(:class => link_classes)
    end

    def link
      link_to(@title, @path, link_options)
    end
  end
end