stateful_link

= StatefulLink

StatefulLink is a helper that simplifies displaying stateful navigation links. State depends on current controller and action.

= Installation

Rails3 only Add the following line to your Gemfile:

gem 'stateful_link'

= Tutorial

Let we have RESTful PostsController and two navigation links in layout.

layouts/application.html.erb

• <%= link_to "Posts", posts_url %>
  • <%= link_to "New post", new_post_url %>

So, at every page we have same links. But in good form we should mark current user location by changing visual appearance of current and parent navigation links. For example, if user opens new post page, "New post" should be displayed as regular text, and "Posts" should become bold.

Solution:

posts_controller.rb

class PostsController < ApplicationController
end

application_helper.rb

module ApplicationHelper
  def navigation_link(label, active, chosen, url)
    stateful_link_to(
      active, 
      chosen,
      :active => proc { label },
      :chosen => proc { content_tag :b, link_to(label, url) },
      :inactive => proc { link_to label, url }
    )
  end
end

layouts/application.html.erb

<ul>
  <li>
    <%= navigation_link("Posts", "posts#index", "posts#*", posts_url) %>
    <ul>
      <%= navigation_link("New post", ["posts#new", "posts#create"], nil, new_post_url) %>
    </ul>
  </li>
</ul>

= Examples

posts/index.html.erb

<%= "we are in PostsController::index" if action_any_of?("posts#index") %> <%= "we are in PostsController::index" if action_any_of?("#index") %> <%= "action state is active" if action_state("#index") == :active %> <%= "action state is chosen" if action_state("#show", ["#index", "#edit", "#update"]) == :chosen %> <%= "action state is inactive" if action_state("users#index") == :inactive %>